50 files changed, 7310 insertions, 2091 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index fe5f674d7a7d..57963c6063d1 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -153,7 +153,7 @@ config MEMORY_HOTREMOVE
 #
 config PAGEFLAGS_EXTENDED
         def_bool y
-        depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM
+        depends on 64BIT || SPARSEMEM_VMEMMAP || !SPARSEMEM
 
 # Heavily threaded applications may benefit from splitting the mm-wide
 # page_table_lock, so that faults on different parts of the user address
@@ -214,6 +214,20 @@ config HAVE_MLOCKED_PAGE_BIT
 config MMU_NOTIFIER
         bool
 
+config KSM
+        bool "Enable KSM for page merging"
+        depends on MMU
+        help
+          Enable Kernel Samepage Merging: KSM periodically scans those areas
+          of an application's address space that an app has advised may be
+          mergeable.  When it finds pages of identical content, it replaces
+          the many instances by a single resident page with that content, so
+          saving memory until one or another app needs to modify the content.
+          Recommended for use with KVM, or with other duplicative applications.
+          See Documentation/vm/ksm.txt for more information: KSM is inactive
+          until a program has madvised that an area is MADV_MERGEABLE, and
+          root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set).
+
 config DEFAULT_MMAP_MIN_ADDR
         int "Low address space to protect from user allocation"
         default 4096
@@ -232,6 +246,22 @@ config DEFAULT_MMAP_MIN_ADDR
           This value can be changed after boot using the
           /proc/sys/vm/mmap_min_addr tunable.
 
+config ARCH_SUPPORTS_MEMORY_FAILURE
+        bool
+
+config MEMORY_FAILURE
+        depends on MMU
+        depends on ARCH_SUPPORTS_MEMORY_FAILURE
+        bool "Enable recovery from hardware memory errors"
+        help
+          Enables code to recover from some memory failures on systems
+          with MCA recovery. This allows a system to continue running
+          even when some of its memory has uncorrected errors. This requires
+          special hardware support and typically ECC memory.
+
+config HWPOISON_INJECT
+        tristate "Poison pages injector"
+        depends on MEMORY_FAILURE && DEBUG_KERNEL
 
 config NOMMU_INITIAL_TRIM_EXCESS
         int "Turn on mmap() excess space trimming before booting"
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index aa99fd1f7109..af7cfb43d2f0 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -6,7 +6,7 @@ config DEBUG_PAGEALLOC
         ---help---
           Unmap pages from the kernel linear mapping after free_pages().
           This results in a large slowdown, but helps to find certain types
-          of memory corruptions.
+          of memory corruption.
 
 config WANT_PAGE_DEBUG_FLAGS
         bool
@@ -17,11 +17,11 @@ config PAGE_POISONING
         depends on !HIBERNATION
         select DEBUG_PAGEALLOC
         select WANT_PAGE_DEBUG_FLAGS
-        help
+        ---help---
            Fill the pages with poison patterns after free_pages() and verify
            the patterns before alloc_pages(). This results in a large slowdown,
-           but helps to find certain types of memory corruptions.
+           but helps to find certain types of memory corruption.
 
-           This option cannot enalbe with hibernation. Otherwise, it will get
-           wrong messages for memory corruption because the free pages are not
-           saved to the suspend image.
+           This option cannot be enabled in combination with hibernation as
+           that would result in incorrect warnings of memory corruption after
+           a resume because free pages are not saved to the suspend image.
diff --git a/mm/Makefile b/mm/Makefile
index 5e0bd6426693..ebf849042ed3 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -5,16 +5,16 @@
 mmu-y                   := nommu.o
 mmu-$(CONFIG_MMU)       := fremap.o highmem.o madvise.o memory.o mincore.o \
                            mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
-                           vmalloc.o
+                           vmalloc.o pagewalk.o
 
 obj-y                   := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
-                           maccess.o page_alloc.o page-writeback.o pdflush.o \
+                           maccess.o page_alloc.o page-writeback.o \
                            readahead.o swap.o truncate.o vmscan.o shmem.o \
                            prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
-                           page_isolation.o mm_init.o $(mmu-y)
+                           page_isolation.o mm_init.o mmu_context.o \
+                           $(mmu-y)
 obj-y += init-mm.o
 
-obj-$(CONFIG_PROC_PAGE_MONITOR) += pagewalk.o
 obj-$(CONFIG_BOUNCE)    += bounce.o
 obj-$(CONFIG_SWAP)      += page_io.o swap_state.o swapfile.o thrash.o
 obj-$(CONFIG_HAS_DMA)   += dmapool.o
@@ -25,6 +25,7 @@ obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
 obj-$(CONFIG_TMPFS_POSIX_ACL) += shmem_acl.o
 obj-$(CONFIG_SLOB) += slob.o
 obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
+obj-$(CONFIG_KSM) += ksm.o
 obj-$(CONFIG_PAGE_POISONING) += debug-pagealloc.o
 obj-$(CONFIG_SLAB) += slab.o
 obj-$(CONFIG_SLUB) += slub.o
@@ -33,12 +34,14 @@ obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
 obj-$(CONFIG_FS_XIP) += filemap_xip.o
 obj-$(CONFIG_MIGRATION) += migrate.o
-ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
+ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
 obj-$(CONFIG_SMP) += percpu.o
 else
 obj-$(CONFIG_SMP) += allocpercpu.o
 endif
 obj-$(CONFIG_QUICKLIST) += quicklist.o
 obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
+obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
+obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
 obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c
index dfdee6a47359..df34ceae0c67 100644
--- a/mm/allocpercpu.c
+++ b/mm/allocpercpu.c
@@ -5,6 +5,8 @@
  */
 #include <linux/mm.h>
 #include <linux/module.h>
+#include <linux/bootmem.h>
+#include <asm/sections.h>
 
 #ifndef cache_line_size
 #define cache_line_size()       L1_CACHE_BYTES
@@ -147,3 +149,29 @@ void free_percpu(void *__pdata)
         kfree(__percpu_disguise(__pdata));
 }
 EXPORT_SYMBOL_GPL(free_percpu);
+
+/*
+ * Generic percpu area setup.
+ */
+#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+
+EXPORT_SYMBOL(__per_cpu_offset);
+
+void __init setup_per_cpu_areas(void)
+{
+        unsigned long size, i;
+        char *ptr;
+        unsigned long nr_possible_cpus = num_possible_cpus();
+
+        /* Copy section for each CPU (we discard the original) */
+        size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
+        ptr = alloc_bootmem_pages(size * nr_possible_cpus);
+
+        for_each_possible_cpu(i) {
+                __per_cpu_offset[i] = ptr - __per_cpu_start;
+                memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+                ptr += size;
+        }
+}
+#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index c86edd244294..5a37e2055717 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -1,8 +1,11 @@
 
 #include <linux/wait.h>
 #include <linux/backing-dev.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
+#include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/module.h>
 #include <linux/writeback.h>
@@ -14,6 +17,7 @@ void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 EXPORT_SYMBOL(default_unplug_io_fn);
 
 struct backing_dev_info default_backing_dev_info = {
+        .name           = "default",
         .ra_pages       = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE,
         .state          = 0,
         .capabilities   = BDI_CAP_MAP_COPY,
@@ -23,6 +27,24 @@ EXPORT_SYMBOL_GPL(default_backing_dev_info);
 
 static struct class *bdi_class;
 
+/*
+ * bdi_lock protects updates to bdi_list and bdi_pending_list, as well as
+ * reader side protection for bdi_pending_list. bdi_list has RCU reader side
+ * locking.
+ */
+DEFINE_SPINLOCK(bdi_lock);
+LIST_HEAD(bdi_list);
+LIST_HEAD(bdi_pending_list);
+
+static struct task_struct *sync_supers_tsk;
+static struct timer_list sync_supers_timer;
+
+static int bdi_sync_supers(void *);
+static void sync_supers_timer_fn(unsigned long);
+static void arm_supers_timer(void);
+
+static void bdi_add_default_flusher_task(struct backing_dev_info *bdi);
+
 #ifdef CONFIG_DEBUG_FS
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
@@ -37,9 +59,29 @@ static void bdi_debug_init(void)
 static int bdi_debug_stats_show(struct seq_file *m, void *v)
 {
         struct backing_dev_info *bdi = m->private;
+        struct bdi_writeback *wb;
         unsigned long background_thresh;
         unsigned long dirty_thresh;
         unsigned long bdi_thresh;
+        unsigned long nr_dirty, nr_io, nr_more_io, nr_wb;
+        struct inode *inode;
+
+        /*
+         * inode lock is enough here, the bdi->wb_list is protected by
+         * RCU on the reader side
+         */
+        nr_wb = nr_dirty = nr_io = nr_more_io = 0;
+        spin_lock(&inode_lock);
+        list_for_each_entry(wb, &bdi->wb_list, list) {
+                nr_wb++;
+                list_for_each_entry(inode, &wb->b_dirty, i_list)
+                        nr_dirty++;
+                list_for_each_entry(inode, &wb->b_io, i_list)
+                        nr_io++;
+                list_for_each_entry(inode, &wb->b_more_io, i_list)
+                        nr_more_io++;
+        }
+        spin_unlock(&inode_lock);
 
         get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi);
 
@@ -49,12 +91,22 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
                    "BdiReclaimable:   %8lu kB\n"
                    "BdiDirtyThresh:   %8lu kB\n"
                    "DirtyThresh:      %8lu kB\n"
-                   "BackgroundThresh: %8lu kB\n",
+                   "BackgroundThresh: %8lu kB\n"
+                   "WritebackThreads: %8lu\n"
+                   "b_dirty:          %8lu\n"
+                   "b_io:             %8lu\n"
+                   "b_more_io:        %8lu\n"
+                   "bdi_list:         %8u\n"
+                   "state:            %8lx\n"
+                   "wb_mask:          %8lx\n"
+                   "wb_list:          %8u\n"
+                   "wb_cnt:           %8u\n",
                    (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)),
                    (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)),
-                   K(bdi_thresh),
-                   K(dirty_thresh),
-                   K(background_thresh));
+                   K(bdi_thresh), K(dirty_thresh),
+                   K(background_thresh), nr_wb, nr_dirty, nr_io, nr_more_io,
+                   !list_empty(&bdi->bdi_list), bdi->state, bdi->wb_mask,
+                   !list_empty(&bdi->wb_list), bdi->wb_cnt);
 #undef K
 
         return 0;
@@ -185,6 +237,13 @@ static int __init default_bdi_init(void)
 {
         int err;
 
+        sync_supers_tsk = kthread_run(bdi_sync_supers, NULL, "sync_supers");
+        BUG_ON(IS_ERR(sync_supers_tsk));
+
+        init_timer(&sync_supers_timer);
+        setup_timer(&sync_supers_timer, sync_supers_timer_fn, 0);
+        arm_supers_timer();
+
         err = bdi_init(&default_backing_dev_info);
         if (!err)
                 bdi_register(&default_backing_dev_info, NULL, "default");
@@ -193,6 +252,279 @@ static int __init default_bdi_init(void)
 }
 subsys_initcall(default_bdi_init);
 
+static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi)
+{
+        memset(wb, 0, sizeof(*wb));
+
+        wb->bdi = bdi;
+        wb->last_old_flush = jiffies;
+        INIT_LIST_HEAD(&wb->b_dirty);
+        INIT_LIST_HEAD(&wb->b_io);
+        INIT_LIST_HEAD(&wb->b_more_io);
+}
+
+static void bdi_task_init(struct backing_dev_info *bdi,
+                          struct bdi_writeback *wb)
+{
+        struct task_struct *tsk = current;
+
+        spin_lock(&bdi->wb_lock);
+        list_add_tail_rcu(&wb->list, &bdi->wb_list);
+        spin_unlock(&bdi->wb_lock);
+
+        tsk->flags |= PF_FLUSHER | PF_SWAPWRITE;
+        set_freezable();
+
+        /*
+         * Our parent may run at a different priority, just set us to normal
+         */
+        set_user_nice(tsk, 0);
+}
+
+static int bdi_start_fn(void *ptr)
+{
+        struct bdi_writeback *wb = ptr;
+        struct backing_dev_info *bdi = wb->bdi;
+        int ret;
+
+        /*
+         * Add us to the active bdi_list
+         */
+        spin_lock_bh(&bdi_lock);
+        list_add_rcu(&bdi->bdi_list, &bdi_list);
+        spin_unlock_bh(&bdi_lock);
+
+        bdi_task_init(bdi, wb);
+
+        /*
+         * Clear pending bit and wakeup anybody waiting to tear us down
+         */
+        clear_bit(BDI_pending, &bdi->state);
+        smp_mb__after_clear_bit();
+        wake_up_bit(&bdi->state, BDI_pending);
+
+        ret = bdi_writeback_task(wb);
+
+        /*
+         * Remove us from the list
+         */
+        spin_lock(&bdi->wb_lock);
+        list_del_rcu(&wb->list);
+        spin_unlock(&bdi->wb_lock);
+
+        /*
+         * Flush any work that raced with us exiting. No new work
+         * will be added, since this bdi isn't discoverable anymore.
+         */
+        if (!list_empty(&bdi->work_list))
+                wb_do_writeback(wb, 1);
+
+        wb->task = NULL;
+        return ret;
+}
+
+int bdi_has_dirty_io(struct backing_dev_info *bdi)
+{
+        return wb_has_dirty_io(&bdi->wb);
+}
+
+static void bdi_flush_io(struct backing_dev_info *bdi)
+{
+        struct writeback_control wbc = {
+                .bdi                    = bdi,
+                .sync_mode              = WB_SYNC_NONE,
+                .older_than_this        = NULL,
+                .range_cyclic           = 1,
+                .nr_to_write            = 1024,
+        };
+
+        writeback_inodes_wbc(&wbc);
+}
+
+/*
+ * kupdated() used to do this. We cannot do it from the bdi_forker_task()
+ * or we risk deadlocking on ->s_umount. The longer term solution would be
+ * to implement sync_supers_bdi() or similar and simply do it from the
+ * bdi writeback tasks individually.
+ */
+static int bdi_sync_supers(void *unused)
+{
+        set_user_nice(current, 0);
+
+        while (!kthread_should_stop()) {
+                set_current_state(TASK_INTERRUPTIBLE);
+                schedule();
+
+                /*
+                 * Do this periodically, like kupdated() did before.
+                 */
+                sync_supers();
+        }
+
+        return 0;
+}
+
+static void arm_supers_timer(void)
+{
+        unsigned long next;
+
+        next = msecs_to_jiffies(dirty_writeback_interval * 10) + jiffies;
+        mod_timer(&sync_supers_timer, round_jiffies_up(next));
+}
+
+static void sync_supers_timer_fn(unsigned long unused)
+{
+        wake_up_process(sync_supers_tsk);
+        arm_supers_timer();
+}
+
+static int bdi_forker_task(void *ptr)
+{
+        struct bdi_writeback *me = ptr;
+
+        bdi_task_init(me->bdi, me);
+
+        for (;;) {
+                struct backing_dev_info *bdi, *tmp;
+                struct bdi_writeback *wb;
+
+                /*
+                 * Temporary measure, we want to make sure we don't see
+                 * dirty data on the default backing_dev_info
+                 */
+                if (wb_has_dirty_io(me) || !list_empty(&me->bdi->work_list))
+                        wb_do_writeback(me, 0);
+
+                spin_lock_bh(&bdi_lock);
+
+                /*
+                 * Check if any existing bdi's have dirty data without
+                 * a thread registered. If so, set that up.
+                 */
+                list_for_each_entry_safe(bdi, tmp, &bdi_list, bdi_list) {
+                        if (bdi->wb.task)
+                                continue;
+                        if (list_empty(&bdi->work_list) &&
+                            !bdi_has_dirty_io(bdi))
+                                continue;
+
+                        bdi_add_default_flusher_task(bdi);
+                }
+
+                set_current_state(TASK_INTERRUPTIBLE);
+
+                if (list_empty(&bdi_pending_list)) {
+                        unsigned long wait;
+
+                        spin_unlock_bh(&bdi_lock);
+                        wait = msecs_to_jiffies(dirty_writeback_interval * 10);
+                        schedule_timeout(wait);
+                        try_to_freeze();
+                        continue;
+                }
+
+                __set_current_state(TASK_RUNNING);
+
+                /*
+                 * This is our real job - check for pending entries in
+                 * bdi_pending_list, and create the tasks that got added
+                 */
+                bdi = list_entry(bdi_pending_list.next, struct backing_dev_info,
+                                 bdi_list);
+                list_del_init(&bdi->bdi_list);
+                spin_unlock_bh(&bdi_lock);
+
+                wb = &bdi->wb;
+                wb->task = kthread_run(bdi_start_fn, wb, "flush-%s",
+                                        dev_name(bdi->dev));
+                /*
+                 * If task creation fails, then readd the bdi to
+                 * the pending list and force writeout of the bdi
+                 * from this forker thread. That will free some memory
+                 * and we can try again.
+                 */
+                if (IS_ERR(wb->task)) {
+                        wb->task = NULL;
+
+                        /*
+                         * Add this 'bdi' to the back, so we get
+                         * a chance to flush other bdi's to free
+                         * memory.
+                         */
+                        spin_lock_bh(&bdi_lock);
+                        list_add_tail(&bdi->bdi_list, &bdi_pending_list);
+                        spin_unlock_bh(&bdi_lock);
+
+                        bdi_flush_io(bdi);
+                }
+        }
+
+        return 0;
+}
+
+static void bdi_add_to_pending(struct rcu_head *head)
+{
+        struct backing_dev_info *bdi;
+
+        bdi = container_of(head, struct backing_dev_info, rcu_head);
+        INIT_LIST_HEAD(&bdi->bdi_list);
+
+        spin_lock(&bdi_lock);
+        list_add_tail(&bdi->bdi_list, &bdi_pending_list);
+        spin_unlock(&bdi_lock);
+
+        /*
+         * We are now on the pending list, wake up bdi_forker_task()
+         * to finish the job and add us back to the active bdi_list
+         */
+        wake_up_process(default_backing_dev_info.wb.task);
+}
+
+/*
+ * Add the default flusher task that gets created for any bdi
+ * that has dirty data pending writeout
+ */
+void static bdi_add_default_flusher_task(struct backing_dev_info *bdi)
+{
+        if (!bdi_cap_writeback_dirty(bdi))
+                return;
+
+        if (WARN_ON(!test_bit(BDI_registered, &bdi->state))) {
+                printk(KERN_ERR "bdi %p/%s is not registered!\n",
+                                                        bdi, bdi->name);
+                return;
+        }
+
+        /*
+         * Check with the helper whether to proceed adding a task. Will only
+         * abort if we two or more simultanous calls to
+         * bdi_add_default_flusher_task() occured, further additions will block
+         * waiting for previous additions to finish.
+         */
+        if (!test_and_set_bit(BDI_pending, &bdi->state)) {
+                list_del_rcu(&bdi->bdi_list);
+
+                /*
+                 * We must wait for the current RCU period to end before
+                 * moving to the pending list. So schedule that operation
+                 * from an RCU callback.
+                 */
+                call_rcu(&bdi->rcu_head, bdi_add_to_pending);
+        }
+}
+
+/*
+ * Remove bdi from bdi_list, and ensure that it is no longer visible
+ */
+static void bdi_remove_from_list(struct backing_dev_info *bdi)
+{
+        spin_lock_bh(&bdi_lock);
+        list_del_rcu(&bdi->bdi_list);
+        spin_unlock_bh(&bdi_lock);
+
+        synchronize_rcu();
+}
+
 int bdi_register(struct backing_dev_info *bdi, struct device *parent,
                 const char *fmt, ...)
 {
@@ -211,9 +543,33 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
                 goto exit;
         }
 
+        spin_lock_bh(&bdi_lock);
+        list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
+        spin_unlock_bh(&bdi_lock);
+
         bdi->dev = dev;
-        bdi_debug_register(bdi, dev_name(dev));
 
+        /*
+         * Just start the forker thread for our default backing_dev_info,
+         * and add other bdi's to the list. They will get a thread created
+         * on-demand when they need it.
+         */
+        if (bdi_cap_flush_forker(bdi)) {
+                struct bdi_writeback *wb = &bdi->wb;
+
+                wb->task = kthread_run(bdi_forker_task, wb, "bdi-%s",
+                                                dev_name(dev));
+                if (IS_ERR(wb->task)) {
+                        wb->task = NULL;
+                        ret = -ENOMEM;
+
+                        bdi_remove_from_list(bdi);
+                        goto exit;
+                }
+        }
+
+        bdi_debug_register(bdi, dev_name(dev));
+        set_bit(BDI_registered, &bdi->state);
 exit:
         return ret;
 }
@@ -225,9 +581,40 @@ int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
 }
 EXPORT_SYMBOL(bdi_register_dev);
 
+/*
+ * Remove bdi from the global list and shutdown any threads we have running
+ */
+static void bdi_wb_shutdown(struct backing_dev_info *bdi)
+{
+        struct bdi_writeback *wb;
+
+        if (!bdi_cap_writeback_dirty(bdi))
+                return;
+
+        /*
+         * If setup is pending, wait for that to complete first
+         */
+        wait_on_bit(&bdi->state, BDI_pending, bdi_sched_wait,
+                        TASK_UNINTERRUPTIBLE);
+
+        /*
+         * Make sure nobody finds us on the bdi_list anymore
+         */
+        bdi_remove_from_list(bdi);
+
+        /*
+         * Finally, kill the kernel threads. We don't need to be RCU
+         * safe anymore, since the bdi is gone from visibility.
+         */
+        list_for_each_entry(wb, &bdi->wb_list, list)
+                kthread_stop(wb->task);
+}
+
 void bdi_unregister(struct backing_dev_info *bdi)
 {
         if (bdi->dev) {
+                if (!bdi_cap_flush_forker(bdi))
+                        bdi_wb_shutdown(bdi);
                 bdi_debug_unregister(bdi);
                 device_unregister(bdi->dev);
                 bdi->dev = NULL;
@@ -237,14 +624,26 @@ EXPORT_SYMBOL(bdi_unregister);
 
 int bdi_init(struct backing_dev_info *bdi)
 {
-        int i;
-        int err;
+        int i, err;
 
         bdi->dev = NULL;
 
         bdi->min_ratio = 0;
         bdi->max_ratio = 100;
         bdi->max_prop_frac = PROP_FRAC_BASE;
+        spin_lock_init(&bdi->wb_lock);
+        INIT_RCU_HEAD(&bdi->rcu_head);
+        INIT_LIST_HEAD(&bdi->bdi_list);
+        INIT_LIST_HEAD(&bdi->wb_list);
+        INIT_LIST_HEAD(&bdi->work_list);
+
+        bdi_wb_init(&bdi->wb, bdi);
+
+        /*
+         * Just one thread support for now, hard code mask and count
+         */
+        bdi->wb_mask = 1;
+        bdi->wb_cnt = 1;
 
         for (i = 0; i < NR_BDI_STAT_ITEMS; i++) {
                 err = percpu_counter_init(&bdi->bdi_stat[i], 0);
@@ -269,6 +668,20 @@ void bdi_destroy(struct backing_dev_info *bdi)
 {
         int i;
 
+        /*
+         * Splice our entries to the default_backing_dev_info, if this
+         * bdi disappears
+         */
+        if (bdi_has_dirty_io(bdi)) {
+                struct bdi_writeback *dst = &default_backing_dev_info.wb;
+
+                spin_lock(&inode_lock);
+                list_splice(&bdi->wb.b_dirty, &dst->b_dirty);
+                list_splice(&bdi->wb.b_io, &dst->b_io);
+                list_splice(&bdi->wb.b_more_io, &dst->b_more_io);
+                spin_unlock(&inode_lock);
+        }
+
         bdi_unregister(bdi);
 
         for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 701740c9e81b..555d5d2731c6 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -521,7 +521,11 @@ find_block:
                 region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
                                 start_off);
                 memset(region, 0, size);
-                kmemleak_alloc(region, size, 1, 0);
+                /*
+                 * The min_count is set to 0 so that bootmem allocated blocks
+                 * are never reported as leaks.
+                 */
+                kmemleak_alloc(region, size, 0, 0);
                 return region;
         }
 
diff --git a/mm/filemap.c b/mm/filemap.c
index ccea3b665c12..ef169f37156d 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -39,11 +39,10 @@
 /*
  * FIXME: remove all knowledge of the buffer layer from the core VM
  */
-#include <linux/buffer_head.h> /* for generic_osync_inode */
+#include <linux/buffer_head.h> /* for try_to_free_buffers */
 
 #include <asm/mman.h>
 
-
 /*
  * Shared mappings implemented 30.11.1994. It's not fully working yet,
  * though.
@@ -59,7 +58,7 @@
 /*
  * Lock ordering:
  *
- *  ->i_mmap_lock               (vmtruncate)
+ *  ->i_mmap_lock               (truncate_pagecache)
  *    ->private_lock            (__free_pte->__set_page_dirty_buffers)
  *      ->swap_lock             (exclusive_swap_page, others)
  *        ->mapping->tree_lock
@@ -105,6 +104,10 @@
  *
  *  ->task->proc_lock
  *    ->dcache_lock             (proc_pid_lookup)
+ *
+ *  (code doesn't rely on that order, so you could switch it around)
+ *  ->tasklist_lock             (memory_failure, collect_procs_ao)
+ *    ->i_mmap_lock
  */
 
 /*
@@ -120,6 +123,8 @@ void __remove_from_page_cache(struct page *page)
         page->mapping = NULL;
         mapping->nrpages--;
         __dec_zone_page_state(page, NR_FILE_PAGES);
+        if (PageSwapBacked(page))
+                __dec_zone_page_state(page, NR_SHMEM);
         BUG_ON(page_mapped(page));
 
         /*
@@ -307,68 +312,24 @@ int wait_on_page_writeback_range(struct address_space *mapping,
 }
 
 /**
- * sync_page_range - write and wait on all pages in the passed range
- * @inode:      target inode
- * @mapping:    target address_space
- * @pos:        beginning offset in pages to write
- * @count:      number of bytes to write
- *
- * Write and wait upon all the pages in the passed range.  This is a "data
- * integrity" operation.  It waits upon in-flight writeout before starting and
- * waiting upon new writeout.  If there was an IO error, return it.
+ * filemap_fdatawait_range - wait for all under-writeback pages to complete in a given range
+ * @mapping: address space structure to wait for
+ * @start:      offset in bytes where the range starts
+ * @end:        offset in bytes where the range ends (inclusive)
  *
- * We need to re-take i_mutex during the generic_osync_inode list walk because
- * it is otherwise livelockable.
- */
-int sync_page_range(struct inode *inode, struct address_space *mapping,
-                        loff_t pos, loff_t count)
-{
-        pgoff_t start = pos >> PAGE_CACHE_SHIFT;
-        pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
-        int ret;
-
-        if (!mapping_cap_writeback_dirty(mapping) || !count)
-                return 0;
-        ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
-        if (ret == 0) {
-                mutex_lock(&inode->i_mutex);
-                ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
-                mutex_unlock(&inode->i_mutex);
-        }
-        if (ret == 0)
-                ret = wait_on_page_writeback_range(mapping, start, end);
-        return ret;
-}
-EXPORT_SYMBOL(sync_page_range);
-
-/**
- * sync_page_range_nolock - write & wait on all pages in the passed range without locking
- * @inode:      target inode
- * @mapping:    target address_space
- * @pos:        beginning offset in pages to write
- * @count:      number of bytes to write
+ * Walk the list of under-writeback pages of the given address space
+ * in the given range and wait for all of them.
  *
- * Note: Holding i_mutex across sync_page_range_nolock() is not a good idea
- * as it forces O_SYNC writers to different parts of the same file
- * to be serialised right until io completion.
+ * This is just a simple wrapper so that callers don't have to convert offsets
+ * to page indexes themselves
  */
-int sync_page_range_nolock(struct inode *inode, struct address_space *mapping,
-                           loff_t pos, loff_t count)
+int filemap_fdatawait_range(struct address_space *mapping, loff_t start,
+                            loff_t end)
 {
-        pgoff_t start = pos >> PAGE_CACHE_SHIFT;
-        pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
-        int ret;
-
-        if (!mapping_cap_writeback_dirty(mapping) || !count)
-                return 0;
-        ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
-        if (ret == 0)
-                ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
-        if (ret == 0)
-                ret = wait_on_page_writeback_range(mapping, start, end);
-        return ret;
+        return wait_on_page_writeback_range(mapping, start >> PAGE_CACHE_SHIFT,
+                                            end >> PAGE_CACHE_SHIFT);
 }
-EXPORT_SYMBOL(sync_page_range_nolock);
+EXPORT_SYMBOL(filemap_fdatawait_range);
 
 /**
  * filemap_fdatawait - wait for all under-writeback pages to complete
@@ -476,6 +437,8 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
                 if (likely(!error)) {
                         mapping->nrpages++;
                         __inc_zone_page_state(page, NR_FILE_PAGES);
+                        if (PageSwapBacked(page))
+                                __inc_zone_page_state(page, NR_SHMEM);
                         spin_unlock_irq(&mapping->tree_lock);
                 } else {
                         page->mapping = NULL;
@@ -1648,7 +1611,7 @@ page_not_uptodate:
 }
 EXPORT_SYMBOL(filemap_fault);
 
-struct vm_operations_struct generic_file_vm_ops = {
+const struct vm_operations_struct generic_file_vm_ops = {
         .fault          = filemap_fault,
 };
 
@@ -2167,20 +2130,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
                 }
                 *ppos = end;
         }
-
-        /*
-         * Sync the fs metadata but not the minor inode changes and
-         * of course not the data as we did direct DMA for the IO.
-         * i_mutex is held, which protects generic_osync_inode() from
-         * livelocking.  AIO O_DIRECT ops attempt to sync metadata here.
-         */
 out:
-        if ((written >= 0 || written == -EIOCBQUEUED) &&
-            ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
-                int err = generic_osync_inode(inode, mapping, OSYNC_METADATA);
-                if (err < 0)
-                        written = err;
-        }
         return written;
 }
 EXPORT_SYMBOL(generic_file_direct_write);
@@ -2312,8 +2262,6 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
-        const struct address_space_operations *a_ops = mapping->a_ops;
-        struct inode *inode = mapping->host;
         ssize_t status;
         struct iov_iter i;
 
@@ -2323,16 +2271,6 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
         if (likely(status >= 0)) {
                 written += status;
                 *ppos = pos + status;
-
-                /*
-                 * For now, when the user asks for O_SYNC, we'll actually give
-                 * O_DSYNC
-                 */
-                if (unlikely((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
-                        if (!a_ops->writepage || !is_sync_kiocb(iocb))
-                                status = generic_osync_inode(inode, mapping,
-                                                OSYNC_METADATA|OSYNC_DATA);
-                }
         }
         
         /*
@@ -2348,9 +2286,27 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 }
 EXPORT_SYMBOL(generic_file_buffered_write);
 
-static ssize_t
-__generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
-                                unsigned long nr_segs, loff_t *ppos)
+/**
+ * __generic_file_aio_write - write data to a file
+ * @iocb:       IO state structure (file, offset, etc.)
+ * @iov:        vector with data to write
+ * @nr_segs:    number of segments in the vector
+ * @ppos:       position where to write
+ *
+ * This function does all the work needed for actually writing data to a
+ * file. It does all basic checks, removes SUID from the file, updates
+ * modification times and calls proper subroutines depending on whether we
+ * do direct IO or a standard buffered write.
+ *
+ * It expects i_mutex to be grabbed unless we work on a block device or similar
+ * object which does not need locking at all.
+ *
+ * This function does *not* take care of syncing data in case of O_SYNC write.
+ * A caller has to handle it. This is mainly due to the fact that we want to
+ * avoid syncing under i_mutex.
+ */
+ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+                                 unsigned long nr_segs, loff_t *ppos)
 {
         struct file *file = iocb->ki_filp;
         struct address_space * mapping = file->f_mapping;
@@ -2447,51 +2403,37 @@ out:
         current->backing_dev_info = NULL;
         return written ? written : err;
 }
+EXPORT_SYMBOL(__generic_file_aio_write);
 
-ssize_t generic_file_aio_write_nolock(struct kiocb *iocb,
-                const struct iovec *iov, unsigned long nr_segs, loff_t pos)
-{
-        struct file *file = iocb->ki_filp;
-        struct address_space *mapping = file->f_mapping;
-        struct inode *inode = mapping->host;
-        ssize_t ret;
-
-        BUG_ON(iocb->ki_pos != pos);
-
-        ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs,
-                        &iocb->ki_pos);
-
-        if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
-                ssize_t err;
-
-                err = sync_page_range_nolock(inode, mapping, pos, ret);
-                if (err < 0)
-                        ret = err;
-        }
-        return ret;
-}
-EXPORT_SYMBOL(generic_file_aio_write_nolock);
-
+/**
+ * generic_file_aio_write - write data to a file
+ * @iocb:       IO state structure
+ * @iov:        vector with data to write
+ * @nr_segs:    number of segments in the vector
+ * @pos:        position in file where to write
+ *
+ * This is a wrapper around __generic_file_aio_write() to be used by most
+ * filesystems. It takes care of syncing the file in case of O_SYNC file
+ * and acquires i_mutex as needed.
+ */
 ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
                 unsigned long nr_segs, loff_t pos)
 {
         struct file *file = iocb->ki_filp;
-        struct address_space *mapping = file->f_mapping;
-        struct inode *inode = mapping->host;
+        struct inode *inode = file->f_mapping->host;
         ssize_t ret;
 
         BUG_ON(iocb->ki_pos != pos);
 
         mutex_lock(&inode->i_mutex);
-        ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs,
-                        &iocb->ki_pos);
+        ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
         mutex_unlock(&inode->i_mutex);
 
-        if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+        if (ret > 0 || ret == -EIOCBQUEUED) {
                 ssize_t err;
 
-                err = sync_page_range(inode, mapping, pos, ret);
-                if (err < 0)
+                err = generic_write_sync(file, pos, ret);
+                if (err < 0 && ret > 0)
                         ret = err;
         }
         return ret;
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 427dfe3ce78c..1888b2d71bb8 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -296,7 +296,7 @@ out:
         }
 }
 
-static struct vm_operations_struct xip_file_vm_ops = {
+static const struct vm_operations_struct xip_file_vm_ops = {
         .fault  = xip_file_fault,
 };
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index cafdcee154e8..5d7601b02874 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -234,6 +234,7 @@ unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
 
         return 1UL << (hstate->order + PAGE_SHIFT);
 }
+EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
 
 /*
  * Return the page size being used by the MMU to back a VMA. In the majority
@@ -455,24 +456,6 @@ static void enqueue_huge_page(struct hstate *h, struct page *page)
         h->free_huge_pages_node[nid]++;
 }
 
-static struct page *dequeue_huge_page(struct hstate *h)
-{
-        int nid;
-        struct page *page = NULL;
-
-        for (nid = 0; nid < MAX_NUMNODES; ++nid) {
-                if (!list_empty(&h->hugepage_freelists[nid])) {
-                        page = list_entry(h->hugepage_freelists[nid].next,
-                                          struct page, lru);
-                        list_del(&page->lru);
-                        h->free_huge_pages--;
-                        h->free_huge_pages_node[nid]--;
-                        break;
-                }
-        }
-        return page;
-}
-
 static struct page *dequeue_huge_page_vma(struct hstate *h,
                                 struct vm_area_struct *vma,
                                 unsigned long address, int avoid_reserve)
@@ -640,7 +623,7 @@ static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
 
 /*
  * Use a helper variable to find the next node and then
- * copy it back to hugetlb_next_nid afterwards:
+ * copy it back to next_nid_to_alloc afterwards:
  * otherwise there's a window in which a racer might
  * pass invalid nid MAX_NUMNODES to alloc_pages_exact_node.
  * But we don't need to use a spin_lock here: it really
@@ -649,13 +632,13 @@ static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
  * if we just successfully allocated a hugepage so that
  * the next caller gets hugepages on the next node.
  */
-static int hstate_next_node(struct hstate *h)
+static int hstate_next_node_to_alloc(struct hstate *h)
 {
         int next_nid;
-        next_nid = next_node(h->hugetlb_next_nid, node_online_map);
+        next_nid = next_node(h->next_nid_to_alloc, node_online_map);
         if (next_nid == MAX_NUMNODES)
                 next_nid = first_node(node_online_map);
-        h->hugetlb_next_nid = next_nid;
+        h->next_nid_to_alloc = next_nid;
         return next_nid;
 }
 
@@ -666,14 +649,15 @@ static int alloc_fresh_huge_page(struct hstate *h)
         int next_nid;
         int ret = 0;
 
-        start_nid = h->hugetlb_next_nid;
+        start_nid = h->next_nid_to_alloc;
+        next_nid = start_nid;
 
         do {
-                page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid);
+                page = alloc_fresh_huge_page_node(h, next_nid);
                 if (page)
                         ret = 1;
-                next_nid = hstate_next_node(h);
-        } while (!page && h->hugetlb_next_nid != start_nid);
+                next_nid = hstate_next_node_to_alloc(h);
+        } while (!page && next_nid != start_nid);
 
         if (ret)
                 count_vm_event(HTLB_BUDDY_PGALLOC);
@@ -683,6 +667,61 @@ static int alloc_fresh_huge_page(struct hstate *h)
         return ret;
 }
 
+/*
+ * helper for free_pool_huge_page() - find next node
+ * from which to free a huge page
+ */
+static int hstate_next_node_to_free(struct hstate *h)
+{
+        int next_nid;
+        next_nid = next_node(h->next_nid_to_free, node_online_map);
+        if (next_nid == MAX_NUMNODES)
+                next_nid = first_node(node_online_map);
+        h->next_nid_to_free = next_nid;
+        return next_nid;
+}
+
+/*
+ * Free huge page from pool from next node to free.
+ * Attempt to keep persistent huge pages more or less
+ * balanced over allowed nodes.
+ * Called with hugetlb_lock locked.
+ */
+static int free_pool_huge_page(struct hstate *h, bool acct_surplus)
+{
+        int start_nid;
+        int next_nid;
+        int ret = 0;
+
+        start_nid = h->next_nid_to_free;
+        next_nid = start_nid;
+
+        do {
+                /*
+                 * If we're returning unused surplus pages, only examine
+                 * nodes with surplus pages.
+                 */
+                if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
+                    !list_empty(&h->hugepage_freelists[next_nid])) {
+                        struct page *page =
+                                list_entry(h->hugepage_freelists[next_nid].next,
+                                          struct page, lru);
+                        list_del(&page->lru);
+                        h->free_huge_pages--;
+                        h->free_huge_pages_node[next_nid]--;
+                        if (acct_surplus) {
+                                h->surplus_huge_pages--;
+                                h->surplus_huge_pages_node[next_nid]--;
+                        }
+                        update_and_free_page(h, page);
+                        ret = 1;
+                }
+                next_nid = hstate_next_node_to_free(h);
+        } while (!ret && next_nid != start_nid);
+
+        return ret;
+}
+
 static struct page *alloc_buddy_huge_page(struct hstate *h,
                         struct vm_area_struct *vma, unsigned long address)
 {
@@ -854,22 +893,13 @@ free:
  * When releasing a hugetlb pool reservation, any surplus pages that were
  * allocated to satisfy the reservation must be explicitly freed if they were
  * never used.
+ * Called with hugetlb_lock held.
  */
 static void return_unused_surplus_pages(struct hstate *h,
                                         unsigned long unused_resv_pages)
 {
-        static int nid = -1;
-        struct page *page;
         unsigned long nr_pages;
 
-        /*
-         * We want to release as many surplus pages as possible, spread
-         * evenly across all nodes. Iterate across all nodes until we
-         * can no longer free unreserved surplus pages. This occurs when
-         * the nodes with surplus pages have no free pages.
-         */
-        unsigned long remaining_iterations = nr_online_nodes;
-
         /* Uncommit the reservation */
         h->resv_huge_pages -= unused_resv_pages;
 
@@ -879,26 +909,17 @@ static void return_unused_surplus_pages(struct hstate *h,
 
         nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
 
-        while (remaining_iterations-- && nr_pages) {
-                nid = next_node(nid, node_online_map);
-                if (nid == MAX_NUMNODES)
-                        nid = first_node(node_online_map);
-
-                if (!h->surplus_huge_pages_node[nid])
-                        continue;
-
-                if (!list_empty(&h->hugepage_freelists[nid])) {
-                        page = list_entry(h->hugepage_freelists[nid].next,
-                                          struct page, lru);
-                        list_del(&page->lru);
-                        update_and_free_page(h, page);
-                        h->free_huge_pages--;
-                        h->free_huge_pages_node[nid]--;
-                        h->surplus_huge_pages--;
-                        h->surplus_huge_pages_node[nid]--;
-                        nr_pages--;
-                        remaining_iterations = nr_online_nodes;
-                }
+        /*
+         * We want to release as many surplus pages as possible, spread
+         * evenly across all nodes. Iterate across all nodes until we
+         * can no longer free unreserved surplus pages. This occurs when
+         * the nodes with surplus pages have no free pages.
+         * free_pool_huge_page() will balance the the frees across the
+         * on-line nodes for us and will handle the hstate accounting.
+         */
+        while (nr_pages--) {
+                if (!free_pool_huge_page(h, 1))
+                        break;
         }
 }
 
@@ -1007,9 +1028,10 @@ int __weak alloc_bootmem_huge_page(struct hstate *h)
                 void *addr;
 
                 addr = __alloc_bootmem_node_nopanic(
-                                NODE_DATA(h->hugetlb_next_nid),
+                                NODE_DATA(h->next_nid_to_alloc),
                                 huge_page_size(h), huge_page_size(h), 0);
 
+                hstate_next_node_to_alloc(h);
                 if (addr) {
                         /*
                          * Use the beginning of the huge page to store the
@@ -1019,7 +1041,6 @@ int __weak alloc_bootmem_huge_page(struct hstate *h)
                         m = addr;
                         goto found;
                 }
-                hstate_next_node(h);
                 nr_nodes--;
         }
         return 0;
@@ -1140,31 +1161,43 @@ static inline void try_to_free_low(struct hstate *h, unsigned long count)
  */
 static int adjust_pool_surplus(struct hstate *h, int delta)
 {
-        static int prev_nid;
-        int nid = prev_nid;
+        int start_nid, next_nid;
         int ret = 0;
 
         VM_BUG_ON(delta != -1 && delta != 1);
-        do {
-                nid = next_node(nid, node_online_map);
-                if (nid == MAX_NUMNODES)
-                        nid = first_node(node_online_map);
 
-                /* To shrink on this node, there must be a surplus page */
-                if (delta < 0 && !h->surplus_huge_pages_node[nid])
-                        continue;
-                /* Surplus cannot exceed the total number of pages */
-                if (delta > 0 && h->surplus_huge_pages_node[nid] >=
+        if (delta < 0)
+                start_nid = h->next_nid_to_alloc;
+        else
+                start_nid = h->next_nid_to_free;
+        next_nid = start_nid;
+
+        do {
+                int nid = next_nid;
+                if (delta < 0)  {
+                        next_nid = hstate_next_node_to_alloc(h);
+                        /*
+                         * To shrink on this node, there must be a surplus page
+                         */
+                        if (!h->surplus_huge_pages_node[nid])
+                                continue;
+                }
+                if (delta > 0) {
+                        next_nid = hstate_next_node_to_free(h);
+                        /*
+                         * Surplus cannot exceed the total number of pages
+                         */
+                        if (h->surplus_huge_pages_node[nid] >=
                                                 h->nr_huge_pages_node[nid])
-                        continue;
+                                continue;
+                }
 
                 h->surplus_huge_pages += delta;
                 h->surplus_huge_pages_node[nid] += delta;
                 ret = 1;
                 break;
-        } while (nid != prev_nid);
+        } while (next_nid != start_nid);
 
-        prev_nid = nid;
         return ret;
 }
 
@@ -1226,10 +1259,8 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
         min_count = max(count, min_count);
         try_to_free_low(h, min_count);
         while (min_count < persistent_huge_pages(h)) {
-                struct page *page = dequeue_huge_page(h);
-                if (!page)
+                if (!free_pool_huge_page(h, 0))
                         break;
-                update_and_free_page(h, page);
         }
         while (count < persistent_huge_pages(h)) {
                 if (!adjust_pool_surplus(h, 1))
@@ -1441,7 +1472,8 @@ void __init hugetlb_add_hstate(unsigned order)
         h->free_huge_pages = 0;
         for (i = 0; i < MAX_NUMNODES; ++i)
                 INIT_LIST_HEAD(&h->hugepage_freelists[i]);
-        h->hugetlb_next_nid = first_node(node_online_map);
+        h->next_nid_to_alloc = first_node(node_online_map);
+        h->next_nid_to_free = first_node(node_online_map);
         snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
                                         huge_page_size(h)/1024);
 
@@ -1505,7 +1537,7 @@ static unsigned int cpuset_mems_nr(unsigned int *array)
 
 #ifdef CONFIG_SYSCTL
 int hugetlb_sysctl_handler(struct ctl_table *table, int write,
-                           struct file *file, void __user *buffer,
+                           void __user *buffer,
                            size_t *length, loff_t *ppos)
 {
         struct hstate *h = &default_hstate;
@@ -1516,7 +1548,7 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write,
 
         table->data = &tmp;
         table->maxlen = sizeof(unsigned long);
-        proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+        proc_doulongvec_minmax(table, write, buffer, length, ppos);
 
         if (write)
                 h->max_huge_pages = set_max_huge_pages(h, tmp);
@@ -1525,10 +1557,10 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write,
 }
 
 int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
-                        struct file *file, void __user *buffer,
+                        void __user *buffer,
                         size_t *length, loff_t *ppos)
 {
-        proc_dointvec(table, write, file, buffer, length, ppos);
+        proc_dointvec(table, write, buffer, length, ppos);
         if (hugepages_treat_as_movable)
                 htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
         else
@@ -1537,7 +1569,7 @@ int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
 }
 
 int hugetlb_overcommit_handler(struct ctl_table *table, int write,
-                        struct file *file, void __user *buffer,
+                        void __user *buffer,
                         size_t *length, loff_t *ppos)
 {
         struct hstate *h = &default_hstate;
@@ -1548,7 +1580,7 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
 
         table->data = &tmp;
         table->maxlen = sizeof(unsigned long);
-        proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+        proc_doulongvec_minmax(table, write, buffer, length, ppos);
 
         if (write) {
                 spin_lock(&hugetlb_lock);
@@ -1689,7 +1721,7 @@ static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
         return 0;
 }
 
-struct vm_operations_struct hugetlb_vm_ops = {
+const struct vm_operations_struct hugetlb_vm_ops = {
         .fault = hugetlb_vm_op_fault,
         .open = hugetlb_vm_op_open,
         .close = hugetlb_vm_op_close,
@@ -1984,6 +2016,26 @@ static struct page *hugetlbfs_pagecache_page(struct hstate *h,
         return find_lock_page(mapping, idx);
 }
 
+/*
+ * Return whether there is a pagecache page to back given address within VMA.
+ * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
+ */
+static bool hugetlbfs_pagecache_present(struct hstate *h,
+                        struct vm_area_struct *vma, unsigned long address)
+{
+        struct address_space *mapping;
+        pgoff_t idx;
+        struct page *page;
+
+        mapping = vma->vm_file->f_mapping;
+        idx = vma_hugecache_offset(h, vma, address);
+
+        page = find_get_page(mapping, idx);
+        if (page)
+                put_page(page);
+        return page != NULL;
+}
+
 static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
                         unsigned long address, pte_t *ptep, unsigned int flags)
 {
@@ -2179,54 +2231,55 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address,
         return NULL;
 }
 
-static int huge_zeropage_ok(pte_t *ptep, int write, int shared)
-{
-        if (!ptep || write || shared)
-                return 0;
-        else
-                return huge_pte_none(huge_ptep_get(ptep));
-}
-
 int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
                         struct page **pages, struct vm_area_struct **vmas,
                         unsigned long *position, int *length, int i,
-                        int write)
+                        unsigned int flags)
 {
         unsigned long pfn_offset;
         unsigned long vaddr = *position;
         int remainder = *length;
         struct hstate *h = hstate_vma(vma);
-        int zeropage_ok = 0;
-        int shared = vma->vm_flags & VM_SHARED;
 
         spin_lock(&mm->page_table_lock);
         while (vaddr < vma->vm_end && remainder) {
                 pte_t *pte;
+                int absent;
                 struct page *page;
 
                 /*
                  * Some archs (sparc64, sh*) have multiple pte_ts to
-                 * each hugepage.  We have to make * sure we get the
+                 * each hugepage.  We have to make sure we get the
                  * first, for the page indexing below to work.
                  */
                 pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
-                if (huge_zeropage_ok(pte, write, shared))
-                        zeropage_ok = 1;
+                absent = !pte || huge_pte_none(huge_ptep_get(pte));
+
+                /*
+                 * When coredumping, it suits get_dump_page if we just return
+                 * an error where there's an empty slot with no huge pagecache
+                 * to back it.  This way, we avoid allocating a hugepage, and
+                 * the sparse dumpfile avoids allocating disk blocks, but its
+                 * huge holes still show up with zeroes where they need to be.
+                 */
+                if (absent && (flags & FOLL_DUMP) &&
+                    !hugetlbfs_pagecache_present(h, vma, vaddr)) {
+                        remainder = 0;
+                        break;
+                }
 
-                if (!pte ||
-                    (huge_pte_none(huge_ptep_get(pte)) && !zeropage_ok) ||
-                    (write && !pte_write(huge_ptep_get(pte)))) {
+                if (absent ||
+                    ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
                         int ret;
 
                         spin_unlock(&mm->page_table_lock);
-                        ret = hugetlb_fault(mm, vma, vaddr, write);
+                        ret = hugetlb_fault(mm, vma, vaddr,
+                                (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
                         spin_lock(&mm->page_table_lock);
                         if (!(ret & VM_FAULT_ERROR))
                                 continue;
 
                         remainder = 0;
-                        if (!i)
-                                i = -EFAULT;
                         break;
                 }
 
@@ -2234,10 +2287,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 page = pte_page(huge_ptep_get(pte));
 same_page:
                 if (pages) {
-                        if (zeropage_ok)
-                                pages[i] = ZERO_PAGE(0);
-                        else
-                                pages[i] = mem_map_offset(page, pfn_offset);
+                        pages[i] = mem_map_offset(page, pfn_offset);
                         get_page(pages[i]);
                 }
 
@@ -2261,7 +2311,7 @@ same_page:
         *length = remainder;
         *position = vaddr;
 
-        return i;
+        return i ? i : -EFAULT;
 }
 
 void hugetlb_change_protection(struct vm_area_struct *vma,
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
new file mode 100644
index 000000000000..e1d85137f086
--- /dev/null
+++ b/mm/hwpoison-inject.c
@@ -0,0 +1,41 @@
+/* Inject a hwpoison memory failure on a arbitary pfn */
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+static struct dentry *hwpoison_dir, *corrupt_pfn;
+
+static int hwpoison_inject(void *data, u64 val)
+{
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val);
+        return __memory_failure(val, 18, 0);
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
+
+static void pfn_inject_exit(void)
+{
+        if (hwpoison_dir)
+                debugfs_remove_recursive(hwpoison_dir);
+}
+
+static int pfn_inject_init(void)
+{
+        hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
+        if (hwpoison_dir == NULL)
+                return -ENOMEM;
+        corrupt_pfn = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
+                                          NULL, &hwpoison_fops);
+        if (corrupt_pfn == NULL) {
+                pfn_inject_exit();
+                return -ENOMEM;
+        }
+        return 0;
+}
+
+module_init(pfn_inject_init);
+module_exit(pfn_inject_exit);
+MODULE_LICENSE("GPL");
diff --git a/mm/internal.h b/mm/internal.h
index f290c4db528b..22ec8d2b0fb8 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -37,6 +37,8 @@ static inline void __put_page(struct page *page)
         atomic_dec(&page->_count);
 }
 
+extern unsigned long highest_memmap_pfn;
+
 /*
  * in mm/vmscan.c:
  */
@@ -46,7 +48,6 @@ extern void putback_lru_page(struct page *page);
 /*
  * in mm/page_alloc.c
  */
-extern unsigned long highest_memmap_pfn;
 extern void __free_pages_bootmem(struct page *page, unsigned int order);
 extern void prep_compound_page(struct page *page, unsigned long order);
 
@@ -250,13 +251,8 @@ static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 }
 #endif /* CONFIG_SPARSEMEM */
 
-#define GUP_FLAGS_WRITE                  0x1
-#define GUP_FLAGS_FORCE                  0x2
-#define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
-#define GUP_FLAGS_IGNORE_SIGKILL         0x8
-
 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-                     unsigned long start, int len, int flags,
+                     unsigned long start, int len, unsigned int foll_flags,
                      struct page **pages, struct vm_area_struct **vmas);
 
 #define ZONE_RECLAIM_NOSCAN     -2
diff --git a/mm/kmemleak-test.c b/mm/kmemleak-test.c
index d5292fc6f523..177a5169bbde 100644
--- a/mm/kmemleak-test.c
+++ b/mm/kmemleak-test.c
@@ -36,7 +36,7 @@ struct test_node {
 };
 
 static LIST_HEAD(test_list);
-static DEFINE_PER_CPU(void *, test_pointer);
+static DEFINE_PER_CPU(void *, kmemleak_test_pointer);
 
 /*
  * Some very simple testing. This function needs to be extended for
@@ -86,9 +86,9 @@ static int __init kmemleak_test_init(void)
         }
 
         for_each_possible_cpu(i) {
-                per_cpu(test_pointer, i) = kmalloc(129, GFP_KERNEL);
+                per_cpu(kmemleak_test_pointer, i) = kmalloc(129, GFP_KERNEL);
                 pr_info("kmemleak: kmalloc(129) = %p\n",
-                        per_cpu(test_pointer, i));
+                        per_cpu(kmemleak_test_pointer, i));
         }
 
         return 0;
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 487267310a84..8bf765c4f58d 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -92,11 +92,13 @@
 #include <linux/string.h>
 #include <linux/nodemask.h>
 #include <linux/mm.h>
+#include <linux/workqueue.h>
 
 #include <asm/sections.h>
 #include <asm/processor.h>
 #include <asm/atomic.h>
 
+#include <linux/kmemcheck.h>
 #include <linux/kmemleak.h>
 
 /*
@@ -107,6 +109,7 @@
 #define SECS_FIRST_SCAN         60      /* delay before the first scan */
 #define SECS_SCAN_WAIT          600     /* subsequent auto scanning delay */
 #define GRAY_LIST_PASSES        25      /* maximum number of gray list scans */
+#define MAX_SCAN_SIZE           4096    /* maximum size of a scanned block */
 
 #define BYTES_PER_POINTER       sizeof(void *)
 
@@ -120,6 +123,9 @@ struct kmemleak_scan_area {
         size_t length;
 };
 
+#define KMEMLEAK_GREY   0
+#define KMEMLEAK_BLACK  -1
+
 /*
  * Structure holding the metadata for each allocated memory block.
  * Modifications to such objects should be made while holding the
@@ -161,6 +167,15 @@ struct kmemleak_object {
 /* flag set on newly allocated objects */
 #define OBJECT_NEW              (1 << 3)
 
+/* number of bytes to print per line; must be 16 or 32 */
+#define HEX_ROW_SIZE            16
+/* number of bytes to print at a time (1, 2, 4, 8) */
+#define HEX_GROUP_SIZE          1
+/* include ASCII after the hex output */
+#define HEX_ASCII               1
+/* max number of lines to be printed */
+#define HEX_MAX_LINES           2
+
 /* the list of all allocated objects */
 static LIST_HEAD(object_list);
 /* the list of gray-colored objects (see color_gray comment below) */
@@ -228,11 +243,14 @@ struct early_log {
         int min_count;                  /* minimum reference count */
         unsigned long offset;           /* scan area offset */
         size_t length;                  /* scan area length */
+        unsigned long trace[MAX_TRACE]; /* stack trace */
+        unsigned int trace_len;         /* stack trace length */
 };
 
 /* early logging buffer and current position */
-static struct early_log early_log[CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE];
-static int crt_early_log;
+static struct early_log
+        early_log[CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE] __initdata;
+static int crt_early_log __initdata;
 
 static void kmemleak_disable(void);
 
@@ -255,6 +273,35 @@ static void kmemleak_disable(void);
 } while (0)
 
 /*
+ * Printing of the objects hex dump to the seq file. The number of lines to be
+ * printed is limited to HEX_MAX_LINES to prevent seq file spamming. The
+ * actual number of printed bytes depends on HEX_ROW_SIZE. It must be called
+ * with the object->lock held.
+ */
+static void hex_dump_object(struct seq_file *seq,
+                            struct kmemleak_object *object)
+{
+        const u8 *ptr = (const u8 *)object->pointer;
+        int i, len, remaining;
+        unsigned char linebuf[HEX_ROW_SIZE * 5];
+
+        /* limit the number of lines to HEX_MAX_LINES */
+        remaining = len =
+                min(object->size, (size_t)(HEX_MAX_LINES * HEX_ROW_SIZE));
+
+        seq_printf(seq, "  hex dump (first %d bytes):\n", len);
+        for (i = 0; i < len; i += HEX_ROW_SIZE) {
+                int linelen = min(remaining, HEX_ROW_SIZE);
+
+                remaining -= HEX_ROW_SIZE;
+                hex_dump_to_buffer(ptr + i, linelen, HEX_ROW_SIZE,
+                                   HEX_GROUP_SIZE, linebuf, sizeof(linebuf),
+                                   HEX_ASCII);
+                seq_printf(seq, "    %s\n", linebuf);
+        }
+}
+
+/*
  * Object colors, encoded with count and min_count:
  * - white - orphan object, not enough references to it (count < min_count)
  * - gray  - not orphan, not marked as false positive (min_count == 0) or
@@ -264,19 +311,21 @@ static void kmemleak_disable(void);
  * Newly created objects don't have any color assigned (object->count == -1)
  * before the next memory scan when they become white.
  */
-static int color_white(const struct kmemleak_object *object)
+static bool color_white(const struct kmemleak_object *object)
 {
-        return object->count != -1 && object->count < object->min_count;
+        return object->count != KMEMLEAK_BLACK &&
+                object->count < object->min_count;
 }
 
-static int color_gray(const struct kmemleak_object *object)
+static bool color_gray(const struct kmemleak_object *object)
 {
-        return object->min_count != -1 && object->count >= object->min_count;
+        return object->min_count != KMEMLEAK_BLACK &&
+                object->count >= object->min_count;
 }
 
-static int color_black(const struct kmemleak_object *object)
+static bool color_black(const struct kmemleak_object *object)
 {
-        return object->min_count == -1;
+        return object->min_count == KMEMLEAK_BLACK;
 }
 
 /*
@@ -284,7 +333,7 @@ static int color_black(const struct kmemleak_object *object)
  * not be deleted and have a minimum age to avoid false positives caused by
  * pointers temporarily stored in CPU registers.
  */
-static int unreferenced_object(struct kmemleak_object *object)
+static bool unreferenced_object(struct kmemleak_object *object)
 {
         return (object->flags & OBJECT_ALLOCATED) && color_white(object) &&
                 time_before_eq(object->jiffies + jiffies_min_age,
@@ -304,6 +353,7 @@ static void print_unreferenced(struct seq_file *seq,
                    object->pointer, object->size);
         seq_printf(seq, "  comm \"%s\", pid %d, jiffies %lu\n",
                    object->comm, object->pid, object->jiffies);
+        hex_dump_object(seq, object);
         seq_printf(seq, "  backtrace:\n");
 
         for (i = 0; i < object->trace_len; i++) {
@@ -330,6 +380,7 @@ static void dump_object_info(struct kmemleak_object *object)
                   object->comm, object->pid, object->jiffies);
         pr_notice("  min_count = %d\n", object->min_count);
         pr_notice("  count = %d\n", object->count);
+        pr_notice("  flags = 0x%lx\n", object->flags);
         pr_notice("  backtrace:\n");
         print_stack_trace(&trace, 4);
 }
@@ -434,21 +485,36 @@ static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
 }
 
 /*
+ * Save stack trace to the given array of MAX_TRACE size.
+ */
+static int __save_stack_trace(unsigned long *trace)
+{
+        struct stack_trace stack_trace;
+
+        stack_trace.max_entries = MAX_TRACE;
+        stack_trace.nr_entries = 0;
+        stack_trace.entries = trace;
+        stack_trace.skip = 2;
+        save_stack_trace(&stack_trace);
+
+        return stack_trace.nr_entries;
+}
+
+/*
  * Create the metadata (struct kmemleak_object) corresponding to an allocated
  * memory block and add it to the object_list and object_tree_root.
  */
-static void create_object(unsigned long ptr, size_t size, int min_count,
-                          gfp_t gfp)
+static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
+                                             int min_count, gfp_t gfp)
 {
         unsigned long flags;
         struct kmemleak_object *object;
         struct prio_tree_node *node;
-        struct stack_trace trace;
 
         object = kmem_cache_alloc(object_cache, gfp & GFP_KMEMLEAK_MASK);
         if (!object) {
                 kmemleak_stop("Cannot allocate a kmemleak_object structure\n");
-                return;
+                return NULL;
         }
 
         INIT_LIST_HEAD(&object->object_list);
@@ -482,18 +548,14 @@ static void create_object(unsigned long ptr, size_t size, int min_count,
         }
 
         /* kernel backtrace */
-        trace.max_entries = MAX_TRACE;
-        trace.nr_entries = 0;
-        trace.entries = object->trace;
-        trace.skip = 1;
-        save_stack_trace(&trace);
-        object->trace_len = trace.nr_entries;
+        object->trace_len = __save_stack_trace(object->trace);
 
         INIT_PRIO_TREE_NODE(&object->tree_node);
         object->tree_node.start = ptr;
         object->tree_node.last = ptr + size - 1;
 
         write_lock_irqsave(&kmemleak_lock, flags);
+
         min_addr = min(min_addr, ptr);
         max_addr = max(max_addr, ptr + size);
         node = prio_tree_insert(&object_tree_root, &object->tree_node);
@@ -504,20 +566,19 @@ static void create_object(unsigned long ptr, size_t size, int min_count,
          * random memory blocks.
          */
         if (node != &object->tree_node) {
-                unsigned long flags;
-
                 kmemleak_stop("Cannot insert 0x%lx into the object search tree "
                               "(already existing)\n", ptr);
                 object = lookup_object(ptr, 1);
-                spin_lock_irqsave(&object->lock, flags);
+                spin_lock(&object->lock);
                 dump_object_info(object);
-                spin_unlock_irqrestore(&object->lock, flags);
+                spin_unlock(&object->lock);
 
                 goto out;
         }
         list_add_tail_rcu(&object->object_list, &object_list);
 out:
         write_unlock_irqrestore(&kmemleak_lock, flags);
+        return object;
 }
 
 /*
@@ -604,46 +665,55 @@ static void delete_object_part(unsigned long ptr, size_t size)
 
         put_object(object);
 }
-/*
- * Make a object permanently as gray-colored so that it can no longer be
- * reported as a leak. This is used in general to mark a false positive.
- */
-static void make_gray_object(unsigned long ptr)
+
+static void __paint_it(struct kmemleak_object *object, int color)
+{
+        object->min_count = color;
+        if (color == KMEMLEAK_BLACK)
+                object->flags |= OBJECT_NO_SCAN;
+}
+
+static void paint_it(struct kmemleak_object *object, int color)
 {
         unsigned long flags;
+
+        spin_lock_irqsave(&object->lock, flags);
+        __paint_it(object, color);
+        spin_unlock_irqrestore(&object->lock, flags);
+}
+
+static void paint_ptr(unsigned long ptr, int color)
+{
         struct kmemleak_object *object;
 
         object = find_and_get_object(ptr, 0);
         if (!object) {
-                kmemleak_warn("Graying unknown object at 0x%08lx\n", ptr);
+                kmemleak_warn("Trying to color unknown object "
+                              "at 0x%08lx as %s\n", ptr,
+                              (color == KMEMLEAK_GREY) ? "Grey" :
+                              (color == KMEMLEAK_BLACK) ? "Black" : "Unknown");
                 return;
         }
-
-        spin_lock_irqsave(&object->lock, flags);
-        object->min_count = 0;
-        spin_unlock_irqrestore(&object->lock, flags);
+        paint_it(object, color);
         put_object(object);
 }
 
 /*
+ * Make a object permanently as gray-colored so that it can no longer be
+ * reported as a leak. This is used in general to mark a false positive.
+ */
+static void make_gray_object(unsigned long ptr)
+{
+        paint_ptr(ptr, KMEMLEAK_GREY);
+}
+
+/*
  * Mark the object as black-colored so that it is ignored from scans and
  * reporting.
  */
 static void make_black_object(unsigned long ptr)
 {
-        unsigned long flags;
-        struct kmemleak_object *object;
-
-        object = find_and_get_object(ptr, 0);
-        if (!object) {
-                kmemleak_warn("Blacking unknown object at 0x%08lx\n", ptr);
-                return;
-        }
-
-        spin_lock_irqsave(&object->lock, flags);
-        object->min_count = -1;
-        spin_unlock_irqrestore(&object->lock, flags);
-        put_object(object);
+        paint_ptr(ptr, KMEMLEAK_BLACK);
 }
 
 /*
@@ -715,14 +785,15 @@ static void object_no_scan(unsigned long ptr)
  * Log an early kmemleak_* call to the early_log buffer. These calls will be
  * processed later once kmemleak is fully initialized.
  */
-static void log_early(int op_type, const void *ptr, size_t size,
-                      int min_count, unsigned long offset, size_t length)
+static void __init log_early(int op_type, const void *ptr, size_t size,
+                             int min_count, unsigned long offset, size_t length)
 {
         unsigned long flags;
         struct early_log *log;
 
         if (crt_early_log >= ARRAY_SIZE(early_log)) {
-                pr_warning("Early log buffer exceeded\n");
+                pr_warning("Early log buffer exceeded, "
+                           "please increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n");
                 kmemleak_disable();
                 return;
         }
@@ -739,16 +810,48 @@ static void log_early(int op_type, const void *ptr, size_t size,
         log->min_count = min_count;
         log->offset = offset;
         log->length = length;
+        if (op_type == KMEMLEAK_ALLOC)
+                log->trace_len = __save_stack_trace(log->trace);
         crt_early_log++;
         local_irq_restore(flags);
 }
 
 /*
+ * Log an early allocated block and populate the stack trace.
+ */
+static void early_alloc(struct early_log *log)
+{
+        struct kmemleak_object *object;
+        unsigned long flags;
+        int i;
+
+        if (!atomic_read(&kmemleak_enabled) || !log->ptr || IS_ERR(log->ptr))
+                return;
+
+        /*
+         * RCU locking needed to ensure object is not freed via put_object().
+         */
+        rcu_read_lock();
+        object = create_object((unsigned long)log->ptr, log->size,
+                               log->min_count, GFP_ATOMIC);
+        if (!object)
+                goto out;
+        spin_lock_irqsave(&object->lock, flags);
+        for (i = 0; i < log->trace_len; i++)
+                object->trace[i] = log->trace[i];
+        object->trace_len = log->trace_len;
+        spin_unlock_irqrestore(&object->lock, flags);
+out:
+        rcu_read_unlock();
+}
+
+/*
  * Memory allocation function callback. This function is called from the
  * kernel allocators when a new block is allocated (kmem_cache_alloc, kmalloc,
  * vmalloc etc.).
  */
-void kmemleak_alloc(const void *ptr, size_t size, int min_count, gfp_t gfp)
+void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
+                          gfp_t gfp)
 {
         pr_debug("%s(0x%p, %zu, %d)\n", __func__, ptr, size, min_count);
 
@@ -763,7 +866,7 @@ EXPORT_SYMBOL_GPL(kmemleak_alloc);
  * Memory freeing function callback. This function is called from the kernel
  * allocators when a block is freed (kmem_cache_free, kfree, vfree etc.).
  */
-void kmemleak_free(const void *ptr)
+void __ref kmemleak_free(const void *ptr)
 {
         pr_debug("%s(0x%p)\n", __func__, ptr);
 
@@ -778,7 +881,7 @@ EXPORT_SYMBOL_GPL(kmemleak_free);
  * Partial memory freeing function callback. This function is usually called
  * from bootmem allocator when (part of) a memory block is freed.
  */
-void kmemleak_free_part(const void *ptr, size_t size)
+void __ref kmemleak_free_part(const void *ptr, size_t size)
 {
         pr_debug("%s(0x%p)\n", __func__, ptr);
 
@@ -793,7 +896,7 @@ EXPORT_SYMBOL_GPL(kmemleak_free_part);
  * Mark an already allocated memory block as a false positive. This will cause
  * the block to no longer be reported as leak and always be scanned.
  */
-void kmemleak_not_leak(const void *ptr)
+void __ref kmemleak_not_leak(const void *ptr)
 {
         pr_debug("%s(0x%p)\n", __func__, ptr);
 
@@ -809,7 +912,7 @@ EXPORT_SYMBOL(kmemleak_not_leak);
  * corresponding block is not a leak and does not contain any references to
  * other allocated memory blocks.
  */
-void kmemleak_ignore(const void *ptr)
+void __ref kmemleak_ignore(const void *ptr)
 {
         pr_debug("%s(0x%p)\n", __func__, ptr);
 
@@ -823,8 +926,8 @@ EXPORT_SYMBOL(kmemleak_ignore);
 /*
  * Limit the range to be scanned in an allocated memory block.
  */
-void kmemleak_scan_area(const void *ptr, unsigned long offset, size_t length,
-                        gfp_t gfp)
+void __ref kmemleak_scan_area(const void *ptr, unsigned long offset,
+                              size_t length, gfp_t gfp)
 {
         pr_debug("%s(0x%p)\n", __func__, ptr);
 
@@ -838,7 +941,7 @@ EXPORT_SYMBOL(kmemleak_scan_area);
 /*
  * Inform kmemleak not to scan the given memory block.
  */
-void kmemleak_no_scan(const void *ptr)
+void __ref kmemleak_no_scan(const void *ptr)
 {
         pr_debug("%s(0x%p)\n", __func__, ptr);
 
@@ -882,15 +985,22 @@ static void scan_block(void *_start, void *_end,
         unsigned long *end = _end - (BYTES_PER_POINTER - 1);
 
         for (ptr = start; ptr < end; ptr++) {
-                unsigned long flags;
-                unsigned long pointer = *ptr;
                 struct kmemleak_object *object;
+                unsigned long flags;
+                unsigned long pointer;
 
                 if (allow_resched)
                         cond_resched();
                 if (scan_should_stop())
                         break;
 
+                /* don't scan uninitialized memory */
+                if (!kmemcheck_is_obj_initialized((unsigned long)ptr,
+                                                  BYTES_PER_POINTER))
+                        continue;
+
+                pointer = *ptr;
+
                 object = find_and_get_object(pointer, 1);
                 if (!object)
                         continue;
@@ -949,10 +1059,21 @@ static void scan_object(struct kmemleak_object *object)
         if (!(object->flags & OBJECT_ALLOCATED))
                 /* already freed object */
                 goto out;
-        if (hlist_empty(&object->area_list))
-                scan_block((void *)object->pointer,
-                           (void *)(object->pointer + object->size), object, 0);
-        else
+        if (hlist_empty(&object->area_list)) {
+                void *start = (void *)object->pointer;
+                void *end = (void *)(object->pointer + object->size);
+
+                while (start < end && (object->flags & OBJECT_ALLOCATED) &&
+                       !(object->flags & OBJECT_NO_SCAN)) {
+                        scan_block(start, min(start + MAX_SCAN_SIZE, end),
+                                   object, 0);
+                        start += MAX_SCAN_SIZE;
+
+                        spin_unlock_irqrestore(&object->lock, flags);
+                        cond_resched();
+                        spin_lock_irqsave(&object->lock, flags);
+                }
+        } else
                 hlist_for_each_entry(area, elem, &object->area_list, node)
                         scan_block((void *)(object->pointer + area->offset),
                                    (void *)(object->pointer + area->offset
@@ -970,7 +1091,6 @@ static void kmemleak_scan(void)
 {
         unsigned long flags;
         struct kmemleak_object *object, *tmp;
-        struct task_struct *task;
         int i;
         int new_leaks = 0;
         int gray_list_pass = 0;
@@ -1037,15 +1157,16 @@ static void kmemleak_scan(void)
         }
 
         /*
-         * Scanning the task stacks may introduce false negatives and it is
-         * not enabled by default.
+         * Scanning the task stacks (may introduce false negatives).
          */
         if (kmemleak_stack_scan) {
+                struct task_struct *p, *g;
+
                 read_lock(&tasklist_lock);
-                for_each_process(task)
-                        scan_block(task_stack_page(task),
-                                   task_stack_page(task) + THREAD_SIZE,
-                                   NULL, 0);
+                do_each_thread(g, p) {
+                        scan_block(task_stack_page(p), task_stack_page(p) +
+                                   THREAD_SIZE, NULL, 0);
+                } while_each_thread(g, p);
                 read_unlock(&tasklist_lock);
         }
 
@@ -1170,7 +1291,7 @@ static int kmemleak_scan_thread(void *arg)
  * Start the automatic memory scanning thread. This function must be called
  * with the scan_mutex held.
  */
-void start_scan_thread(void)
+static void start_scan_thread(void)
 {
         if (scan_thread)
                 return;
@@ -1185,7 +1306,7 @@ void start_scan_thread(void)
  * Stop the automatic memory scanning thread. This function must be called
  * with the scan_mutex held.
  */
-void stop_scan_thread(void)
+static void stop_scan_thread(void)
 {
         if (scan_thread) {
                 kthread_stop(scan_thread);
@@ -1294,6 +1415,49 @@ static int kmemleak_release(struct inode *inode, struct file *file)
         return seq_release(inode, file);
 }
 
+static int dump_str_object_info(const char *str)
+{
+        unsigned long flags;
+        struct kmemleak_object *object;
+        unsigned long addr;
+
+        addr= simple_strtoul(str, NULL, 0);
+        object = find_and_get_object(addr, 0);
+        if (!object) {
+                pr_info("Unknown object at 0x%08lx\n", addr);
+                return -EINVAL;
+        }
+
+        spin_lock_irqsave(&object->lock, flags);
+        dump_object_info(object);
+        spin_unlock_irqrestore(&object->lock, flags);
+
+        put_object(object);
+        return 0;
+}
+
+/*
+ * We use grey instead of black to ensure we can do future scans on the same
+ * objects. If we did not do future scans these black objects could
+ * potentially contain references to newly allocated objects in the future and
+ * we'd end up with false positives.
+ */
+static void kmemleak_clear(void)
+{
+        struct kmemleak_object *object;
+        unsigned long flags;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(object, &object_list, object_list) {
+                spin_lock_irqsave(&object->lock, flags);
+                if ((object->flags & OBJECT_REPORTED) &&
+                    unreferenced_object(object))
+                        __paint_it(object, KMEMLEAK_GREY);
+                spin_unlock_irqrestore(&object->lock, flags);
+        }
+        rcu_read_unlock();
+}
+
 /*
  * File write operation to configure kmemleak at run-time. The following
  * commands can be written to the /sys/kernel/debug/kmemleak file:
@@ -1305,6 +1469,9 @@ static int kmemleak_release(struct inode *inode, struct file *file)
  *   scan=...   - set the automatic memory scanning period in seconds (0 to
  *                disable it)
  *   scan       - trigger a memory scan
+ *   clear      - mark all current reported unreferenced kmemleak objects as
+ *                grey to ignore printing them
+ *   dump=...   - dump information about the object found at the given address
  */
 static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
                               size_t size, loff_t *ppos)
@@ -1345,6 +1512,10 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
                 }
         } else if (strncmp(buf, "scan", 4) == 0)
                 kmemleak_scan();
+        else if (strncmp(buf, "clear", 5) == 0)
+                kmemleak_clear();
+        else if (strncmp(buf, "dump=", 5) == 0)
+                ret = dump_str_object_info(buf + 5);
         else
                 ret = -EINVAL;
 
@@ -1371,7 +1542,7 @@ static const struct file_operations kmemleak_fops = {
  * Perform the freeing of the kmemleak internal objects after waiting for any
  * current memory scan to complete.
  */
-static int kmemleak_cleanup_thread(void *arg)
+static void kmemleak_do_cleanup(struct work_struct *work)
 {
         struct kmemleak_object *object;
 
@@ -1383,22 +1554,9 @@ static int kmemleak_cleanup_thread(void *arg)
                 delete_object_full(object->pointer);
         rcu_read_unlock();
         mutex_unlock(&scan_mutex);
-
-        return 0;
 }
 
-/*
- * Start the clean-up thread.
- */
-static void kmemleak_cleanup(void)
-{
-        struct task_struct *cleanup_thread;
-
-        cleanup_thread = kthread_run(kmemleak_cleanup_thread, NULL,
-                                     "kmemleak-clean");
-        if (IS_ERR(cleanup_thread))
-                pr_warning("Failed to create the clean-up thread\n");
-}
+static DECLARE_WORK(cleanup_work, kmemleak_do_cleanup);
 
 /*
  * Disable kmemleak. No memory allocation/freeing will be traced once this
@@ -1416,7 +1574,7 @@ static void kmemleak_disable(void)
 
         /* check whether it is too early for a kernel thread */
         if (atomic_read(&kmemleak_initialized))
-                kmemleak_cleanup();
+                schedule_work(&cleanup_work);
 
         pr_info("Kernel memory leak detector disabled\n");
 }
@@ -1469,8 +1627,7 @@ void __init kmemleak_init(void)
 
                 switch (log->op_type) {
                 case KMEMLEAK_ALLOC:
-                        kmemleak_alloc(log->ptr, log->size, log->min_count,
-                                       GFP_KERNEL);
+                        early_alloc(log);
                         break;
                 case KMEMLEAK_FREE:
                         kmemleak_free(log->ptr);
@@ -1513,7 +1670,7 @@ static int __init kmemleak_late_init(void)
                  * after setting kmemleak_initialized and we may end up with
                  * two clean-up threads but serialized by scan_mutex.
                  */
-                kmemleak_cleanup();
+                schedule_work(&cleanup_work);
                 return -ENOMEM;
         }
 
diff --git a/mm/ksm.c b/mm/ksm.c
new file mode 100644
index 000000000000..bef1af4f77e3
--- /dev/null
+++ b/mm/ksm.c
@@ -0,0 +1,1709 @@
+/*
+ * Memory merging support.
+ *
+ * This code enables dynamic sharing of identical pages found in different
+ * memory areas, even if they are not shared by fork()
+ *
+ * Copyright (C) 2008-2009 Red Hat, Inc.
+ * Authors:
+ *      Izik Eidus
+ *      Andrea Arcangeli
+ *      Chris Wright
+ *      Hugh Dickins
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/mman.h>
+#include <linux/sched.h>
+#include <linux/rwsem.h>
+#include <linux/pagemap.h>
+#include <linux/rmap.h>
+#include <linux/spinlock.h>
+#include <linux/jhash.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/rbtree.h>
+#include <linux/mmu_notifier.h>
+#include <linux/swap.h>
+#include <linux/ksm.h>
+
+#include <asm/tlbflush.h>
+
+/*
+ * A few notes about the KSM scanning process,
+ * to make it easier to understand the data structures below:
+ *
+ * In order to reduce excessive scanning, KSM sorts the memory pages by their
+ * contents into a data structure that holds pointers to the pages' locations.
+ *
+ * Since the contents of the pages may change at any moment, KSM cannot just
+ * insert the pages into a normal sorted tree and expect it to find anything.
+ * Therefore KSM uses two data structures - the stable and the unstable tree.
+ *
+ * The stable tree holds pointers to all the merged pages (ksm pages), sorted
+ * by their contents.  Because each such page is write-protected, searching on
+ * this tree is fully assured to be working (except when pages are unmapped),
+ * and therefore this tree is called the stable tree.
+ *
+ * In addition to the stable tree, KSM uses a second data structure called the
+ * unstable tree: this tree holds pointers to pages which have been found to
+ * be "unchanged for a period of time".  The unstable tree sorts these pages
+ * by their contents, but since they are not write-protected, KSM cannot rely
+ * upon the unstable tree to work correctly - the unstable tree is liable to
+ * be corrupted as its contents are modified, and so it is called unstable.
+ *
+ * KSM solves this problem by several techniques:
+ *
+ * 1) The unstable tree is flushed every time KSM completes scanning all
+ *    memory areas, and then the tree is rebuilt again from the beginning.
+ * 2) KSM will only insert into the unstable tree, pages whose hash value
+ *    has not changed since the previous scan of all memory areas.
+ * 3) The unstable tree is a RedBlack Tree - so its balancing is based on the
+ *    colors of the nodes and not on their contents, assuring that even when
+ *    the tree gets "corrupted" it won't get out of balance, so scanning time
+ *    remains the same (also, searching and inserting nodes in an rbtree uses
+ *    the same algorithm, so we have no overhead when we flush and rebuild).
+ * 4) KSM never flushes the stable tree, which means that even if it were to
+ *    take 10 attempts to find a page in the unstable tree, once it is found,
+ *    it is secured in the stable tree.  (When we scan a new page, we first
+ *    compare it against the stable tree, and then against the unstable tree.)
+ */
+
+/**
+ * struct mm_slot - ksm information per mm that is being scanned
+ * @link: link to the mm_slots hash list
+ * @mm_list: link into the mm_slots list, rooted in ksm_mm_head
+ * @rmap_list: head for this mm_slot's list of rmap_items
+ * @mm: the mm that this information is valid for
+ */
+struct mm_slot {
+        struct hlist_node link;
+        struct list_head mm_list;
+        struct list_head rmap_list;
+        struct mm_struct *mm;
+};
+
+/**
+ * struct ksm_scan - cursor for scanning
+ * @mm_slot: the current mm_slot we are scanning
+ * @address: the next address inside that to be scanned
+ * @rmap_item: the current rmap that we are scanning inside the rmap_list
+ * @seqnr: count of completed full scans (needed when removing unstable node)
+ *
+ * There is only the one ksm_scan instance of this cursor structure.
+ */
+struct ksm_scan {
+        struct mm_slot *mm_slot;
+        unsigned long address;
+        struct rmap_item *rmap_item;
+        unsigned long seqnr;
+};
+
+/**
+ * struct rmap_item - reverse mapping item for virtual addresses
+ * @link: link into mm_slot's rmap_list (rmap_list is per mm)
+ * @mm: the memory structure this rmap_item is pointing into
+ * @address: the virtual address this rmap_item tracks (+ flags in low bits)
+ * @oldchecksum: previous checksum of the page at that virtual address
+ * @node: rb_node of this rmap_item in either unstable or stable tree
+ * @next: next rmap_item hanging off the same node of the stable tree
+ * @prev: previous rmap_item hanging off the same node of the stable tree
+ */
+struct rmap_item {
+        struct list_head link;
+        struct mm_struct *mm;
+        unsigned long address;          /* + low bits used for flags below */
+        union {
+                unsigned int oldchecksum;               /* when unstable */
+                struct rmap_item *next;                 /* when stable */
+        };
+        union {
+                struct rb_node node;                    /* when tree node */
+                struct rmap_item *prev;                 /* in stable list */
+        };
+};
+
+#define SEQNR_MASK      0x0ff   /* low bits of unstable tree seqnr */
+#define NODE_FLAG       0x100   /* is a node of unstable or stable tree */
+#define STABLE_FLAG     0x200   /* is a node or list item of stable tree */
+
+/* The stable and unstable tree heads */
+static struct rb_root root_stable_tree = RB_ROOT;
+static struct rb_root root_unstable_tree = RB_ROOT;
+
+#define MM_SLOTS_HASH_HEADS 1024
+static struct hlist_head *mm_slots_hash;
+
+static struct mm_slot ksm_mm_head = {
+        .mm_list = LIST_HEAD_INIT(ksm_mm_head.mm_list),
+};
+static struct ksm_scan ksm_scan = {
+        .mm_slot = &ksm_mm_head,
+};
+
+static struct kmem_cache *rmap_item_cache;
+static struct kmem_cache *mm_slot_cache;
+
+/* The number of nodes in the stable tree */
+static unsigned long ksm_pages_shared;
+
+/* The number of page slots additionally sharing those nodes */
+static unsigned long ksm_pages_sharing;
+
+/* The number of nodes in the unstable tree */
+static unsigned long ksm_pages_unshared;
+
+/* The number of rmap_items in use: to calculate pages_volatile */
+static unsigned long ksm_rmap_items;
+
+/* Limit on the number of unswappable pages used */
+static unsigned long ksm_max_kernel_pages;
+
+/* Number of pages ksmd should scan in one batch */
+static unsigned int ksm_thread_pages_to_scan = 100;
+
+/* Milliseconds ksmd should sleep between batches */
+static unsigned int ksm_thread_sleep_millisecs = 20;
+
+#define KSM_RUN_STOP    0
+#define KSM_RUN_MERGE   1
+#define KSM_RUN_UNMERGE 2
+static unsigned int ksm_run = KSM_RUN_STOP;
+
+static DECLARE_WAIT_QUEUE_HEAD(ksm_thread_wait);
+static DEFINE_MUTEX(ksm_thread_mutex);
+static DEFINE_SPINLOCK(ksm_mmlist_lock);
+
+#define KSM_KMEM_CACHE(__struct, __flags) kmem_cache_create("ksm_"#__struct,\
+                sizeof(struct __struct), __alignof__(struct __struct),\
+                (__flags), NULL)
+
+static int __init ksm_slab_init(void)
+{
+        rmap_item_cache = KSM_KMEM_CACHE(rmap_item, 0);
+        if (!rmap_item_cache)
+                goto out;
+
+        mm_slot_cache = KSM_KMEM_CACHE(mm_slot, 0);
+        if (!mm_slot_cache)
+                goto out_free;
+
+        return 0;
+
+out_free:
+        kmem_cache_destroy(rmap_item_cache);
+out:
+        return -ENOMEM;
+}
+
+static void __init ksm_slab_free(void)
+{
+        kmem_cache_destroy(mm_slot_cache);
+        kmem_cache_destroy(rmap_item_cache);
+        mm_slot_cache = NULL;
+}
+
+static inline struct rmap_item *alloc_rmap_item(void)
+{
+        struct rmap_item *rmap_item;
+
+        rmap_item = kmem_cache_zalloc(rmap_item_cache, GFP_KERNEL);
+        if (rmap_item)
+                ksm_rmap_items++;
+        return rmap_item;
+}
+
+static inline void free_rmap_item(struct rmap_item *rmap_item)
+{
+        ksm_rmap_items--;
+        rmap_item->mm = NULL;   /* debug safety */
+        kmem_cache_free(rmap_item_cache, rmap_item);
+}
+
+static inline struct mm_slot *alloc_mm_slot(void)
+{
+        if (!mm_slot_cache)     /* initialization failed */
+                return NULL;
+        return kmem_cache_zalloc(mm_slot_cache, GFP_KERNEL);
+}
+
+static inline void free_mm_slot(struct mm_slot *mm_slot)
+{
+        kmem_cache_free(mm_slot_cache, mm_slot);
+}
+
+static int __init mm_slots_hash_init(void)
+{
+        mm_slots_hash = kzalloc(MM_SLOTS_HASH_HEADS * sizeof(struct hlist_head),
+                                GFP_KERNEL);
+        if (!mm_slots_hash)
+                return -ENOMEM;
+        return 0;
+}
+
+static void __init mm_slots_hash_free(void)
+{
+        kfree(mm_slots_hash);
+}
+
+static struct mm_slot *get_mm_slot(struct mm_struct *mm)
+{
+        struct mm_slot *mm_slot;
+        struct hlist_head *bucket;
+        struct hlist_node *node;
+
+        bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
+                                % MM_SLOTS_HASH_HEADS];
+        hlist_for_each_entry(mm_slot, node, bucket, link) {
+                if (mm == mm_slot->mm)
+                        return mm_slot;
+        }
+        return NULL;
+}
+
+static void insert_to_mm_slots_hash(struct mm_struct *mm,
+                                    struct mm_slot *mm_slot)
+{
+        struct hlist_head *bucket;
+
+        bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
+                                % MM_SLOTS_HASH_HEADS];
+        mm_slot->mm = mm;
+        INIT_LIST_HEAD(&mm_slot->rmap_list);
+        hlist_add_head(&mm_slot->link, bucket);
+}
+
+static inline int in_stable_tree(struct rmap_item *rmap_item)
+{
+        return rmap_item->address & STABLE_FLAG;
+}
+
+/*
+ * ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's
+ * page tables after it has passed through ksm_exit() - which, if necessary,
+ * takes mmap_sem briefly to serialize against them.  ksm_exit() does not set
+ * a special flag: they can just back out as soon as mm_users goes to zero.
+ * ksm_test_exit() is used throughout to make this test for exit: in some
+ * places for correctness, in some places just to avoid unnecessary work.
+ */
+static inline bool ksm_test_exit(struct mm_struct *mm)
+{
+        return atomic_read(&mm->mm_users) == 0;
+}
+
+/*
+ * We use break_ksm to break COW on a ksm page: it's a stripped down
+ *
+ *      if (get_user_pages(current, mm, addr, 1, 1, 1, &page, NULL) == 1)
+ *              put_page(page);
+ *
+ * but taking great care only to touch a ksm page, in a VM_MERGEABLE vma,
+ * in case the application has unmapped and remapped mm,addr meanwhile.
+ * Could a ksm page appear anywhere else?  Actually yes, in a VM_PFNMAP
+ * mmap of /dev/mem or /dev/kmem, where we would not want to touch it.
+ */
+static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
+{
+        struct page *page;
+        int ret = 0;
+
+        do {
+                cond_resched();
+                page = follow_page(vma, addr, FOLL_GET);
+                if (!page)
+                        break;
+                if (PageKsm(page))
+                        ret = handle_mm_fault(vma->vm_mm, vma, addr,
+                                                        FAULT_FLAG_WRITE);
+                else
+                        ret = VM_FAULT_WRITE;
+                put_page(page);
+        } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_OOM)));
+        /*
+         * We must loop because handle_mm_fault() may back out if there's
+         * any difficulty e.g. if pte accessed bit gets updated concurrently.
+         *
+         * VM_FAULT_WRITE is what we have been hoping for: it indicates that
+         * COW has been broken, even if the vma does not permit VM_WRITE;
+         * but note that a concurrent fault might break PageKsm for us.
+         *
+         * VM_FAULT_SIGBUS could occur if we race with truncation of the
+         * backing file, which also invalidates anonymous pages: that's
+         * okay, that truncation will have unmapped the PageKsm for us.
+         *
+         * VM_FAULT_OOM: at the time of writing (late July 2009), setting
+         * aside mem_cgroup limits, VM_FAULT_OOM would only be set if the
+         * current task has TIF_MEMDIE set, and will be OOM killed on return
+         * to user; and ksmd, having no mm, would never be chosen for that.
+         *
+         * But if the mm is in a limited mem_cgroup, then the fault may fail
+         * with VM_FAULT_OOM even if the current task is not TIF_MEMDIE; and
+         * even ksmd can fail in this way - though it's usually breaking ksm
+         * just to undo a merge it made a moment before, so unlikely to oom.
+         *
+         * That's a pity: we might therefore have more kernel pages allocated
+         * than we're counting as nodes in the stable tree; but ksm_do_scan
+         * will retry to break_cow on each pass, so should recover the page
+         * in due course.  The important thing is to not let VM_MERGEABLE
+         * be cleared while any such pages might remain in the area.
+         */
+        return (ret & VM_FAULT_OOM) ? -ENOMEM : 0;
+}
+
+static void break_cow(struct mm_struct *mm, unsigned long addr)
+{
+        struct vm_area_struct *vma;
+
+        down_read(&mm->mmap_sem);
+        if (ksm_test_exit(mm))
+                goto out;
+        vma = find_vma(mm, addr);
+        if (!vma || vma->vm_start > addr)
+                goto out;
+        if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+                goto out;
+        break_ksm(vma, addr);
+out:
+        up_read(&mm->mmap_sem);
+}
+
+static struct page *get_mergeable_page(struct rmap_item *rmap_item)
+{
+        struct mm_struct *mm = rmap_item->mm;
+        unsigned long addr = rmap_item->address;
+        struct vm_area_struct *vma;
+        struct page *page;
+
+        down_read(&mm->mmap_sem);
+        if (ksm_test_exit(mm))
+                goto out;
+        vma = find_vma(mm, addr);
+        if (!vma || vma->vm_start > addr)
+                goto out;
+        if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+                goto out;
+
+        page = follow_page(vma, addr, FOLL_GET);
+        if (!page)
+                goto out;
+        if (PageAnon(page)) {
+                flush_anon_page(vma, page, addr);
+                flush_dcache_page(page);
+        } else {
+                put_page(page);
+out:            page = NULL;
+        }
+        up_read(&mm->mmap_sem);
+        return page;
+}
+
+/*
+ * get_ksm_page: checks if the page at the virtual address in rmap_item
+ * is still PageKsm, in which case we can trust the content of the page,
+ * and it returns the gotten page; but NULL if the page has been zapped.
+ */
+static struct page *get_ksm_page(struct rmap_item *rmap_item)
+{
+        struct page *page;
+
+        page = get_mergeable_page(rmap_item);
+        if (page && !PageKsm(page)) {
+                put_page(page);
+                page = NULL;
+        }
+        return page;
+}
+
+/*
+ * Removing rmap_item from stable or unstable tree.
+ * This function will clean the information from the stable/unstable tree.
+ */
+static void remove_rmap_item_from_tree(struct rmap_item *rmap_item)
+{
+        if (in_stable_tree(rmap_item)) {
+                struct rmap_item *next_item = rmap_item->next;
+
+                if (rmap_item->address & NODE_FLAG) {
+                        if (next_item) {
+                                rb_replace_node(&rmap_item->node,
+                                                &next_item->node,
+                                                &root_stable_tree);
+                                next_item->address |= NODE_FLAG;
+                                ksm_pages_sharing--;
+                        } else {
+                                rb_erase(&rmap_item->node, &root_stable_tree);
+                                ksm_pages_shared--;
+                        }
+                } else {
+                        struct rmap_item *prev_item = rmap_item->prev;
+
+                        BUG_ON(prev_item->next != rmap_item);
+                        prev_item->next = next_item;
+                        if (next_item) {
+                                BUG_ON(next_item->prev != rmap_item);
+                                next_item->prev = rmap_item->prev;
+                        }
+                        ksm_pages_sharing--;
+                }
+
+                rmap_item->next = NULL;
+
+        } else if (rmap_item->address & NODE_FLAG) {
+                unsigned char age;
+                /*
+                 * Usually ksmd can and must skip the rb_erase, because
+                 * root_unstable_tree was already reset to RB_ROOT.
+                 * But be careful when an mm is exiting: do the rb_erase
+                 * if this rmap_item was inserted by this scan, rather
+                 * than left over from before.
+                 */
+                age = (unsigned char)(ksm_scan.seqnr - rmap_item->address);
+                BUG_ON(age > 1);
+                if (!age)
+                        rb_erase(&rmap_item->node, &root_unstable_tree);
+                ksm_pages_unshared--;
+        }
+
+        rmap_item->address &= PAGE_MASK;
+
+        cond_resched();         /* we're called from many long loops */
+}
+
+static void remove_trailing_rmap_items(struct mm_slot *mm_slot,
+                                       struct list_head *cur)
+{
+        struct rmap_item *rmap_item;
+
+        while (cur != &mm_slot->rmap_list) {
+                rmap_item = list_entry(cur, struct rmap_item, link);
+                cur = cur->next;
+                remove_rmap_item_from_tree(rmap_item);
+                list_del(&rmap_item->link);
+                free_rmap_item(rmap_item);
+        }
+}
+
+/*
+ * Though it's very tempting to unmerge in_stable_tree(rmap_item)s rather
+ * than check every pte of a given vma, the locking doesn't quite work for
+ * that - an rmap_item is assigned to the stable tree after inserting ksm
+ * page and upping mmap_sem.  Nor does it fit with the way we skip dup'ing
+ * rmap_items from parent to child at fork time (so as not to waste time
+ * if exit comes before the next scan reaches it).
+ *
+ * Similarly, although we'd like to remove rmap_items (so updating counts
+ * and freeing memory) when unmerging an area, it's easier to leave that
+ * to the next pass of ksmd - consider, for example, how ksmd might be
+ * in cmp_and_merge_page on one of the rmap_items we would be removing.
+ */
+static int unmerge_ksm_pages(struct vm_area_struct *vma,
+                             unsigned long start, unsigned long end)
+{
+        unsigned long addr;
+        int err = 0;
+
+        for (addr = start; addr < end && !err; addr += PAGE_SIZE) {
+                if (ksm_test_exit(vma->vm_mm))
+                        break;
+                if (signal_pending(current))
+                        err = -ERESTARTSYS;
+                else
+                        err = break_ksm(vma, addr);
+        }
+        return err;
+}
+
+#ifdef CONFIG_SYSFS
+/*
+ * Only called through the sysfs control interface:
+ */
+static int unmerge_and_remove_all_rmap_items(void)
+{
+        struct mm_slot *mm_slot;
+        struct mm_struct *mm;
+        struct vm_area_struct *vma;
+        int err = 0;
+
+        spin_lock(&ksm_mmlist_lock);
+        ksm_scan.mm_slot = list_entry(ksm_mm_head.mm_list.next,
+                                                struct mm_slot, mm_list);
+        spin_unlock(&ksm_mmlist_lock);
+
+        for (mm_slot = ksm_scan.mm_slot;
+                        mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot) {
+                mm = mm_slot->mm;
+                down_read(&mm->mmap_sem);
+                for (vma = mm->mmap; vma; vma = vma->vm_next) {
+                        if (ksm_test_exit(mm))
+                                break;
+                        if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+                                continue;
+                        err = unmerge_ksm_pages(vma,
+                                                vma->vm_start, vma->vm_end);
+                        if (err)
+                                goto error;
+                }
+
+                remove_trailing_rmap_items(mm_slot, mm_slot->rmap_list.next);
+
+                spin_lock(&ksm_mmlist_lock);
+                ksm_scan.mm_slot = list_entry(mm_slot->mm_list.next,
+                                                struct mm_slot, mm_list);
+                if (ksm_test_exit(mm)) {
+                        hlist_del(&mm_slot->link);
+                        list_del(&mm_slot->mm_list);
+                        spin_unlock(&ksm_mmlist_lock);
+
+                        free_mm_slot(mm_slot);
+                        clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+                        up_read(&mm->mmap_sem);
+                        mmdrop(mm);
+                } else {
+                        spin_unlock(&ksm_mmlist_lock);
+                        up_read(&mm->mmap_sem);
+                }
+        }
+
+        ksm_scan.seqnr = 0;
+        return 0;
+
+error:
+        up_read(&mm->mmap_sem);
+        spin_lock(&ksm_mmlist_lock);
+        ksm_scan.mm_slot = &ksm_mm_head;
+        spin_unlock(&ksm_mmlist_lock);
+        return err;
+}
+#endif /* CONFIG_SYSFS */
+
+static u32 calc_checksum(struct page *page)
+{
+        u32 checksum;
+        void *addr = kmap_atomic(page, KM_USER0);
+        checksum = jhash2(addr, PAGE_SIZE / 4, 17);
+        kunmap_atomic(addr, KM_USER0);
+        return checksum;
+}
+
+static int memcmp_pages(struct page *page1, struct page *page2)
+{
+        char *addr1, *addr2;
+        int ret;
+
+        addr1 = kmap_atomic(page1, KM_USER0);
+        addr2 = kmap_atomic(page2, KM_USER1);
+        ret = memcmp(addr1, addr2, PAGE_SIZE);
+        kunmap_atomic(addr2, KM_USER1);
+        kunmap_atomic(addr1, KM_USER0);
+        return ret;
+}
+
+static inline int pages_identical(struct page *page1, struct page *page2)
+{
+        return !memcmp_pages(page1, page2);
+}
+
+static int write_protect_page(struct vm_area_struct *vma, struct page *page,
+                              pte_t *orig_pte)
+{
+        struct mm_struct *mm = vma->vm_mm;
+        unsigned long addr;
+        pte_t *ptep;
+        spinlock_t *ptl;
+        int swapped;
+        int err = -EFAULT;
+
+        addr = page_address_in_vma(page, vma);
+        if (addr == -EFAULT)
+                goto out;
+
+        ptep = page_check_address(page, mm, addr, &ptl, 0);
+        if (!ptep)
+                goto out;
+
+        if (pte_write(*ptep)) {
+                pte_t entry;
+
+                swapped = PageSwapCache(page);
+                flush_cache_page(vma, addr, page_to_pfn(page));
+                /*
+                 * Ok this is tricky, when get_user_pages_fast() run it doesnt
+                 * take any lock, therefore the check that we are going to make
+                 * with the pagecount against the mapcount is racey and
+                 * O_DIRECT can happen right after the check.
+                 * So we clear the pte and flush the tlb before the check
+                 * this assure us that no O_DIRECT can happen after the check
+                 * or in the middle of the check.
+                 */
+                entry = ptep_clear_flush(vma, addr, ptep);
+                /*
+                 * Check that no O_DIRECT or similar I/O is in progress on the
+                 * page
+                 */
+                if ((page_mapcount(page) + 2 + swapped) != page_count(page)) {
+                        set_pte_at_notify(mm, addr, ptep, entry);
+                        goto out_unlock;
+                }
+                entry = pte_wrprotect(entry);
+                set_pte_at_notify(mm, addr, ptep, entry);
+        }
+        *orig_pte = *ptep;
+        err = 0;
+
+out_unlock:
+        pte_unmap_unlock(ptep, ptl);
+out:
+        return err;
+}
+
+/**
+ * replace_page - replace page in vma by new ksm page
+ * @vma:      vma that holds the pte pointing to oldpage
+ * @oldpage:  the page we are replacing by newpage
+ * @newpage:  the ksm page we replace oldpage by
+ * @orig_pte: the original value of the pte
+ *
+ * Returns 0 on success, -EFAULT on failure.
+ */
+static int replace_page(struct vm_area_struct *vma, struct page *oldpage,
+                        struct page *newpage, pte_t orig_pte)
+{
+        struct mm_struct *mm = vma->vm_mm;
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd;
+        pte_t *ptep;
+        spinlock_t *ptl;
+        unsigned long addr;
+        pgprot_t prot;
+        int err = -EFAULT;
+
+        prot = vm_get_page_prot(vma->vm_flags & ~VM_WRITE);
+
+        addr = page_address_in_vma(oldpage, vma);
+        if (addr == -EFAULT)
+                goto out;
+
+        pgd = pgd_offset(mm, addr);
+        if (!pgd_present(*pgd))
+                goto out;
+
+        pud = pud_offset(pgd, addr);
+        if (!pud_present(*pud))
+                goto out;
+
+        pmd = pmd_offset(pud, addr);
+        if (!pmd_present(*pmd))
+                goto out;
+
+        ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
+        if (!pte_same(*ptep, orig_pte)) {
+                pte_unmap_unlock(ptep, ptl);
+                goto out;
+        }
+
+        get_page(newpage);
+        page_add_ksm_rmap(newpage);
+
+        flush_cache_page(vma, addr, pte_pfn(*ptep));
+        ptep_clear_flush(vma, addr, ptep);
+        set_pte_at_notify(mm, addr, ptep, mk_pte(newpage, prot));
+
+        page_remove_rmap(oldpage);
+        put_page(oldpage);
+
+        pte_unmap_unlock(ptep, ptl);
+        err = 0;
+out:
+        return err;
+}
+
+/*
+ * try_to_merge_one_page - take two pages and merge them into one
+ * @vma: the vma that hold the pte pointing into oldpage
+ * @oldpage: the page that we want to replace with newpage
+ * @newpage: the page that we want to map instead of oldpage
+ *
+ * Note:
+ * oldpage should be a PageAnon page, while newpage should be a PageKsm page,
+ * or a newly allocated kernel page which page_add_ksm_rmap will make PageKsm.
+ *
+ * This function returns 0 if the pages were merged, -EFAULT otherwise.
+ */
+static int try_to_merge_one_page(struct vm_area_struct *vma,
+                                 struct page *oldpage,
+                                 struct page *newpage)
+{
+        pte_t orig_pte = __pte(0);
+        int err = -EFAULT;
+
+        if (!(vma->vm_flags & VM_MERGEABLE))
+                goto out;
+
+        if (!PageAnon(oldpage))
+                goto out;
+
+        get_page(newpage);
+        get_page(oldpage);
+
+        /*
+         * We need the page lock to read a stable PageSwapCache in
+         * write_protect_page().  We use trylock_page() instead of
+         * lock_page() because we don't want to wait here - we
+         * prefer to continue scanning and merging different pages,
+         * then come back to this page when it is unlocked.
+         */
+        if (!trylock_page(oldpage))
+                goto out_putpage;
+        /*
+         * If this anonymous page is mapped only here, its pte may need
+         * to be write-protected.  If it's mapped elsewhere, all of its
+         * ptes are necessarily already write-protected.  But in either
+         * case, we need to lock and check page_count is not raised.
+         */
+        if (write_protect_page(vma, oldpage, &orig_pte)) {
+                unlock_page(oldpage);
+                goto out_putpage;
+        }
+        unlock_page(oldpage);
+
+        if (pages_identical(oldpage, newpage))
+                err = replace_page(vma, oldpage, newpage, orig_pte);
+
+out_putpage:
+        put_page(oldpage);
+        put_page(newpage);
+out:
+        return err;
+}
+
+/*
+ * try_to_merge_with_ksm_page - like try_to_merge_two_pages,
+ * but no new kernel page is allocated: kpage must already be a ksm page.
+ */
+static int try_to_merge_with_ksm_page(struct mm_struct *mm1,
+                                      unsigned long addr1,
+                                      struct page *page1,
+                                      struct page *kpage)
+{
+        struct vm_area_struct *vma;
+        int err = -EFAULT;
+
+        down_read(&mm1->mmap_sem);
+        if (ksm_test_exit(mm1))
+                goto out;
+
+        vma = find_vma(mm1, addr1);
+        if (!vma || vma->vm_start > addr1)
+                goto out;
+
+        err = try_to_merge_one_page(vma, page1, kpage);
+out:
+        up_read(&mm1->mmap_sem);
+        return err;
+}
+
+/*
+ * try_to_merge_two_pages - take two identical pages and prepare them
+ * to be merged into one page.
+ *
+ * This function returns 0 if we successfully mapped two identical pages
+ * into one page, -EFAULT otherwise.
+ *
+ * Note that this function allocates a new kernel page: if one of the pages
+ * is already a ksm page, try_to_merge_with_ksm_page should be used.
+ */
+static int try_to_merge_two_pages(struct mm_struct *mm1, unsigned long addr1,
+                                  struct page *page1, struct mm_struct *mm2,
+                                  unsigned long addr2, struct page *page2)
+{
+        struct vm_area_struct *vma;
+        struct page *kpage;
+        int err = -EFAULT;
+
+        /*
+         * The number of nodes in the stable tree
+         * is the number of kernel pages that we hold.
+         */
+        if (ksm_max_kernel_pages &&
+            ksm_max_kernel_pages <= ksm_pages_shared)
+                return err;
+
+        kpage = alloc_page(GFP_HIGHUSER);
+        if (!kpage)
+                return err;
+
+        down_read(&mm1->mmap_sem);
+        if (ksm_test_exit(mm1)) {
+                up_read(&mm1->mmap_sem);
+                goto out;
+        }
+        vma = find_vma(mm1, addr1);
+        if (!vma || vma->vm_start > addr1) {
+                up_read(&mm1->mmap_sem);
+                goto out;
+        }
+
+        copy_user_highpage(kpage, page1, addr1, vma);
+        err = try_to_merge_one_page(vma, page1, kpage);
+        up_read(&mm1->mmap_sem);
+
+        if (!err) {
+                err = try_to_merge_with_ksm_page(mm2, addr2, page2, kpage);
+                /*
+                 * If that fails, we have a ksm page with only one pte
+                 * pointing to it: so break it.
+                 */
+                if (err)
+                        break_cow(mm1, addr1);
+        }
+out:
+        put_page(kpage);
+        return err;
+}
+
+/*
+ * stable_tree_search - search page inside the stable tree
+ * @page: the page that we are searching identical pages to.
+ * @page2: pointer into identical page that we are holding inside the stable
+ *         tree that we have found.
+ * @rmap_item: the reverse mapping item
+ *
+ * This function checks if there is a page inside the stable tree
+ * with identical content to the page that we are scanning right now.
+ *
+ * This function return rmap_item pointer to the identical item if found,
+ * NULL otherwise.
+ */
+static struct rmap_item *stable_tree_search(struct page *page,
+                                            struct page **page2,
+                                            struct rmap_item *rmap_item)
+{
+        struct rb_node *node = root_stable_tree.rb_node;
+
+        while (node) {
+                struct rmap_item *tree_rmap_item, *next_rmap_item;
+                int ret;
+
+                tree_rmap_item = rb_entry(node, struct rmap_item, node);
+                while (tree_rmap_item) {
+                        BUG_ON(!in_stable_tree(tree_rmap_item));
+                        cond_resched();
+                        page2[0] = get_ksm_page(tree_rmap_item);
+                        if (page2[0])
+                                break;
+                        next_rmap_item = tree_rmap_item->next;
+                        remove_rmap_item_from_tree(tree_rmap_item);
+                        tree_rmap_item = next_rmap_item;
+                }
+                if (!tree_rmap_item)
+                        return NULL;
+
+                ret = memcmp_pages(page, page2[0]);
+
+                if (ret < 0) {
+                        put_page(page2[0]);
+                        node = node->rb_left;
+                } else if (ret > 0) {
+                        put_page(page2[0]);
+                        node = node->rb_right;
+                } else {
+                        return tree_rmap_item;
+                }
+        }
+
+        return NULL;
+}
+
+/*
+ * stable_tree_insert - insert rmap_item pointing to new ksm page
+ * into the stable tree.
+ *
+ * @page: the page that we are searching identical page to inside the stable
+ *        tree.
+ * @rmap_item: pointer to the reverse mapping item.
+ *
+ * This function returns rmap_item if success, NULL otherwise.
+ */
+static struct rmap_item *stable_tree_insert(struct page *page,
+                                            struct rmap_item *rmap_item)
+{
+        struct rb_node **new = &root_stable_tree.rb_node;
+        struct rb_node *parent = NULL;
+
+        while (*new) {
+                struct rmap_item *tree_rmap_item, *next_rmap_item;
+                struct page *tree_page;
+                int ret;
+
+                tree_rmap_item = rb_entry(*new, struct rmap_item, node);
+                while (tree_rmap_item) {
+                        BUG_ON(!in_stable_tree(tree_rmap_item));
+                        cond_resched();
+                        tree_page = get_ksm_page(tree_rmap_item);
+                        if (tree_page)
+                                break;
+                        next_rmap_item = tree_rmap_item->next;
+                        remove_rmap_item_from_tree(tree_rmap_item);
+                        tree_rmap_item = next_rmap_item;
+                }
+                if (!tree_rmap_item)
+                        return NULL;
+
+                ret = memcmp_pages(page, tree_page);
+                put_page(tree_page);
+
+                parent = *new;
+                if (ret < 0)
+                        new = &parent->rb_left;
+                else if (ret > 0)
+                        new = &parent->rb_right;
+                else {
+                        /*
+                         * It is not a bug that stable_tree_search() didn't
+                         * find this node: because at that time our page was
+                         * not yet write-protected, so may have changed since.
+                         */
+                        return NULL;
+                }
+        }
+
+        rmap_item->address |= NODE_FLAG | STABLE_FLAG;
+        rmap_item->next = NULL;
+        rb_link_node(&rmap_item->node, parent, new);
+        rb_insert_color(&rmap_item->node, &root_stable_tree);
+
+        ksm_pages_shared++;
+        return rmap_item;
+}
+
+/*
+ * unstable_tree_search_insert - search and insert items into the unstable tree.
+ *
+ * @page: the page that we are going to search for identical page or to insert
+ *        into the unstable tree
+ * @page2: pointer into identical page that was found inside the unstable tree
+ * @rmap_item: the reverse mapping item of page
+ *
+ * This function searches for a page in the unstable tree identical to the
+ * page currently being scanned; and if no identical page is found in the
+ * tree, we insert rmap_item as a new object into the unstable tree.
+ *
+ * This function returns pointer to rmap_item found to be identical
+ * to the currently scanned page, NULL otherwise.
+ *
+ * This function does both searching and inserting, because they share
+ * the same walking algorithm in an rbtree.
+ */
+static struct rmap_item *unstable_tree_search_insert(struct page *page,
+                                                struct page **page2,
+                                                struct rmap_item *rmap_item)
+{
+        struct rb_node **new = &root_unstable_tree.rb_node;
+        struct rb_node *parent = NULL;
+
+        while (*new) {
+                struct rmap_item *tree_rmap_item;
+                int ret;
+
+                tree_rmap_item = rb_entry(*new, struct rmap_item, node);
+                page2[0] = get_mergeable_page(tree_rmap_item);
+                if (!page2[0])
+                        return NULL;
+
+                /*
+                 * Don't substitute an unswappable ksm page
+                 * just for one good swappable forked page.
+                 */
+                if (page == page2[0]) {
+                        put_page(page2[0]);
+                        return NULL;
+                }
+
+                ret = memcmp_pages(page, page2[0]);
+
+                parent = *new;
+                if (ret < 0) {
+                        put_page(page2[0]);
+                        new = &parent->rb_left;
+                } else if (ret > 0) {
+                        put_page(page2[0]);
+                        new = &parent->rb_right;
+                } else {
+                        return tree_rmap_item;
+                }
+        }
+
+        rmap_item->address |= NODE_FLAG;
+        rmap_item->address |= (ksm_scan.seqnr & SEQNR_MASK);
+        rb_link_node(&rmap_item->node, parent, new);
+        rb_insert_color(&rmap_item->node, &root_unstable_tree);
+
+        ksm_pages_unshared++;
+        return NULL;
+}
+
+/*
+ * stable_tree_append - add another rmap_item to the linked list of
+ * rmap_items hanging off a given node of the stable tree, all sharing
+ * the same ksm page.
+ */
+static void stable_tree_append(struct rmap_item *rmap_item,
+                               struct rmap_item *tree_rmap_item)
+{
+        rmap_item->next = tree_rmap_item->next;
+        rmap_item->prev = tree_rmap_item;
+
+        if (tree_rmap_item->next)
+                tree_rmap_item->next->prev = rmap_item;
+
+        tree_rmap_item->next = rmap_item;
+        rmap_item->address |= STABLE_FLAG;
+
+        ksm_pages_sharing++;
+}
+
+/*
+ * cmp_and_merge_page - first see if page can be merged into the stable tree;
+ * if not, compare checksum to previous and if it's the same, see if page can
+ * be inserted into the unstable tree, or merged with a page already there and
+ * both transferred to the stable tree.
+ *
+ * @page: the page that we are searching identical page to.
+ * @rmap_item: the reverse mapping into the virtual address of this page
+ */
+static void cmp_and_merge_page(struct page *page, struct rmap_item *rmap_item)
+{
+        struct page *page2[1];
+        struct rmap_item *tree_rmap_item;
+        unsigned int checksum;
+        int err;
+
+        if (in_stable_tree(rmap_item))
+                remove_rmap_item_from_tree(rmap_item);
+
+        /* We first start with searching the page inside the stable tree */
+        tree_rmap_item = stable_tree_search(page, page2, rmap_item);
+        if (tree_rmap_item) {
+                if (page == page2[0])                   /* forked */
+                        err = 0;
+                else
+                        err = try_to_merge_with_ksm_page(rmap_item->mm,
+                                                         rmap_item->address,
+                                                         page, page2[0]);
+                put_page(page2[0]);
+
+                if (!err) {
+                        /*
+                         * The page was successfully merged:
+                         * add its rmap_item to the stable tree.
+                         */
+                        stable_tree_append(rmap_item, tree_rmap_item);
+                }
+                return;
+        }
+
+        /*
+         * A ksm page might have got here by fork, but its other
+         * references have already been removed from the stable tree.
+         * Or it might be left over from a break_ksm which failed
+         * when the mem_cgroup had reached its limit: try again now.
+         */
+        if (PageKsm(page))
+                break_cow(rmap_item->mm, rmap_item->address);
+
+        /*
+         * In case the hash value of the page was changed from the last time we
+         * have calculated it, this page to be changed frequely, therefore we
+         * don't want to insert it to the unstable tree, and we don't want to
+         * waste our time to search if there is something identical to it there.
+         */
+        checksum = calc_checksum(page);
+        if (rmap_item->oldchecksum != checksum) {
+                rmap_item->oldchecksum = checksum;
+                return;
+        }
+
+        tree_rmap_item = unstable_tree_search_insert(page, page2, rmap_item);
+        if (tree_rmap_item) {
+                err = try_to_merge_two_pages(rmap_item->mm,
+                                             rmap_item->address, page,
+                                             tree_rmap_item->mm,
+                                             tree_rmap_item->address, page2[0]);
+                /*
+                 * As soon as we merge this page, we want to remove the
+                 * rmap_item of the page we have merged with from the unstable
+                 * tree, and insert it instead as new node in the stable tree.
+                 */
+                if (!err) {
+                        rb_erase(&tree_rmap_item->node, &root_unstable_tree);
+                        tree_rmap_item->address &= ~NODE_FLAG;
+                        ksm_pages_unshared--;
+
+                        /*
+                         * If we fail to insert the page into the stable tree,
+                         * we will have 2 virtual addresses that are pointing
+                         * to a ksm page left outside the stable tree,
+                         * in which case we need to break_cow on both.
+                         */
+                        if (stable_tree_insert(page2[0], tree_rmap_item))
+                                stable_tree_append(rmap_item, tree_rmap_item);
+                        else {
+                                break_cow(tree_rmap_item->mm,
+                                                tree_rmap_item->address);
+                                break_cow(rmap_item->mm, rmap_item->address);
+                        }
+                }
+
+                put_page(page2[0]);
+        }
+}
+
+static struct rmap_item *get_next_rmap_item(struct mm_slot *mm_slot,
+                                            struct list_head *cur,
+                                            unsigned long addr)
+{
+        struct rmap_item *rmap_item;
+
+        while (cur != &mm_slot->rmap_list) {
+                rmap_item = list_entry(cur, struct rmap_item, link);
+                if ((rmap_item->address & PAGE_MASK) == addr) {
+                        if (!in_stable_tree(rmap_item))
+                                remove_rmap_item_from_tree(rmap_item);
+                        return rmap_item;
+                }
+                if (rmap_item->address > addr)
+                        break;
+                cur = cur->next;
+                remove_rmap_item_from_tree(rmap_item);
+                list_del(&rmap_item->link);
+                free_rmap_item(rmap_item);
+        }
+
+        rmap_item = alloc_rmap_item();
+        if (rmap_item) {
+                /* It has already been zeroed */
+                rmap_item->mm = mm_slot->mm;
+                rmap_item->address = addr;
+                list_add_tail(&rmap_item->link, cur);
+        }
+        return rmap_item;
+}
+
+static struct rmap_item *scan_get_next_rmap_item(struct page **page)
+{
+        struct mm_struct *mm;
+        struct mm_slot *slot;
+        struct vm_area_struct *vma;
+        struct rmap_item *rmap_item;
+
+        if (list_empty(&ksm_mm_head.mm_list))
+                return NULL;
+
+        slot = ksm_scan.mm_slot;
+        if (slot == &ksm_mm_head) {
+                root_unstable_tree = RB_ROOT;
+
+                spin_lock(&ksm_mmlist_lock);
+                slot = list_entry(slot->mm_list.next, struct mm_slot, mm_list);
+                ksm_scan.mm_slot = slot;
+                spin_unlock(&ksm_mmlist_lock);
+next_mm:
+                ksm_scan.address = 0;
+                ksm_scan.rmap_item = list_entry(&slot->rmap_list,
+                                                struct rmap_item, link);
+        }
+
+        mm = slot->mm;
+        down_read(&mm->mmap_sem);
+        if (ksm_test_exit(mm))
+                vma = NULL;
+        else
+                vma = find_vma(mm, ksm_scan.address);
+
+        for (; vma; vma = vma->vm_next) {
+                if (!(vma->vm_flags & VM_MERGEABLE))
+                        continue;
+                if (ksm_scan.address < vma->vm_start)
+                        ksm_scan.address = vma->vm_start;
+                if (!vma->anon_vma)
+                        ksm_scan.address = vma->vm_end;
+
+                while (ksm_scan.address < vma->vm_end) {
+                        if (ksm_test_exit(mm))
+                                break;
+                        *page = follow_page(vma, ksm_scan.address, FOLL_GET);
+                        if (*page && PageAnon(*page)) {
+                                flush_anon_page(vma, *page, ksm_scan.address);
+                                flush_dcache_page(*page);
+                                rmap_item = get_next_rmap_item(slot,
+                                        ksm_scan.rmap_item->link.next,
+                                        ksm_scan.address);
+                                if (rmap_item) {
+                                        ksm_scan.rmap_item = rmap_item;
+                                        ksm_scan.address += PAGE_SIZE;
+                                } else
+                                        put_page(*page);
+                                up_read(&mm->mmap_sem);
+                                return rmap_item;
+                        }
+                        if (*page)
+                                put_page(*page);
+                        ksm_scan.address += PAGE_SIZE;
+                        cond_resched();
+                }
+        }
+
+        if (ksm_test_exit(mm)) {
+                ksm_scan.address = 0;
+                ksm_scan.rmap_item = list_entry(&slot->rmap_list,
+                                                struct rmap_item, link);
+        }
+        /*
+         * Nuke all the rmap_items that are above this current rmap:
+         * because there were no VM_MERGEABLE vmas with such addresses.
+         */
+        remove_trailing_rmap_items(slot, ksm_scan.rmap_item->link.next);
+
+        spin_lock(&ksm_mmlist_lock);
+        ksm_scan.mm_slot = list_entry(slot->mm_list.next,
+                                                struct mm_slot, mm_list);
+        if (ksm_scan.address == 0) {
+                /*
+                 * We've completed a full scan of all vmas, holding mmap_sem
+                 * throughout, and found no VM_MERGEABLE: so do the same as
+                 * __ksm_exit does to remove this mm from all our lists now.
+                 * This applies either when cleaning up after __ksm_exit
+                 * (but beware: we can reach here even before __ksm_exit),
+                 * or when all VM_MERGEABLE areas have been unmapped (and
+                 * mmap_sem then protects against race with MADV_MERGEABLE).
+                 */
+                hlist_del(&slot->link);
+                list_del(&slot->mm_list);
+                spin_unlock(&ksm_mmlist_lock);
+
+                free_mm_slot(slot);
+                clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+                up_read(&mm->mmap_sem);
+                mmdrop(mm);
+        } else {
+                spin_unlock(&ksm_mmlist_lock);
+                up_read(&mm->mmap_sem);
+        }
+
+        /* Repeat until we've completed scanning the whole list */
+        slot = ksm_scan.mm_slot;
+        if (slot != &ksm_mm_head)
+                goto next_mm;
+
+        ksm_scan.seqnr++;
+        return NULL;
+}
+
+/**
+ * ksm_do_scan  - the ksm scanner main worker function.
+ * @scan_npages - number of pages we want to scan before we return.
+ */
+static void ksm_do_scan(unsigned int scan_npages)
+{
+        struct rmap_item *rmap_item;
+        struct page *page;
+
+        while (scan_npages--) {
+                cond_resched();
+                rmap_item = scan_get_next_rmap_item(&page);
+                if (!rmap_item)
+                        return;
+                if (!PageKsm(page) || !in_stable_tree(rmap_item))
+                        cmp_and_merge_page(page, rmap_item);
+                else if (page_mapcount(page) == 1) {
+                        /*
+                         * Replace now-unshared ksm page by ordinary page.
+                         */
+                        break_cow(rmap_item->mm, rmap_item->address);
+                        remove_rmap_item_from_tree(rmap_item);
+                        rmap_item->oldchecksum = calc_checksum(page);
+                }
+                put_page(page);
+        }
+}
+
+static int ksmd_should_run(void)
+{
+        return (ksm_run & KSM_RUN_MERGE) && !list_empty(&ksm_mm_head.mm_list);
+}
+
+static int ksm_scan_thread(void *nothing)
+{
+        set_user_nice(current, 5);
+
+        while (!kthread_should_stop()) {
+                mutex_lock(&ksm_thread_mutex);
+                if (ksmd_should_run())
+                        ksm_do_scan(ksm_thread_pages_to_scan);
+                mutex_unlock(&ksm_thread_mutex);
+
+                if (ksmd_should_run()) {
+                        schedule_timeout_interruptible(
+                                msecs_to_jiffies(ksm_thread_sleep_millisecs));
+                } else {
+                        wait_event_interruptible(ksm_thread_wait,
+                                ksmd_should_run() || kthread_should_stop());
+                }
+        }
+        return 0;
+}
+
+int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
+                unsigned long end, int advice, unsigned long *vm_flags)
+{
+        struct mm_struct *mm = vma->vm_mm;
+        int err;
+
+        switch (advice) {
+        case MADV_MERGEABLE:
+                /*
+                 * Be somewhat over-protective for now!
+                 */
+                if (*vm_flags & (VM_MERGEABLE | VM_SHARED  | VM_MAYSHARE   |
+                                 VM_PFNMAP    | VM_IO      | VM_DONTEXPAND |
+                                 VM_RESERVED  | VM_HUGETLB | VM_INSERTPAGE |
+                                 VM_MIXEDMAP  | VM_SAO))
+                        return 0;               /* just ignore the advice */
+
+                if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) {
+                        err = __ksm_enter(mm);
+                        if (err)
+                                return err;
+                }
+
+                *vm_flags |= VM_MERGEABLE;
+                break;
+
+        case MADV_UNMERGEABLE:
+                if (!(*vm_flags & VM_MERGEABLE))
+                        return 0;               /* just ignore the advice */
+
+                if (vma->anon_vma) {
+                        err = unmerge_ksm_pages(vma, start, end);
+                        if (err)
+                                return err;
+                }
+
+                *vm_flags &= ~VM_MERGEABLE;
+                break;
+        }
+
+        return 0;
+}
+
+int __ksm_enter(struct mm_struct *mm)
+{
+        struct mm_slot *mm_slot;
+        int needs_wakeup;
+
+        mm_slot = alloc_mm_slot();
+        if (!mm_slot)
+                return -ENOMEM;
+
+        /* Check ksm_run too?  Would need tighter locking */
+        needs_wakeup = list_empty(&ksm_mm_head.mm_list);
+
+        spin_lock(&ksm_mmlist_lock);
+        insert_to_mm_slots_hash(mm, mm_slot);
+        /*
+         * Insert just behind the scanning cursor, to let the area settle
+         * down a little; when fork is followed by immediate exec, we don't
+         * want ksmd to waste time setting up and tearing down an rmap_list.
+         */
+        list_add_tail(&mm_slot->mm_list, &ksm_scan.mm_slot->mm_list);
+        spin_unlock(&ksm_mmlist_lock);
+
+        set_bit(MMF_VM_MERGEABLE, &mm->flags);
+        atomic_inc(&mm->mm_count);
+
+        if (needs_wakeup)
+                wake_up_interruptible(&ksm_thread_wait);
+
+        return 0;
+}
+
+void __ksm_exit(struct mm_struct *mm)
+{
+        struct mm_slot *mm_slot;
+        int easy_to_free = 0;
+
+        /*
+         * This process is exiting: if it's straightforward (as is the
+         * case when ksmd was never running), free mm_slot immediately.
+         * But if it's at the cursor or has rmap_items linked to it, use
+         * mmap_sem to synchronize with any break_cows before pagetables
+         * are freed, and leave the mm_slot on the list for ksmd to free.
+         * Beware: ksm may already have noticed it exiting and freed the slot.
+         */
+
+        spin_lock(&ksm_mmlist_lock);
+        mm_slot = get_mm_slot(mm);
+        if (mm_slot && ksm_scan.mm_slot != mm_slot) {
+                if (list_empty(&mm_slot->rmap_list)) {
+                        hlist_del(&mm_slot->link);
+                        list_del(&mm_slot->mm_list);
+                        easy_to_free = 1;
+                } else {
+                        list_move(&mm_slot->mm_list,
+                                  &ksm_scan.mm_slot->mm_list);
+                }
+        }
+        spin_unlock(&ksm_mmlist_lock);
+
+        if (easy_to_free) {
+                free_mm_slot(mm_slot);
+                clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+                mmdrop(mm);
+        } else if (mm_slot) {
+                down_write(&mm->mmap_sem);
+                up_write(&mm->mmap_sem);
+        }
+}
+
+#ifdef CONFIG_SYSFS
+/*
+ * This all compiles without CONFIG_SYSFS, but is a waste of space.
+ */
+
+#define KSM_ATTR_RO(_name) \
+        static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+#define KSM_ATTR(_name) \
+        static struct kobj_attribute _name##_attr = \
+                __ATTR(_name, 0644, _name##_show, _name##_store)
+
+static ssize_t sleep_millisecs_show(struct kobject *kobj,
+                                    struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%u\n", ksm_thread_sleep_millisecs);
+}
+
+static ssize_t sleep_millisecs_store(struct kobject *kobj,
+                                     struct kobj_attribute *attr,
+                                     const char *buf, size_t count)
+{
+        unsigned long msecs;
+        int err;
+
+        err = strict_strtoul(buf, 10, &msecs);
+        if (err || msecs > UINT_MAX)
+                return -EINVAL;
+
+        ksm_thread_sleep_millisecs = msecs;
+
+        return count;
+}
+KSM_ATTR(sleep_millisecs);
+
+static ssize_t pages_to_scan_show(struct kobject *kobj,
+                                  struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%u\n", ksm_thread_pages_to_scan);
+}
+
+static ssize_t pages_to_scan_store(struct kobject *kobj,
+                                   struct kobj_attribute *attr,
+                                   const char *buf, size_t count)
+{
+        int err;
+        unsigned long nr_pages;
+
+        err = strict_strtoul(buf, 10, &nr_pages);
+        if (err || nr_pages > UINT_MAX)
+                return -EINVAL;
+
+        ksm_thread_pages_to_scan = nr_pages;
+
+        return count;
+}
+KSM_ATTR(pages_to_scan);
+
+static ssize_t run_show(struct kobject *kobj, struct kobj_attribute *attr,
+                        char *buf)
+{
+        return sprintf(buf, "%u\n", ksm_run);
+}
+
+static ssize_t run_store(struct kobject *kobj, struct kobj_attribute *attr,
+                         const char *buf, size_t count)
+{
+        int err;
+        unsigned long flags;
+
+        err = strict_strtoul(buf, 10, &flags);
+        if (err || flags > UINT_MAX)
+                return -EINVAL;
+        if (flags > KSM_RUN_UNMERGE)
+                return -EINVAL;
+
+        /*
+         * KSM_RUN_MERGE sets ksmd running, and 0 stops it running.
+         * KSM_RUN_UNMERGE stops it running and unmerges all rmap_items,
+         * breaking COW to free the unswappable pages_shared (but leaves
+         * mm_slots on the list for when ksmd may be set running again).
+         */
+
+        mutex_lock(&ksm_thread_mutex);
+        if (ksm_run != flags) {
+                ksm_run = flags;
+                if (flags & KSM_RUN_UNMERGE) {
+                        current->flags |= PF_OOM_ORIGIN;
+                        err = unmerge_and_remove_all_rmap_items();
+                        current->flags &= ~PF_OOM_ORIGIN;
+                        if (err) {
+                                ksm_run = KSM_RUN_STOP;
+                                count = err;
+                        }
+                }
+        }
+        mutex_unlock(&ksm_thread_mutex);
+
+        if (flags & KSM_RUN_MERGE)
+                wake_up_interruptible(&ksm_thread_wait);
+
+        return count;
+}
+KSM_ATTR(run);
+
+static ssize_t max_kernel_pages_store(struct kobject *kobj,
+                                      struct kobj_attribute *attr,
+                                      const char *buf, size_t count)
+{
+        int err;
+        unsigned long nr_pages;
+
+        err = strict_strtoul(buf, 10, &nr_pages);
+        if (err)
+                return -EINVAL;
+
+        ksm_max_kernel_pages = nr_pages;
+
+        return count;
+}
+
+static ssize_t max_kernel_pages_show(struct kobject *kobj,
+                                     struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%lu\n", ksm_max_kernel_pages);
+}
+KSM_ATTR(max_kernel_pages);
+
+static ssize_t pages_shared_show(struct kobject *kobj,
+                                 struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%lu\n", ksm_pages_shared);
+}
+KSM_ATTR_RO(pages_shared);
+
+static ssize_t pages_sharing_show(struct kobject *kobj,
+                                  struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%lu\n", ksm_pages_sharing);
+}
+KSM_ATTR_RO(pages_sharing);
+
+static ssize_t pages_unshared_show(struct kobject *kobj,
+                                   struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%lu\n", ksm_pages_unshared);
+}
+KSM_ATTR_RO(pages_unshared);
+
+static ssize_t pages_volatile_show(struct kobject *kobj,
+                                   struct kobj_attribute *attr, char *buf)
+{
+        long ksm_pages_volatile;
+
+        ksm_pages_volatile = ksm_rmap_items - ksm_pages_shared
+                                - ksm_pages_sharing - ksm_pages_unshared;
+        /*
+         * It was not worth any locking to calculate that statistic,
+         * but it might therefore sometimes be negative: conceal that.
+         */
+        if (ksm_pages_volatile < 0)
+                ksm_pages_volatile = 0;
+        return sprintf(buf, "%ld\n", ksm_pages_volatile);
+}
+KSM_ATTR_RO(pages_volatile);
+
+static ssize_t full_scans_show(struct kobject *kobj,
+                               struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%lu\n", ksm_scan.seqnr);
+}
+KSM_ATTR_RO(full_scans);
+
+static struct attribute *ksm_attrs[] = {
+        &sleep_millisecs_attr.attr,
+        &pages_to_scan_attr.attr,
+        &run_attr.attr,
+        &max_kernel_pages_attr.attr,
+        &pages_shared_attr.attr,
+        &pages_sharing_attr.attr,
+        &pages_unshared_attr.attr,
+        &pages_volatile_attr.attr,
+        &full_scans_attr.attr,
+        NULL,
+};
+
+static struct attribute_group ksm_attr_group = {
+        .attrs = ksm_attrs,
+        .name = "ksm",
+};
+#endif /* CONFIG_SYSFS */
+
+static int __init ksm_init(void)
+{
+        struct task_struct *ksm_thread;
+        int err;
+
+        ksm_max_kernel_pages = totalram_pages / 4;
+
+        err = ksm_slab_init();
+        if (err)
+                goto out;
+
+        err = mm_slots_hash_init();
+        if (err)
+                goto out_free1;
+
+        ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd");
+        if (IS_ERR(ksm_thread)) {
+                printk(KERN_ERR "ksm: creating kthread failed\n");
+                err = PTR_ERR(ksm_thread);
+                goto out_free2;
+        }
+
+#ifdef CONFIG_SYSFS
+        err = sysfs_create_group(mm_kobj, &ksm_attr_group);
+        if (err) {
+                printk(KERN_ERR "ksm: register sysfs failed\n");
+                kthread_stop(ksm_thread);
+                goto out_free2;
+        }
+#else
+        ksm_run = KSM_RUN_MERGE;        /* no way for user to start it */
+
+#endif /* CONFIG_SYSFS */
+
+        return 0;
+
+out_free2:
+        mm_slots_hash_free();
+out_free1:
+        ksm_slab_free();
+out:
+        return err;
+}
+module_init(ksm_init)
diff --git a/mm/madvise.c b/mm/madvise.c
index 76eb4193acdd..35b1479b7c9d 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -11,6 +11,7 @@
 #include <linux/mempolicy.h>
 #include <linux/hugetlb.h>
 #include <linux/sched.h>
+#include <linux/ksm.h>
 
 /*
  * Any behaviour which results in changes to the vma->vm_flags needs to
@@ -41,7 +42,7 @@ static long madvise_behavior(struct vm_area_struct * vma,
         struct mm_struct * mm = vma->vm_mm;
         int error = 0;
         pgoff_t pgoff;
-        int new_flags = vma->vm_flags;
+        unsigned long new_flags = vma->vm_flags;
 
         switch (behavior) {
         case MADV_NORMAL:
@@ -57,8 +58,18 @@ static long madvise_behavior(struct vm_area_struct * vma,
                 new_flags |= VM_DONTCOPY;
                 break;
         case MADV_DOFORK:
+                if (vma->vm_flags & VM_IO) {
+                        error = -EINVAL;
+                        goto out;
+                }
                 new_flags &= ~VM_DONTCOPY;
                 break;
+        case MADV_MERGEABLE:
+        case MADV_UNMERGEABLE:
+                error = ksm_madvise(vma, start, end, behavior, &new_flags);
+                if (error)
+                        goto out;
+                break;
         }
 
         if (new_flags == vma->vm_flags) {
@@ -207,41 +218,46 @@ static long madvise_remove(struct vm_area_struct *vma,
         return error;
 }
 
+#ifdef CONFIG_MEMORY_FAILURE
+/*
+ * Error injection support for memory error handling.
+ */
+static int madvise_hwpoison(unsigned long start, unsigned long end)
+{
+        int ret = 0;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        for (; start < end; start += PAGE_SIZE) {
+                struct page *p;
+                int ret = get_user_pages(current, current->mm, start, 1,
+                                                0, 0, &p, NULL);
+                if (ret != 1)
+                        return ret;
+                printk(KERN_INFO "Injecting memory failure for page %lx at %lx\n",
+                       page_to_pfn(p), start);
+                /* Ignore return value for now */
+                __memory_failure(page_to_pfn(p), 0, 1);
+                put_page(p);
+        }
+        return ret;
+}
+#endif
+
 static long
 madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
                 unsigned long start, unsigned long end, int behavior)
 {
-        long error;
-
         switch (behavior) {
-        case MADV_DOFORK:
-                if (vma->vm_flags & VM_IO) {
-                        error = -EINVAL;
-                        break;
-                }
-        case MADV_DONTFORK:
-        case MADV_NORMAL:
-        case MADV_SEQUENTIAL:
-        case MADV_RANDOM:
-                error = madvise_behavior(vma, prev, start, end, behavior);
-                break;
         case MADV_REMOVE:
-                error = madvise_remove(vma, prev, start, end);
-                break;
-
+                return madvise_remove(vma, prev, start, end);
         case MADV_WILLNEED:
-                error = madvise_willneed(vma, prev, start, end);
-                break;
-
+                return madvise_willneed(vma, prev, start, end);
         case MADV_DONTNEED:
-                error = madvise_dontneed(vma, prev, start, end);
-                break;
-
+                return madvise_dontneed(vma, prev, start, end);
         default:
-                BUG();
-                break;
+                return madvise_behavior(vma, prev, start, end, behavior);
         }
-        return error;
 }
 
 static int
@@ -256,12 +272,17 @@ madvise_behavior_valid(int behavior)
         case MADV_REMOVE:
         case MADV_WILLNEED:
         case MADV_DONTNEED:
+#ifdef CONFIG_KSM
+        case MADV_MERGEABLE:
+        case MADV_UNMERGEABLE:
+#endif
                 return 1;
 
         default:
                 return 0;
         }
 }
+
 /*
  * The madvise(2) system call.
  *
@@ -286,6 +307,12 @@ madvise_behavior_valid(int behavior)
  *              so the kernel can free resources associated with it.
  *  MADV_REMOVE - the application wants to free up the given range of
  *              pages and associated backing store.
+ *  MADV_DONTFORK - omit this area from child's address space when forking:
+ *              typically, to avoid COWing pages pinned by get_user_pages().
+ *  MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking.
+ *  MADV_MERGEABLE - the application recommends that KSM try to merge pages in
+ *              this area with pages of identical content from other such areas.
+ *  MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others.
  *
  * return values:
  *  zero    - success
@@ -307,6 +334,10 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
         int write;
         size_t len;
 
+#ifdef CONFIG_MEMORY_FAILURE
+        if (behavior == MADV_HWPOISON)
+                return madvise_hwpoison(start, start+len_in);
+#endif
         if (!madvise_behavior_valid(behavior))
                 return error;
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fd4529d86de5..f99f5991d6bb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -29,6 +29,7 @@
 #include <linux/rcupdate.h>
 #include <linux/limits.h>
 #include <linux/mutex.h>
+#include <linux/rbtree.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
 #include <linux/spinlock.h>
@@ -43,6 +44,7 @@
 
 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
 #define MEM_CGROUP_RECLAIM_RETRIES      5
+struct mem_cgroup *root_mem_cgroup __read_mostly;
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
@@ -53,6 +55,7 @@ static int really_do_swap_account __initdata = 1; /* for remember boot option*/
 #endif
 
 static DEFINE_MUTEX(memcg_tasklist);    /* can be hold under cgroup_mutex */
+#define SOFTLIMIT_EVENTS_THRESH (1000)
 
 /*
  * Statistics for memory cgroup.
@@ -66,6 +69,8 @@ enum mem_cgroup_stat_index {
         MEM_CGROUP_STAT_MAPPED_FILE,  /* # of pages charged as file rss */
         MEM_CGROUP_STAT_PGPGIN_COUNT,   /* # of pages paged in */
         MEM_CGROUP_STAT_PGPGOUT_COUNT,  /* # of pages paged out */
+        MEM_CGROUP_STAT_EVENTS, /* sum of pagein + pageout for internal use */
+        MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
 
         MEM_CGROUP_STAT_NSTATS,
 };
@@ -78,6 +83,20 @@ struct mem_cgroup_stat {
         struct mem_cgroup_stat_cpu cpustat[0];
 };
 
+static inline void
+__mem_cgroup_stat_reset_safe(struct mem_cgroup_stat_cpu *stat,
+                                enum mem_cgroup_stat_index idx)
+{
+        stat->count[idx] = 0;
+}
+
+static inline s64
+__mem_cgroup_stat_read_local(struct mem_cgroup_stat_cpu *stat,
+                                enum mem_cgroup_stat_index idx)
+{
+        return stat->count[idx];
+}
+
 /*
  * For accounting under irq disable, no need for increment preempt count.
  */
@@ -117,6 +136,12 @@ struct mem_cgroup_per_zone {
         unsigned long           count[NR_LRU_LISTS];
 
         struct zone_reclaim_stat reclaim_stat;
+        struct rb_node          tree_node;      /* RB tree node */
+        unsigned long long      usage_in_excess;/* Set to the value by which */
+                                                /* the soft limit is exceeded*/
+        bool                    on_tree;
+        struct mem_cgroup       *mem;           /* Back pointer, we cannot */
+                                                /* use container_of        */
 };
 /* Macro for accessing counter */
 #define MEM_CGROUP_ZSTAT(mz, idx)       ((mz)->count[(idx)])
@@ -130,6 +155,26 @@ struct mem_cgroup_lru_info {
 };
 
 /*
+ * Cgroups above their limits are maintained in a RB-Tree, independent of
+ * their hierarchy representation
+ */
+
+struct mem_cgroup_tree_per_zone {
+        struct rb_root rb_root;
+        spinlock_t lock;
+};
+
+struct mem_cgroup_tree_per_node {
+        struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_tree {
+        struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
+};
+
+static struct mem_cgroup_tree soft_limit_tree __read_mostly;
+
+/*
  * The memory controller data structure. The memory controller controls both
  * page cache and RSS per cgroup. We would eventually like to provide
  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
@@ -186,6 +231,13 @@ struct mem_cgroup {
         struct mem_cgroup_stat stat;
 };
 
+/*
+ * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
+ * limit reclaim to prevent infinite loops, if they ever occur.
+ */
+#define MEM_CGROUP_MAX_RECLAIM_LOOPS            (100)
+#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
+
 enum charge_type {
         MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
         MEM_CGROUP_CHARGE_TYPE_MAPPED,
@@ -200,13 +252,8 @@ enum charge_type {
 #define PCGF_CACHE      (1UL << PCG_CACHE)
 #define PCGF_USED       (1UL << PCG_USED)
 #define PCGF_LOCK       (1UL << PCG_LOCK)
-static const unsigned long
-pcg_default_flags[NR_CHARGE_TYPE] = {
-        PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */
-        PCGF_USED | PCGF_LOCK, /* Anon */
-        PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
-        0, /* FORCE */
-};
+/* Not used, but added here for completeness */
+#define PCGF_ACCT       (1UL << PCG_ACCT)
 
 /* for encoding cft->private value on file */
 #define _MEM                    (0)
@@ -215,15 +262,237 @@ pcg_default_flags[NR_CHARGE_TYPE] = {
 #define MEMFILE_TYPE(val)       (((val) >> 16) & 0xffff)
 #define MEMFILE_ATTR(val)       ((val) & 0xffff)
 
+/*
+ * Reclaim flags for mem_cgroup_hierarchical_reclaim
+ */
+#define MEM_CGROUP_RECLAIM_NOSWAP_BIT   0x0
+#define MEM_CGROUP_RECLAIM_NOSWAP       (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
+#define MEM_CGROUP_RECLAIM_SHRINK_BIT   0x1
+#define MEM_CGROUP_RECLAIM_SHRINK       (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
+#define MEM_CGROUP_RECLAIM_SOFT_BIT     0x2
+#define MEM_CGROUP_RECLAIM_SOFT         (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
+
 static void mem_cgroup_get(struct mem_cgroup *mem);
 static void mem_cgroup_put(struct mem_cgroup *mem);
 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
 
+static struct mem_cgroup_per_zone *
+mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
+{
+        return &mem->info.nodeinfo[nid]->zoneinfo[zid];
+}
+
+static struct mem_cgroup_per_zone *
+page_cgroup_zoneinfo(struct page_cgroup *pc)
+{
+        struct mem_cgroup *mem = pc->mem_cgroup;
+        int nid = page_cgroup_nid(pc);
+        int zid = page_cgroup_zid(pc);
+
+        if (!mem)
+                return NULL;
+
+        return mem_cgroup_zoneinfo(mem, nid, zid);
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_node_zone(int nid, int zid)
+{
+        return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_from_page(struct page *page)
+{
+        int nid = page_to_nid(page);
+        int zid = page_zonenum(page);
+
+        return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static void
+__mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
+                                struct mem_cgroup_per_zone *mz,
+                                struct mem_cgroup_tree_per_zone *mctz,
+                                unsigned long long new_usage_in_excess)
+{
+        struct rb_node **p = &mctz->rb_root.rb_node;
+        struct rb_node *parent = NULL;
+        struct mem_cgroup_per_zone *mz_node;
+
+        if (mz->on_tree)
+                return;
+
+        mz->usage_in_excess = new_usage_in_excess;
+        if (!mz->usage_in_excess)
+                return;
+        while (*p) {
+                parent = *p;
+                mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
+                                        tree_node);
+                if (mz->usage_in_excess < mz_node->usage_in_excess)
+                        p = &(*p)->rb_left;
+                /*
+                 * We can't avoid mem cgroups that are over their soft
+                 * limit by the same amount
+                 */
+                else if (mz->usage_in_excess >= mz_node->usage_in_excess)
+                        p = &(*p)->rb_right;
+        }
+        rb_link_node(&mz->tree_node, parent, p);
+        rb_insert_color(&mz->tree_node, &mctz->rb_root);
+        mz->on_tree = true;
+}
+
+static void
+__mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
+                                struct mem_cgroup_per_zone *mz,
+                                struct mem_cgroup_tree_per_zone *mctz)
+{
+        if (!mz->on_tree)
+                return;
+        rb_erase(&mz->tree_node, &mctz->rb_root);
+        mz->on_tree = false;
+}
+
+static void
+mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
+                                struct mem_cgroup_per_zone *mz,
+                                struct mem_cgroup_tree_per_zone *mctz)
+{
+        spin_lock(&mctz->lock);
+        __mem_cgroup_remove_exceeded(mem, mz, mctz);
+        spin_unlock(&mctz->lock);
+}
+
+static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem)
+{
+        bool ret = false;
+        int cpu;
+        s64 val;
+        struct mem_cgroup_stat_cpu *cpustat;
+
+        cpu = get_cpu();
+        cpustat = &mem->stat.cpustat[cpu];
+        val = __mem_cgroup_stat_read_local(cpustat, MEM_CGROUP_STAT_EVENTS);
+        if (unlikely(val > SOFTLIMIT_EVENTS_THRESH)) {
+                __mem_cgroup_stat_reset_safe(cpustat, MEM_CGROUP_STAT_EVENTS);
+                ret = true;
+        }
+        put_cpu();
+        return ret;
+}
+
+static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
+{
+        unsigned long long excess;
+        struct mem_cgroup_per_zone *mz;
+        struct mem_cgroup_tree_per_zone *mctz;
+        int nid = page_to_nid(page);
+        int zid = page_zonenum(page);
+        mctz = soft_limit_tree_from_page(page);
+
+        /*
+         * Necessary to update all ancestors when hierarchy is used.
+         * because their event counter is not touched.
+         */
+        for (; mem; mem = parent_mem_cgroup(mem)) {
+                mz = mem_cgroup_zoneinfo(mem, nid, zid);
+                excess = res_counter_soft_limit_excess(&mem->res);
+                /*
+                 * We have to update the tree if mz is on RB-tree or
+                 * mem is over its softlimit.
+                 */
+                if (excess || mz->on_tree) {
+                        spin_lock(&mctz->lock);
+                        /* if on-tree, remove it */
+                        if (mz->on_tree)
+                                __mem_cgroup_remove_exceeded(mem, mz, mctz);
+                        /*
+                         * Insert again. mz->usage_in_excess will be updated.
+                         * If excess is 0, no tree ops.
+                         */
+                        __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
+                        spin_unlock(&mctz->lock);
+                }
+        }
+}
+
+static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
+{
+        int node, zone;
+        struct mem_cgroup_per_zone *mz;
+        struct mem_cgroup_tree_per_zone *mctz;
+
+        for_each_node_state(node, N_POSSIBLE) {
+                for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+                        mz = mem_cgroup_zoneinfo(mem, node, zone);
+                        mctz = soft_limit_tree_node_zone(node, zone);
+                        mem_cgroup_remove_exceeded(mem, mz, mctz);
+                }
+        }
+}
+
+static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
+{
+        return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
+}
+
+static struct mem_cgroup_per_zone *
+__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+        struct rb_node *rightmost = NULL;
+        struct mem_cgroup_per_zone *mz;
+
+retry:
+        mz = NULL;
+        rightmost = rb_last(&mctz->rb_root);
+        if (!rightmost)
+                goto done;              /* Nothing to reclaim from */
+
+        mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
+        /*
+         * Remove the node now but someone else can add it back,
+         * we will to add it back at the end of reclaim to its correct
+         * position in the tree.
+         */
+        __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
+        if (!res_counter_soft_limit_excess(&mz->mem->res) ||
+                !css_tryget(&mz->mem->css))
+                goto retry;
+done:
+        return mz;
+}
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+        struct mem_cgroup_per_zone *mz;
+
+        spin_lock(&mctz->lock);
+        mz = __mem_cgroup_largest_soft_limit_node(mctz);
+        spin_unlock(&mctz->lock);
+        return mz;
+}
+
+static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
+                                         bool charge)
+{
+        int val = (charge) ? 1 : -1;
+        struct mem_cgroup_stat *stat = &mem->stat;
+        struct mem_cgroup_stat_cpu *cpustat;
+        int cpu = get_cpu();
+
+        cpustat = &stat->cpustat[cpu];
+        __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SWAPOUT, val);
+        put_cpu();
+}
+
 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
                                          struct page_cgroup *pc,
                                          bool charge)
 {
-        int val = (charge)? 1 : -1;
+        int val = (charge) ? 1 : -1;
         struct mem_cgroup_stat *stat = &mem->stat;
         struct mem_cgroup_stat_cpu *cpustat;
         int cpu = get_cpu();
@@ -240,28 +509,10 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
         else
                 __mem_cgroup_stat_add_safe(cpustat,
                                 MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
+        __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_EVENTS, 1);
         put_cpu();
 }
 
-static struct mem_cgroup_per_zone *
-mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
-{
-        return &mem->info.nodeinfo[nid]->zoneinfo[zid];
-}
-
-static struct mem_cgroup_per_zone *
-page_cgroup_zoneinfo(struct page_cgroup *pc)
-{
-        struct mem_cgroup *mem = pc->mem_cgroup;
-        int nid = page_cgroup_nid(pc);
-        int zid = page_cgroup_zid(pc);
-
-        if (!mem)
-                return NULL;
-
-        return mem_cgroup_zoneinfo(mem, nid, zid);
-}
-
 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
                                         enum lru_list idx)
 {
@@ -354,6 +605,11 @@ static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data,
         return ret;
 }
 
+static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
+{
+        return (mem == root_mem_cgroup);
+}
+
 /*
  * Following LRU functions are allowed to be used without PCG_LOCK.
  * Operations are called by routine of global LRU independently from memcg.
@@ -371,22 +627,24 @@ static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data,
 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
 {
         struct page_cgroup *pc;
-        struct mem_cgroup *mem;
         struct mem_cgroup_per_zone *mz;
 
         if (mem_cgroup_disabled())
                 return;
         pc = lookup_page_cgroup(page);
         /* can happen while we handle swapcache. */
-        if (list_empty(&pc->lru) || !pc->mem_cgroup)
+        if (!TestClearPageCgroupAcctLRU(pc))
                 return;
+        VM_BUG_ON(!pc->mem_cgroup);
         /*
          * We don't check PCG_USED bit. It's cleared when the "page" is finally
          * removed from global LRU.
          */
         mz = page_cgroup_zoneinfo(pc);
-        mem = pc->mem_cgroup;
         MEM_CGROUP_ZSTAT(mz, lru) -= 1;
+        if (mem_cgroup_is_root(pc->mem_cgroup))
+                return;
+        VM_BUG_ON(list_empty(&pc->lru));
         list_del_init(&pc->lru);
         return;
 }
@@ -410,8 +668,8 @@ void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
          * For making pc->mem_cgroup visible, insert smp_rmb() here.
          */
         smp_rmb();
-        /* unused page is not rotated. */
-        if (!PageCgroupUsed(pc))
+        /* unused or root page is not rotated. */
+        if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup))
                 return;
         mz = page_cgroup_zoneinfo(pc);
         list_move(&pc->lru, &mz->lists[lru]);
@@ -425,6 +683,7 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
         if (mem_cgroup_disabled())
                 return;
         pc = lookup_page_cgroup(page);
+        VM_BUG_ON(PageCgroupAcctLRU(pc));
         /*
          * Used bit is set without atomic ops but after smp_wmb().
          * For making pc->mem_cgroup visible, insert smp_rmb() here.
@@ -435,6 +694,9 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 
         mz = page_cgroup_zoneinfo(pc);
         MEM_CGROUP_ZSTAT(mz, lru) += 1;
+        SetPageCgroupAcctLRU(pc);
+        if (mem_cgroup_is_root(pc->mem_cgroup))
+                return;
         list_add(&pc->lru, &mz->lists[lru]);
 }
 
@@ -469,7 +731,7 @@ static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
 
         spin_lock_irqsave(&zone->lru_lock, flags);
         /* link when the page is linked to LRU but page_cgroup isn't */
-        if (PageLRU(page) && list_empty(&pc->lru))
+        if (PageLRU(page) && !PageCgroupAcctLRU(pc))
                 mem_cgroup_add_lru_list(page, page_lru(page));
         spin_unlock_irqrestore(&zone->lru_lock, flags);
 }
@@ -648,7 +910,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
         int nid = z->zone_pgdat->node_id;
         int zid = zone_idx(z);
         struct mem_cgroup_per_zone *mz;
-        int lru = LRU_FILE * !!file + !!active;
+        int lru = LRU_FILE * file + active;
         int ret;
 
         BUG_ON(!mem_cont);
@@ -855,28 +1117,62 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
  * If shrink==true, for avoiding to free too much, this returns immedieately.
  */
 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
-                                   gfp_t gfp_mask, bool noswap, bool shrink)
+                                                struct zone *zone,
+                                                gfp_t gfp_mask,
+                                                unsigned long reclaim_options)
 {
         struct mem_cgroup *victim;
         int ret, total = 0;
         int loop = 0;
+        bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
+        bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
+        bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
+        unsigned long excess = mem_cgroup_get_excess(root_mem);
 
         /* If memsw_is_minimum==1, swap-out is of-no-use. */
         if (root_mem->memsw_is_minimum)
                 noswap = true;
 
-        while (loop < 2) {
+        while (1) {
                 victim = mem_cgroup_select_victim(root_mem);
-                if (victim == root_mem)
+                if (victim == root_mem) {
                         loop++;
+                        if (loop >= 2) {
+                                /*
+                                 * If we have not been able to reclaim
+                                 * anything, it might because there are
+                                 * no reclaimable pages under this hierarchy
+                                 */
+                                if (!check_soft || !total) {
+                                        css_put(&victim->css);
+                                        break;
+                                }
+                                /*
+                                 * We want to do more targetted reclaim.
+                                 * excess >> 2 is not to excessive so as to
+                                 * reclaim too much, nor too less that we keep
+                                 * coming back to reclaim from this cgroup
+                                 */
+                                if (total >= (excess >> 2) ||
+                                        (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
+                                        css_put(&victim->css);
+                                        break;
+                                }
+                        }
+                }
                 if (!mem_cgroup_local_usage(&victim->stat)) {
                         /* this cgroup's local usage == 0 */
                         css_put(&victim->css);
                         continue;
                 }
                 /* we use swappiness of local cgroup */
-                ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap,
-                                                   get_swappiness(victim));
+                if (check_soft)
+                        ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
+                                noswap, get_swappiness(victim), zone,
+                                zone->zone_pgdat->node_id);
+                else
+                        ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
+                                                noswap, get_swappiness(victim));
                 css_put(&victim->css);
                 /*
                  * At shrinking usage, we can't check we should stop here or
@@ -886,7 +1182,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
                 if (shrink)
                         return ret;
                 total += ret;
-                if (mem_cgroup_check_under_limit(root_mem))
+                if (check_soft) {
+                        if (res_counter_check_under_soft_limit(&root_mem->res))
+                                return total;
+                } else if (mem_cgroup_check_under_limit(root_mem))
                         return 1 + total;
         }
         return total;
@@ -965,7 +1264,7 @@ done:
  */
 static int __mem_cgroup_try_charge(struct mm_struct *mm,
                         gfp_t gfp_mask, struct mem_cgroup **memcg,
-                        bool oom)
+                        bool oom, struct page *page)
 {
         struct mem_cgroup *mem, *mem_over_limit;
         int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
@@ -996,9 +1295,11 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
         VM_BUG_ON(css_is_removed(&mem->css));
 
         while (1) {
-                int ret;
-                bool noswap = false;
+                int ret = 0;
+                unsigned long flags = 0;
 
+                if (mem_cgroup_is_root(mem))
+                        goto done;
                 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
                 if (likely(!ret)) {
                         if (!do_swap_account)
@@ -1009,7 +1310,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                                 break;
                         /* mem+swap counter fails */
                         res_counter_uncharge(&mem->res, PAGE_SIZE);
-                        noswap = true;
+                        flags |= MEM_CGROUP_RECLAIM_NOSWAP;
                         mem_over_limit = mem_cgroup_from_res_counter(fail_res,
                                                                         memsw);
                 } else
@@ -1020,8 +1321,8 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                 if (!(gfp_mask & __GFP_WAIT))
                         goto nomem;
 
-                ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
-                                                        noswap, false);
+                ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
+                                                gfp_mask, flags);
                 if (ret)
                         continue;
 
@@ -1046,13 +1347,19 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                         goto nomem;
                 }
         }
+        /*
+         * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
+         * if they exceeds softlimit.
+         */
+        if (mem_cgroup_soft_limit_check(mem))
+                mem_cgroup_update_tree(mem, page);
+done:
         return 0;
 nomem:
         css_put(&mem->css);
         return -ENOMEM;
 }
 
-
 /*
  * A helper function to get mem_cgroup from ID. must be called under
  * rcu_read_lock(). The caller must check css_is_removed() or some if
@@ -1119,15 +1426,37 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
         lock_page_cgroup(pc);
         if (unlikely(PageCgroupUsed(pc))) {
                 unlock_page_cgroup(pc);
-                res_counter_uncharge(&mem->res, PAGE_SIZE);
-                if (do_swap_account)
-                        res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+                if (!mem_cgroup_is_root(mem)) {
+                        res_counter_uncharge(&mem->res, PAGE_SIZE);
+                        if (do_swap_account)
+                                res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+                }
                 css_put(&mem->css);
                 return;
         }
+
         pc->mem_cgroup = mem;
+        /*
+         * We access a page_cgroup asynchronously without lock_page_cgroup().
+         * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
+         * is accessed after testing USED bit. To make pc->mem_cgroup visible
+         * before USED bit, we need memory barrier here.
+         * See mem_cgroup_add_lru_list(), etc.
+         */
         smp_wmb();
-        pc->flags = pcg_default_flags[ctype];
+        switch (ctype) {
+        case MEM_CGROUP_CHARGE_TYPE_CACHE:
+        case MEM_CGROUP_CHARGE_TYPE_SHMEM:
+                SetPageCgroupCache(pc);
+                SetPageCgroupUsed(pc);
+                break;
+        case MEM_CGROUP_CHARGE_TYPE_MAPPED:
+                ClearPageCgroupCache(pc);
+                SetPageCgroupUsed(pc);
+                break;
+        default:
+                break;
+        }
 
         mem_cgroup_charge_statistics(mem, pc, true);
 
@@ -1178,7 +1507,8 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
         if (pc->mem_cgroup != from)
                 goto out;
 
-        res_counter_uncharge(&from->res, PAGE_SIZE);
+        if (!mem_cgroup_is_root(from))
+                res_counter_uncharge(&from->res, PAGE_SIZE);
         mem_cgroup_charge_statistics(from, pc, false);
 
         page = pc->page;
@@ -1197,7 +1527,7 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
                                                 1);
         }
 
-        if (do_swap_account)
+        if (do_swap_account && !mem_cgroup_is_root(from))
                 res_counter_uncharge(&from->memsw, PAGE_SIZE);
         css_put(&from->css);
 
@@ -1238,7 +1568,7 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc,
         parent = mem_cgroup_from_cont(pcg);
 
 
-        ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
+        ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, page);
         if (ret || !parent)
                 return ret;
 
@@ -1268,9 +1598,11 @@ uncharge:
         /* drop extra refcnt by try_charge() */
         css_put(&parent->css);
         /* uncharge if move fails */
-        res_counter_uncharge(&parent->res, PAGE_SIZE);
-        if (do_swap_account)
-                res_counter_uncharge(&parent->memsw, PAGE_SIZE);
+        if (!mem_cgroup_is_root(parent)) {
+                res_counter_uncharge(&parent->res, PAGE_SIZE);
+                if (do_swap_account)
+                        res_counter_uncharge(&parent->memsw, PAGE_SIZE);
+        }
         return ret;
 }
 
@@ -1295,7 +1627,7 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
         prefetchw(pc);
 
         mem = memcg;
-        ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
+        ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page);
         if (ret || !mem)
                 return ret;
 
@@ -1414,14 +1746,14 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
         if (!mem)
                 goto charge_cur_mm;
         *ptr = mem;
-        ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
+        ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, page);
         /* drop extra refcnt from tryget */
         css_put(&mem->css);
         return ret;
 charge_cur_mm:
         if (unlikely(!mm))
                 mm = &init_mm;
-        return __mem_cgroup_try_charge(mm, mask, ptr, true);
+        return __mem_cgroup_try_charge(mm, mask, ptr, true, page);
 }
 
 static void
@@ -1459,7 +1791,9 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
                          * This recorded memcg can be obsolete one. So, avoid
                          * calling css_tryget
                          */
-                        res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+                        if (!mem_cgroup_is_root(memcg))
+                                res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+                        mem_cgroup_swap_statistics(memcg, false);
                         mem_cgroup_put(memcg);
                 }
                 rcu_read_unlock();
@@ -1484,9 +1818,11 @@ void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
                 return;
         if (!mem)
                 return;
-        res_counter_uncharge(&mem->res, PAGE_SIZE);
-        if (do_swap_account)
-                res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+        if (!mem_cgroup_is_root(mem)) {
+                res_counter_uncharge(&mem->res, PAGE_SIZE);
+                if (do_swap_account)
+                        res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+        }
         css_put(&mem->css);
 }
 
@@ -1538,9 +1874,14 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
                 break;
         }
 
-        res_counter_uncharge(&mem->res, PAGE_SIZE);
-        if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
-                res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+        if (!mem_cgroup_is_root(mem)) {
+                res_counter_uncharge(&mem->res, PAGE_SIZE);
+                if (do_swap_account &&
+                                (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
+                        res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+        }
+        if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
+                mem_cgroup_swap_statistics(mem, true);
         mem_cgroup_charge_statistics(mem, pc, false);
 
         ClearPageCgroupUsed(pc);
@@ -1554,6 +1895,8 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
         mz = page_cgroup_zoneinfo(pc);
         unlock_page_cgroup(pc);
 
+        if (mem_cgroup_soft_limit_check(mem))
+                mem_cgroup_update_tree(mem, page);
         /* at swapout, this memcg will be accessed to record to swap */
         if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
                 css_put(&mem->css);
@@ -1629,7 +1972,9 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent)
                  * We uncharge this because swap is freed.
                  * This memcg can be obsolete one. We avoid calling css_tryget
                  */
-                res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+                if (!mem_cgroup_is_root(memcg))
+                        res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+                mem_cgroup_swap_statistics(memcg, false);
                 mem_cgroup_put(memcg);
         }
         rcu_read_unlock();
@@ -1658,7 +2003,8 @@ int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
         unlock_page_cgroup(pc);
 
         if (mem) {
-                ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
+                ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
+                                                page);
                 css_put(&mem->css);
         }
         *ptr = mem;
@@ -1798,8 +2144,9 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                 if (!ret)
                         break;
 
-                progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL,
-                                                   false, true);
+                progress = mem_cgroup_hierarchical_reclaim(memcg, NULL,
+                                                GFP_KERNEL,
+                                                MEM_CGROUP_RECLAIM_SHRINK);
                 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
                 /* Usage is reduced ? */
                 if (curusage >= oldusage)
@@ -1851,7 +2198,9 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
                 if (!ret)
                         break;
 
-                mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true, true);
+                mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
+                                                MEM_CGROUP_RECLAIM_NOSWAP |
+                                                MEM_CGROUP_RECLAIM_SHRINK);
                 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
                 /* Usage is reduced ? */
                 if (curusage >= oldusage)
@@ -1862,6 +2211,97 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
         return ret;
 }
 
+unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
+                                                gfp_t gfp_mask, int nid,
+                                                int zid)
+{
+        unsigned long nr_reclaimed = 0;
+        struct mem_cgroup_per_zone *mz, *next_mz = NULL;
+        unsigned long reclaimed;
+        int loop = 0;
+        struct mem_cgroup_tree_per_zone *mctz;
+        unsigned long long excess;
+
+        if (order > 0)
+                return 0;
+
+        mctz = soft_limit_tree_node_zone(nid, zid);
+        /*
+         * This loop can run a while, specially if mem_cgroup's continuously
+         * keep exceeding their soft limit and putting the system under
+         * pressure
+         */
+        do {
+                if (next_mz)
+                        mz = next_mz;
+                else
+                        mz = mem_cgroup_largest_soft_limit_node(mctz);
+                if (!mz)
+                        break;
+
+                reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
+                                                gfp_mask,
+                                                MEM_CGROUP_RECLAIM_SOFT);
+                nr_reclaimed += reclaimed;
+                spin_lock(&mctz->lock);
+
+                /*
+                 * If we failed to reclaim anything from this memory cgroup
+                 * it is time to move on to the next cgroup
+                 */
+                next_mz = NULL;
+                if (!reclaimed) {
+                        do {
+                                /*
+                                 * Loop until we find yet another one.
+                                 *
+                                 * By the time we get the soft_limit lock
+                                 * again, someone might have aded the
+                                 * group back on the RB tree. Iterate to
+                                 * make sure we get a different mem.
+                                 * mem_cgroup_largest_soft_limit_node returns
+                                 * NULL if no other cgroup is present on
+                                 * the tree
+                                 */
+                                next_mz =
+                                __mem_cgroup_largest_soft_limit_node(mctz);
+                                if (next_mz == mz) {
+                                        css_put(&next_mz->mem->css);
+                                        next_mz = NULL;
+                                } else /* next_mz == NULL or other memcg */
+                                        break;
+                        } while (1);
+                }
+                __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
+                excess = res_counter_soft_limit_excess(&mz->mem->res);
+                /*
+                 * One school of thought says that we should not add
+                 * back the node to the tree if reclaim returns 0.
+                 * But our reclaim could return 0, simply because due
+                 * to priority we are exposing a smaller subset of
+                 * memory to reclaim from. Consider this as a longer
+                 * term TODO.
+                 */
+                /* If excess == 0, no tree ops */
+                __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
+                spin_unlock(&mctz->lock);
+                css_put(&mz->mem->css);
+                loop++;
+                /*
+                 * Could not reclaim anything and there are no more
+                 * mem cgroups to try or we seem to be looping without
+                 * reclaiming anything.
+                 */
+                if (!nr_reclaimed &&
+                        (next_mz == NULL ||
+                        loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
+                        break;
+        } while (!nr_reclaimed);
+        if (next_mz)
+                css_put(&next_mz->mem->css);
+        return nr_reclaimed;
+}
+
 /*
  * This routine traverse page_cgroup in given list and drop them all.
  * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
@@ -2046,20 +2486,64 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
         return retval;
 }
 
+struct mem_cgroup_idx_data {
+        s64 val;
+        enum mem_cgroup_stat_index idx;
+};
+
+static int
+mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data)
+{
+        struct mem_cgroup_idx_data *d = data;
+        d->val += mem_cgroup_read_stat(&mem->stat, d->idx);
+        return 0;
+}
+
+static void
+mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
+                                enum mem_cgroup_stat_index idx, s64 *val)
+{
+        struct mem_cgroup_idx_data d;
+        d.idx = idx;
+        d.val = 0;
+        mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat);
+        *val = d.val;
+}
+
 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
 {
         struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
-        u64 val = 0;
+        u64 idx_val, val;
         int type, name;
 
         type = MEMFILE_TYPE(cft->private);
         name = MEMFILE_ATTR(cft->private);
         switch (type) {
         case _MEM:
-                val = res_counter_read_u64(&mem->res, name);
+                if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_CACHE, &idx_val);
+                        val = idx_val;
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_RSS, &idx_val);
+                        val += idx_val;
+                        val <<= PAGE_SHIFT;
+                } else
+                        val = res_counter_read_u64(&mem->res, name);
                 break;
         case _MEMSWAP:
-                val = res_counter_read_u64(&mem->memsw, name);
+                if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_CACHE, &idx_val);
+                        val = idx_val;
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_RSS, &idx_val);
+                        val += idx_val;
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_SWAPOUT, &idx_val);
+                        val <<= PAGE_SHIFT;
+                } else
+                        val = res_counter_read_u64(&mem->memsw, name);
                 break;
         default:
                 BUG();
@@ -2083,6 +2567,10 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
         name = MEMFILE_ATTR(cft->private);
         switch (name) {
         case RES_LIMIT:
+                if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
+                        ret = -EINVAL;
+                        break;
+                }
                 /* This function does all necessary parse...reuse it */
                 ret = res_counter_memparse_write_strategy(buffer, &val);
                 if (ret)
@@ -2092,6 +2580,20 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
                 else
                         ret = mem_cgroup_resize_memsw_limit(memcg, val);
                 break;
+        case RES_SOFT_LIMIT:
+                ret = res_counter_memparse_write_strategy(buffer, &val);
+                if (ret)
+                        break;
+                /*
+                 * For memsw, soft limits are hard to implement in terms
+                 * of semantics, for now, we support soft limits for
+                 * control without swap
+                 */
+                if (type == _MEM)
+                        ret = res_counter_set_soft_limit(&memcg->res, val);
+                else
+                        ret = -EINVAL;
+                break;
         default:
                 ret = -EINVAL; /* should be BUG() ? */
                 break;
@@ -2149,6 +2651,7 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
                         res_counter_reset_failcnt(&mem->memsw);
                 break;
         }
+
         return 0;
 }
 
@@ -2160,6 +2663,7 @@ enum {
         MCS_MAPPED_FILE,
         MCS_PGPGIN,
         MCS_PGPGOUT,
+        MCS_SWAP,
         MCS_INACTIVE_ANON,
         MCS_ACTIVE_ANON,
         MCS_INACTIVE_FILE,
@@ -2181,6 +2685,7 @@ struct {
         {"mapped_file", "total_mapped_file"},
         {"pgpgin", "total_pgpgin"},
         {"pgpgout", "total_pgpgout"},
+        {"swap", "total_swap"},
         {"inactive_anon", "total_inactive_anon"},
         {"active_anon", "total_active_anon"},
         {"inactive_file", "total_inactive_file"},
@@ -2205,6 +2710,10 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
         s->stat[MCS_PGPGIN] += val;
         val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);
         s->stat[MCS_PGPGOUT] += val;
+        if (do_swap_account) {
+                val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_SWAPOUT);
+                s->stat[MCS_SWAP] += val * PAGE_SIZE;
+        }
 
         /* per zone stat */
         val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
@@ -2236,8 +2745,11 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
         memset(&mystat, 0, sizeof(mystat));
         mem_cgroup_get_local_stat(mem_cont, &mystat);
 
-        for (i = 0; i < NR_MCS_STAT; i++)
+        for (i = 0; i < NR_MCS_STAT; i++) {
+                if (i == MCS_SWAP && !do_swap_account)
+                        continue;
                 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
+        }
 
         /* Hierarchical information */
         {
@@ -2250,9 +2762,11 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
 
         memset(&mystat, 0, sizeof(mystat));
         mem_cgroup_get_total_stat(mem_cont, &mystat);
-        for (i = 0; i < NR_MCS_STAT; i++)
+        for (i = 0; i < NR_MCS_STAT; i++) {
+                if (i == MCS_SWAP && !do_swap_account)
+                        continue;
                 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
-
+        }
 
 #ifdef CONFIG_DEBUG_VM
         cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
@@ -2345,6 +2859,12 @@ static struct cftype mem_cgroup_files[] = {
                 .read_u64 = mem_cgroup_read,
         },
         {
+                .name = "soft_limit_in_bytes",
+                .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
+                .write_string = mem_cgroup_write,
+                .read_u64 = mem_cgroup_read,
+        },
+        {
                 .name = "failcnt",
                 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
                 .trigger = mem_cgroup_reset,
@@ -2438,6 +2958,9 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
                 mz = &pn->zoneinfo[zone];
                 for_each_lru(l)
                         INIT_LIST_HEAD(&mz->lists[l]);
+                mz->usage_in_excess = 0;
+                mz->on_tree = false;
+                mz->mem = mem;
         }
         return 0;
 }
@@ -2483,6 +3006,7 @@ static void __mem_cgroup_free(struct mem_cgroup *mem)
 {
         int node;
 
+        mem_cgroup_remove_from_trees(mem);
         free_css_id(&mem_cgroup_subsys, &mem->css);
 
         for_each_node_state(node, N_POSSIBLE)
@@ -2531,6 +3055,31 @@ static void __init enable_swap_cgroup(void)
 }
 #endif
 
+static int mem_cgroup_soft_limit_tree_init(void)
+{
+        struct mem_cgroup_tree_per_node *rtpn;
+        struct mem_cgroup_tree_per_zone *rtpz;
+        int tmp, node, zone;
+
+        for_each_node_state(node, N_POSSIBLE) {
+                tmp = node;
+                if (!node_state(node, N_NORMAL_MEMORY))
+                        tmp = -1;
+                rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
+                if (!rtpn)
+                        return 1;
+
+                soft_limit_tree.rb_tree_per_node[node] = rtpn;
+
+                for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+                        rtpz = &rtpn->rb_tree_per_zone[zone];
+                        rtpz->rb_root = RB_ROOT;
+                        spin_lock_init(&rtpz->lock);
+                }
+        }
+        return 0;
+}
+
 static struct cgroup_subsys_state * __ref
 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 {
@@ -2545,10 +3094,15 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
         for_each_node_state(node, N_POSSIBLE)
                 if (alloc_mem_cgroup_per_zone_info(mem, node))
                         goto free_out;
+
         /* root ? */
         if (cont->parent == NULL) {
                 enable_swap_cgroup();
                 parent = NULL;
+                root_mem_cgroup = mem;
+                if (mem_cgroup_soft_limit_tree_init())
+                        goto free_out;
+
         } else {
                 parent = mem_cgroup_from_cont(cont->parent);
                 mem->use_hierarchy = parent->use_hierarchy;
@@ -2577,6 +3131,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
         return &mem->css;
 free_out:
         __mem_cgroup_free(mem);
+        root_mem_cgroup = NULL;
         return ERR_PTR(error);
 }
 
@@ -2612,7 +3167,8 @@ static int mem_cgroup_populate(struct cgroup_subsys *ss,
 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
                                 struct cgroup *cont,
                                 struct cgroup *old_cont,
-                                struct task_struct *p)
+                                struct task_struct *p,
+                                bool threadgroup)
 {
         mutex_lock(&memcg_tasklist);
         /*
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
new file mode 100644
index 000000000000..729d4b15b645
--- /dev/null
+++ b/mm/memory-failure.c
@@ -0,0 +1,832 @@
+/*
+ * Copyright (C) 2008, 2009 Intel Corporation
+ * Authors: Andi Kleen, Fengguang Wu
+ *
+ * This software may be redistributed and/or modified under the terms of
+ * the GNU General Public License ("GPL") version 2 only as published by the
+ * Free Software Foundation.
+ *
+ * High level machine check handler. Handles pages reported by the
+ * hardware as being corrupted usually due to a 2bit ECC memory or cache
+ * failure.
+ *
+ * Handles page cache pages in various states.  The tricky part
+ * here is that we can access any page asynchronous to other VM
+ * users, because memory failures could happen anytime and anywhere,
+ * possibly violating some of their assumptions. This is why this code
+ * has to be extremely careful. Generally it tries to use normal locking
+ * rules, as in get the standard locks, even if that means the
+ * error handling takes potentially a long time.
+ *
+ * The operation to map back from RMAP chains to processes has to walk
+ * the complete process list and has non linear complexity with the number
+ * mappings. In short it can be quite slow. But since memory corruptions
+ * are rare we hope to get away with this.
+ */
+
+/*
+ * Notebook:
+ * - hugetlb needs more code
+ * - kcore/oldmem/vmcore/mem/kmem check for hwpoison pages
+ * - pass bad pages to kdump next kernel
+ */
+#define DEBUG 1         /* remove me in 2.6.34 */
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/page-flags.h>
+#include <linux/sched.h>
+#include <linux/rmap.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/backing-dev.h>
+#include "internal.h"
+
+int sysctl_memory_failure_early_kill __read_mostly = 0;
+
+int sysctl_memory_failure_recovery __read_mostly = 1;
+
+atomic_long_t mce_bad_pages __read_mostly = ATOMIC_LONG_INIT(0);
+
+/*
+ * Send all the processes who have the page mapped an ``action optional''
+ * signal.
+ */
+static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno,
+                        unsigned long pfn)
+{
+        struct siginfo si;
+        int ret;
+
+        printk(KERN_ERR
+                "MCE %#lx: Killing %s:%d early due to hardware memory corruption\n",
+                pfn, t->comm, t->pid);
+        si.si_signo = SIGBUS;
+        si.si_errno = 0;
+        si.si_code = BUS_MCEERR_AO;
+        si.si_addr = (void *)addr;
+#ifdef __ARCH_SI_TRAPNO
+        si.si_trapno = trapno;
+#endif
+        si.si_addr_lsb = PAGE_SHIFT;
+        /*
+         * Don't use force here, it's convenient if the signal
+         * can be temporarily blocked.
+         * This could cause a loop when the user sets SIGBUS
+         * to SIG_IGN, but hopefully noone will do that?
+         */
+        ret = send_sig_info(SIGBUS, &si, t);  /* synchronous? */
+        if (ret < 0)
+                printk(KERN_INFO "MCE: Error sending signal to %s:%d: %d\n",
+                       t->comm, t->pid, ret);
+        return ret;
+}
+
+/*
+ * Kill all processes that have a poisoned page mapped and then isolate
+ * the page.
+ *
+ * General strategy:
+ * Find all processes having the page mapped and kill them.
+ * But we keep a page reference around so that the page is not
+ * actually freed yet.
+ * Then stash the page away
+ *
+ * There's no convenient way to get back to mapped processes
+ * from the VMAs. So do a brute-force search over all
+ * running processes.
+ *
+ * Remember that machine checks are not common (or rather
+ * if they are common you have other problems), so this shouldn't
+ * be a performance issue.
+ *
+ * Also there are some races possible while we get from the
+ * error detection to actually handle it.
+ */
+
+struct to_kill {
+        struct list_head nd;
+        struct task_struct *tsk;
+        unsigned long addr;
+        unsigned addr_valid:1;
+};
+
+/*
+ * Failure handling: if we can't find or can't kill a process there's
+ * not much we can do.  We just print a message and ignore otherwise.
+ */
+
+/*
+ * Schedule a process for later kill.
+ * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
+ * TBD would GFP_NOIO be enough?
+ */
+static void add_to_kill(struct task_struct *tsk, struct page *p,
+                       struct vm_area_struct *vma,
+                       struct list_head *to_kill,
+                       struct to_kill **tkc)
+{
+        struct to_kill *tk;
+
+        if (*tkc) {
+                tk = *tkc;
+                *tkc = NULL;
+        } else {
+                tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC);
+                if (!tk) {
+                        printk(KERN_ERR
+                "MCE: Out of memory while machine check handling\n");
+                        return;
+                }
+        }
+        tk->addr = page_address_in_vma(p, vma);
+        tk->addr_valid = 1;
+
+        /*
+         * In theory we don't have to kill when the page was
+         * munmaped. But it could be also a mremap. Since that's
+         * likely very rare kill anyways just out of paranoia, but use
+         * a SIGKILL because the error is not contained anymore.
+         */
+        if (tk->addr == -EFAULT) {
+                pr_debug("MCE: Unable to find user space address %lx in %s\n",
+                        page_to_pfn(p), tsk->comm);
+                tk->addr_valid = 0;
+        }
+        get_task_struct(tsk);
+        tk->tsk = tsk;
+        list_add_tail(&tk->nd, to_kill);
+}
+
+/*
+ * Kill the processes that have been collected earlier.
+ *
+ * Only do anything when DOIT is set, otherwise just free the list
+ * (this is used for clean pages which do not need killing)
+ * Also when FAIL is set do a force kill because something went
+ * wrong earlier.
+ */
+static void kill_procs_ao(struct list_head *to_kill, int doit, int trapno,
+                          int fail, unsigned long pfn)
+{
+        struct to_kill *tk, *next;
+
+        list_for_each_entry_safe (tk, next, to_kill, nd) {
+                if (doit) {
+                        /*
+                         * In case something went wrong with munmaping
+                         * make sure the process doesn't catch the
+                         * signal and then access the memory. Just kill it.
+                         * the signal handlers
+                         */
+                        if (fail || tk->addr_valid == 0) {
+                                printk(KERN_ERR
+                "MCE %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
+                                        pfn, tk->tsk->comm, tk->tsk->pid);
+                                force_sig(SIGKILL, tk->tsk);
+                        }
+
+                        /*
+                         * In theory the process could have mapped
+                         * something else on the address in-between. We could
+                         * check for that, but we need to tell the
+                         * process anyways.
+                         */
+                        else if (kill_proc_ao(tk->tsk, tk->addr, trapno,
+                                              pfn) < 0)
+                                printk(KERN_ERR
+                "MCE %#lx: Cannot send advisory machine check signal to %s:%d\n",
+                                        pfn, tk->tsk->comm, tk->tsk->pid);
+                }
+                put_task_struct(tk->tsk);
+                kfree(tk);
+        }
+}
+
+static int task_early_kill(struct task_struct *tsk)
+{
+        if (!tsk->mm)
+                return 0;
+        if (tsk->flags & PF_MCE_PROCESS)
+                return !!(tsk->flags & PF_MCE_EARLY);
+        return sysctl_memory_failure_early_kill;
+}
+
+/*
+ * Collect processes when the error hit an anonymous page.
+ */
+static void collect_procs_anon(struct page *page, struct list_head *to_kill,
+                              struct to_kill **tkc)
+{
+        struct vm_area_struct *vma;
+        struct task_struct *tsk;
+        struct anon_vma *av;
+
+        read_lock(&tasklist_lock);
+        av = page_lock_anon_vma(page);
+        if (av == NULL) /* Not actually mapped anymore */
+                goto out;
+        for_each_process (tsk) {
+                if (!task_early_kill(tsk))
+                        continue;
+                list_for_each_entry (vma, &av->head, anon_vma_node) {
+                        if (!page_mapped_in_vma(page, vma))
+                                continue;
+                        if (vma->vm_mm == tsk->mm)
+                                add_to_kill(tsk, page, vma, to_kill, tkc);
+                }
+        }
+        page_unlock_anon_vma(av);
+out:
+        read_unlock(&tasklist_lock);
+}
+
+/*
+ * Collect processes when the error hit a file mapped page.
+ */
+static void collect_procs_file(struct page *page, struct list_head *to_kill,
+                              struct to_kill **tkc)
+{
+        struct vm_area_struct *vma;
+        struct task_struct *tsk;
+        struct prio_tree_iter iter;
+        struct address_space *mapping = page->mapping;
+
+        /*
+         * A note on the locking order between the two locks.
+         * We don't rely on this particular order.
+         * If you have some other code that needs a different order
+         * feel free to switch them around. Or add a reverse link
+         * from mm_struct to task_struct, then this could be all
+         * done without taking tasklist_lock and looping over all tasks.
+         */
+
+        read_lock(&tasklist_lock);
+        spin_lock(&mapping->i_mmap_lock);
+        for_each_process(tsk) {
+                pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+
+                if (!task_early_kill(tsk))
+                        continue;
+
+                vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff,
+                                      pgoff) {
+                        /*
+                         * Send early kill signal to tasks where a vma covers
+                         * the page but the corrupted page is not necessarily
+                         * mapped it in its pte.
+                         * Assume applications who requested early kill want
+                         * to be informed of all such data corruptions.
+                         */
+                        if (vma->vm_mm == tsk->mm)
+                                add_to_kill(tsk, page, vma, to_kill, tkc);
+                }
+        }
+        spin_unlock(&mapping->i_mmap_lock);
+        read_unlock(&tasklist_lock);
+}
+
+/*
+ * Collect the processes who have the corrupted page mapped to kill.
+ * This is done in two steps for locking reasons.
+ * First preallocate one tokill structure outside the spin locks,
+ * so that we can kill at least one process reasonably reliable.
+ */
+static void collect_procs(struct page *page, struct list_head *tokill)
+{
+        struct to_kill *tk;
+
+        if (!page->mapping)
+                return;
+
+        tk = kmalloc(sizeof(struct to_kill), GFP_NOIO);
+        if (!tk)
+                return;
+        if (PageAnon(page))
+                collect_procs_anon(page, tokill, &tk);
+        else
+                collect_procs_file(page, tokill, &tk);
+        kfree(tk);
+}
+
+/*
+ * Error handlers for various types of pages.
+ */
+
+enum outcome {
+        FAILED,         /* Error handling failed */
+        DELAYED,        /* Will be handled later */
+        IGNORED,        /* Error safely ignored */
+        RECOVERED,      /* Successfully recovered */
+};
+
+static const char *action_name[] = {
+        [FAILED] = "Failed",
+        [DELAYED] = "Delayed",
+        [IGNORED] = "Ignored",
+        [RECOVERED] = "Recovered",
+};
+
+/*
+ * Error hit kernel page.
+ * Do nothing, try to be lucky and not touch this instead. For a few cases we
+ * could be more sophisticated.
+ */
+static int me_kernel(struct page *p, unsigned long pfn)
+{
+        return DELAYED;
+}
+
+/*
+ * Already poisoned page.
+ */
+static int me_ignore(struct page *p, unsigned long pfn)
+{
+        return IGNORED;
+}
+
+/*
+ * Page in unknown state. Do nothing.
+ */
+static int me_unknown(struct page *p, unsigned long pfn)
+{
+        printk(KERN_ERR "MCE %#lx: Unknown page state\n", pfn);
+        return FAILED;
+}
+
+/*
+ * Free memory
+ */
+static int me_free(struct page *p, unsigned long pfn)
+{
+        return DELAYED;
+}
+
+/*
+ * Clean (or cleaned) page cache page.
+ */
+static int me_pagecache_clean(struct page *p, unsigned long pfn)
+{
+        int err;
+        int ret = FAILED;
+        struct address_space *mapping;
+
+        if (!isolate_lru_page(p))
+                page_cache_release(p);
+
+        /*
+         * For anonymous pages we're done the only reference left
+         * should be the one m_f() holds.
+         */
+        if (PageAnon(p))
+                return RECOVERED;
+
+        /*
+         * Now truncate the page in the page cache. This is really
+         * more like a "temporary hole punch"
+         * Don't do this for block devices when someone else
+         * has a reference, because it could be file system metadata
+         * and that's not safe to truncate.
+         */
+        mapping = page_mapping(p);
+        if (!mapping) {
+                /*
+                 * Page has been teared down in the meanwhile
+                 */
+                return FAILED;
+        }
+
+        /*
+         * Truncation is a bit tricky. Enable it per file system for now.
+         *
+         * Open: to take i_mutex or not for this? Right now we don't.
+         */
+        if (mapping->a_ops->error_remove_page) {
+                err = mapping->a_ops->error_remove_page(mapping, p);
+                if (err != 0) {
+                        printk(KERN_INFO "MCE %#lx: Failed to punch page: %d\n",
+                                        pfn, err);
+                } else if (page_has_private(p) &&
+                                !try_to_release_page(p, GFP_NOIO)) {
+                        pr_debug("MCE %#lx: failed to release buffers\n", pfn);
+                } else {
+                        ret = RECOVERED;
+                }
+        } else {
+                /*
+                 * If the file system doesn't support it just invalidate
+                 * This fails on dirty or anything with private pages
+                 */
+                if (invalidate_inode_page(p))
+                        ret = RECOVERED;
+                else
+                        printk(KERN_INFO "MCE %#lx: Failed to invalidate\n",
+                                pfn);
+        }
+        return ret;
+}
+
+/*
+ * Dirty cache page page
+ * Issues: when the error hit a hole page the error is not properly
+ * propagated.
+ */
+static int me_pagecache_dirty(struct page *p, unsigned long pfn)
+{
+        struct address_space *mapping = page_mapping(p);
+
+        SetPageError(p);
+        /* TBD: print more information about the file. */
+        if (mapping) {
+                /*
+                 * IO error will be reported by write(), fsync(), etc.
+                 * who check the mapping.
+                 * This way the application knows that something went
+                 * wrong with its dirty file data.
+                 *
+                 * There's one open issue:
+                 *
+                 * The EIO will be only reported on the next IO
+                 * operation and then cleared through the IO map.
+                 * Normally Linux has two mechanisms to pass IO error
+                 * first through the AS_EIO flag in the address space
+                 * and then through the PageError flag in the page.
+                 * Since we drop pages on memory failure handling the
+                 * only mechanism open to use is through AS_AIO.
+                 *
+                 * This has the disadvantage that it gets cleared on
+                 * the first operation that returns an error, while
+                 * the PageError bit is more sticky and only cleared
+                 * when the page is reread or dropped.  If an
+                 * application assumes it will always get error on
+                 * fsync, but does other operations on the fd before
+                 * and the page is dropped inbetween then the error
+                 * will not be properly reported.
+                 *
+                 * This can already happen even without hwpoisoned
+                 * pages: first on metadata IO errors (which only
+                 * report through AS_EIO) or when the page is dropped
+                 * at the wrong time.
+                 *
+                 * So right now we assume that the application DTRT on
+                 * the first EIO, but we're not worse than other parts
+                 * of the kernel.
+                 */
+                mapping_set_error(mapping, EIO);
+        }
+
+        return me_pagecache_clean(p, pfn);
+}
+
+/*
+ * Clean and dirty swap cache.
+ *
+ * Dirty swap cache page is tricky to handle. The page could live both in page
+ * cache and swap cache(ie. page is freshly swapped in). So it could be
+ * referenced concurrently by 2 types of PTEs:
+ * normal PTEs and swap PTEs. We try to handle them consistently by calling
+ * try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs,
+ * and then
+ *      - clear dirty bit to prevent IO
+ *      - remove from LRU
+ *      - but keep in the swap cache, so that when we return to it on
+ *        a later page fault, we know the application is accessing
+ *        corrupted data and shall be killed (we installed simple
+ *        interception code in do_swap_page to catch it).
+ *
+ * Clean swap cache pages can be directly isolated. A later page fault will
+ * bring in the known good data from disk.
+ */
+static int me_swapcache_dirty(struct page *p, unsigned long pfn)
+{
+        int ret = FAILED;
+
+        ClearPageDirty(p);
+        /* Trigger EIO in shmem: */
+        ClearPageUptodate(p);
+
+        if (!isolate_lru_page(p)) {
+                page_cache_release(p);
+                ret = DELAYED;
+        }
+
+        return ret;
+}
+
+static int me_swapcache_clean(struct page *p, unsigned long pfn)
+{
+        int ret = FAILED;
+
+        if (!isolate_lru_page(p)) {
+                page_cache_release(p);
+                ret = RECOVERED;
+        }
+        delete_from_swap_cache(p);
+        return ret;
+}
+
+/*
+ * Huge pages. Needs work.
+ * Issues:
+ * No rmap support so we cannot find the original mapper. In theory could walk
+ * all MMs and look for the mappings, but that would be non atomic and racy.
+ * Need rmap for hugepages for this. Alternatively we could employ a heuristic,
+ * like just walking the current process and hoping it has it mapped (that
+ * should be usually true for the common "shared database cache" case)
+ * Should handle free huge pages and dequeue them too, but this needs to
+ * handle huge page accounting correctly.
+ */
+static int me_huge_page(struct page *p, unsigned long pfn)
+{
+        return FAILED;
+}
+
+/*
+ * Various page states we can handle.
+ *
+ * A page state is defined by its current page->flags bits.
+ * The table matches them in order and calls the right handler.
+ *
+ * This is quite tricky because we can access page at any time
+ * in its live cycle, so all accesses have to be extremly careful.
+ *
+ * This is not complete. More states could be added.
+ * For any missing state don't attempt recovery.
+ */
+
+#define dirty           (1UL << PG_dirty)
+#define sc              (1UL << PG_swapcache)
+#define unevict         (1UL << PG_unevictable)
+#define mlock           (1UL << PG_mlocked)
+#define writeback       (1UL << PG_writeback)
+#define lru             (1UL << PG_lru)
+#define swapbacked      (1UL << PG_swapbacked)
+#define head            (1UL << PG_head)
+#define tail            (1UL << PG_tail)
+#define compound        (1UL << PG_compound)
+#define slab            (1UL << PG_slab)
+#define buddy           (1UL << PG_buddy)
+#define reserved        (1UL << PG_reserved)
+
+static struct page_state {
+        unsigned long mask;
+        unsigned long res;
+        char *msg;
+        int (*action)(struct page *p, unsigned long pfn);
+} error_states[] = {
+        { reserved,     reserved,       "reserved kernel",      me_ignore },
+        { buddy,        buddy,          "free kernel",  me_free },
+
+        /*
+         * Could in theory check if slab page is free or if we can drop
+         * currently unused objects without touching them. But just
+         * treat it as standard kernel for now.
+         */
+        { slab,         slab,           "kernel slab",  me_kernel },
+
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+        { head,         head,           "huge",         me_huge_page },
+        { tail,         tail,           "huge",         me_huge_page },
+#else
+        { compound,     compound,       "huge",         me_huge_page },
+#endif
+
+        { sc|dirty,     sc|dirty,       "swapcache",    me_swapcache_dirty },
+        { sc|dirty,     sc,             "swapcache",    me_swapcache_clean },
+
+        { unevict|dirty, unevict|dirty, "unevictable LRU", me_pagecache_dirty},
+        { unevict,      unevict,        "unevictable LRU", me_pagecache_clean},
+
+#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
+        { mlock|dirty,  mlock|dirty,    "mlocked LRU",  me_pagecache_dirty },
+        { mlock,        mlock,          "mlocked LRU",  me_pagecache_clean },
+#endif
+
+        { lru|dirty,    lru|dirty,      "LRU",          me_pagecache_dirty },
+        { lru|dirty,    lru,            "clean LRU",    me_pagecache_clean },
+        { swapbacked,   swapbacked,     "anonymous",    me_pagecache_clean },
+
+        /*
+         * Catchall entry: must be at end.
+         */
+        { 0,            0,              "unknown page state",   me_unknown },
+};
+
+#undef lru
+
+static void action_result(unsigned long pfn, char *msg, int result)
+{
+        struct page *page = NULL;
+        if (pfn_valid(pfn))
+                page = pfn_to_page(pfn);
+
+        printk(KERN_ERR "MCE %#lx: %s%s page recovery: %s\n",
+                pfn,
+                page && PageDirty(page) ? "dirty " : "",
+                msg, action_name[result]);
+}
+
+static int page_action(struct page_state *ps, struct page *p,
+                        unsigned long pfn, int ref)
+{
+        int result;
+
+        result = ps->action(p, pfn);
+        action_result(pfn, ps->msg, result);
+        if (page_count(p) != 1 + ref)
+                printk(KERN_ERR
+                       "MCE %#lx: %s page still referenced by %d users\n",
+                       pfn, ps->msg, page_count(p) - 1);
+
+        /* Could do more checks here if page looks ok */
+        /*
+         * Could adjust zone counters here to correct for the missing page.
+         */
+
+        return result == RECOVERED ? 0 : -EBUSY;
+}
+
+#define N_UNMAP_TRIES 5
+
+/*
+ * Do all that is necessary to remove user space mappings. Unmap
+ * the pages and send SIGBUS to the processes if the data was dirty.
+ */
+static void hwpoison_user_mappings(struct page *p, unsigned long pfn,
+                                  int trapno)
+{
+        enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
+        struct address_space *mapping;
+        LIST_HEAD(tokill);
+        int ret;
+        int i;
+        int kill = 1;
+
+        if (PageReserved(p) || PageCompound(p) || PageSlab(p))
+                return;
+
+        if (!PageLRU(p))
+                lru_add_drain_all();
+
+        /*
+         * This check implies we don't kill processes if their pages
+         * are in the swap cache early. Those are always late kills.
+         */
+        if (!page_mapped(p))
+                return;
+
+        if (PageSwapCache(p)) {
+                printk(KERN_ERR
+                       "MCE %#lx: keeping poisoned page in swap cache\n", pfn);
+                ttu |= TTU_IGNORE_HWPOISON;
+        }
+
+        /*
+         * Propagate the dirty bit from PTEs to struct page first, because we
+         * need this to decide if we should kill or just drop the page.
+         */
+        mapping = page_mapping(p);
+        if (!PageDirty(p) && mapping && mapping_cap_writeback_dirty(mapping)) {
+                if (page_mkclean(p)) {
+                        SetPageDirty(p);
+                } else {
+                        kill = 0;
+                        ttu |= TTU_IGNORE_HWPOISON;
+                        printk(KERN_INFO
+        "MCE %#lx: corrupted page was clean: dropped without side effects\n",
+                                pfn);
+                }
+        }
+
+        /*
+         * First collect all the processes that have the page
+         * mapped in dirty form.  This has to be done before try_to_unmap,
+         * because ttu takes the rmap data structures down.
+         *
+         * Error handling: We ignore errors here because
+         * there's nothing that can be done.
+         */
+        if (kill)
+                collect_procs(p, &tokill);
+
+        /*
+         * try_to_unmap can fail temporarily due to races.
+         * Try a few times (RED-PEN better strategy?)
+         */
+        for (i = 0; i < N_UNMAP_TRIES; i++) {
+                ret = try_to_unmap(p, ttu);
+                if (ret == SWAP_SUCCESS)
+                        break;
+                pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn,  ret);
+        }
+
+        if (ret != SWAP_SUCCESS)
+                printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
+                                pfn, page_mapcount(p));
+
+        /*
+         * Now that the dirty bit has been propagated to the
+         * struct page and all unmaps done we can decide if
+         * killing is needed or not.  Only kill when the page
+         * was dirty, otherwise the tokill list is merely
+         * freed.  When there was a problem unmapping earlier
+         * use a more force-full uncatchable kill to prevent
+         * any accesses to the poisoned memory.
+         */
+        kill_procs_ao(&tokill, !!PageDirty(p), trapno,
+                      ret != SWAP_SUCCESS, pfn);
+}
+
+int __memory_failure(unsigned long pfn, int trapno, int ref)
+{
+        struct page_state *ps;
+        struct page *p;
+        int res;
+
+        if (!sysctl_memory_failure_recovery)
+                panic("Memory failure from trap %d on page %lx", trapno, pfn);
+
+        if (!pfn_valid(pfn)) {
+                action_result(pfn, "memory outside kernel control", IGNORED);
+                return -EIO;
+        }
+
+        p = pfn_to_page(pfn);
+        if (TestSetPageHWPoison(p)) {
+                action_result(pfn, "already hardware poisoned", IGNORED);
+                return 0;
+        }
+
+        atomic_long_add(1, &mce_bad_pages);
+
+        /*
+         * We need/can do nothing about count=0 pages.
+         * 1) it's a free page, and therefore in safe hand:
+         *    prep_new_page() will be the gate keeper.
+         * 2) it's part of a non-compound high order page.
+         *    Implies some kernel user: cannot stop them from
+         *    R/W the page; let's pray that the page has been
+         *    used and will be freed some time later.
+         * In fact it's dangerous to directly bump up page count from 0,
+         * that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
+         */
+        if (!get_page_unless_zero(compound_head(p))) {
+                action_result(pfn, "free or high order kernel", IGNORED);
+                return PageBuddy(compound_head(p)) ? 0 : -EBUSY;
+        }
+
+        /*
+         * Lock the page and wait for writeback to finish.
+         * It's very difficult to mess with pages currently under IO
+         * and in many cases impossible, so we just avoid it here.
+         */
+        lock_page_nosync(p);
+        wait_on_page_writeback(p);
+
+        /*
+         * Now take care of user space mappings.
+         */
+        hwpoison_user_mappings(p, pfn, trapno);
+
+        /*
+         * Torn down by someone else?
+         */
+        if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
+                action_result(pfn, "already truncated LRU", IGNORED);
+                res = 0;
+                goto out;
+        }
+
+        res = -EBUSY;
+        for (ps = error_states;; ps++) {
+                if ((p->flags & ps->mask) == ps->res) {
+                        res = page_action(ps, p, pfn, ref);
+                        break;
+                }
+        }
+out:
+        unlock_page(p);
+        return res;
+}
+EXPORT_SYMBOL_GPL(__memory_failure);
+
+/**
+ * memory_failure - Handle memory failure of a page.
+ * @pfn: Page Number of the corrupted page
+ * @trapno: Trap number reported in the signal to user space.
+ *
+ * This function is called by the low level machine check code
+ * of an architecture when it detects hardware memory corruption
+ * of a page. It tries its best to recover, which includes
+ * dropping pages, killing processes etc.
+ *
+ * The function is primarily of use for corruptions that
+ * happen outside the current execution context (e.g. when
+ * detected by a background scrubber)
+ *
+ * Must run in process context (e.g. a work queue) with interrupts
+ * enabled and no spinlocks hold.
+ */
+void memory_failure(unsigned long pfn, int trapno)
+{
+        __memory_failure(pfn, trapno, 0);
+}
diff --git a/mm/memory.c b/mm/memory.c
index aede2ce3aba4..7e91b5f9f690 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -45,6 +45,7 @@
 #include <linux/swap.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
+#include <linux/ksm.h>
 #include <linux/rmap.h>
 #include <linux/module.h>
 #include <linux/delayacct.h>
@@ -56,6 +57,7 @@
 #include <linux/swapops.h>
 #include <linux/elf.h>
 
+#include <asm/io.h>
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
 #include <asm/tlb.h>
@@ -106,6 +108,18 @@ static int __init disable_randmaps(char *s)
 }
 __setup("norandmaps", disable_randmaps);
 
+unsigned long zero_pfn __read_mostly;
+unsigned long highest_memmap_pfn __read_mostly;
+
+/*
+ * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init()
+ */
+static int __init init_zero_pfn(void)
+{
+        zero_pfn = page_to_pfn(ZERO_PAGE(0));
+        return 0;
+}
+core_initcall(init_zero_pfn);
 
 /*
  * If a p?d_bad entry is found while walking page tables, report
@@ -283,7 +297,8 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
                 unsigned long addr = vma->vm_start;
 
                 /*
-                 * Hide vma from rmap and vmtruncate before freeing pgtables
+                 * Hide vma from rmap and truncate_pagecache before freeing
+                 * pgtables
                  */
                 anon_vma_unlink(vma);
                 unlink_file_vma(vma);
@@ -442,6 +457,20 @@ static inline int is_cow_mapping(unsigned int flags)
         return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
 }
 
+#ifndef is_zero_pfn
+static inline int is_zero_pfn(unsigned long pfn)
+{
+        return pfn == zero_pfn;
+}
+#endif
+
+#ifndef my_zero_pfn
+static inline unsigned long my_zero_pfn(unsigned long addr)
+{
+        return zero_pfn;
+}
+#endif
+
 /*
  * vm_normal_page -- This function gets the "struct page" associated with a pte.
  *
@@ -497,7 +526,9 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
         if (HAVE_PTE_SPECIAL) {
                 if (likely(!pte_special(pte)))
                         goto check_pfn;
-                if (!(vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)))
+                if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
+                        return NULL;
+                if (!is_zero_pfn(pfn))
                         print_bad_pte(vma, addr, pte, NULL);
                 return NULL;
         }
@@ -519,6 +550,8 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
                 }
         }
 
+        if (is_zero_pfn(pfn))
+                return NULL;
 check_pfn:
         if (unlikely(pfn > highest_memmap_pfn)) {
                 print_bad_pte(vma, addr, pte, NULL);
@@ -596,8 +629,8 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
         page = vm_normal_page(vma, addr, pte);
         if (page) {
                 get_page(page);
-                page_dup_rmap(page, vma, addr);
-                rss[!!PageAnon(page)]++;
+                page_dup_rmap(page);
+                rss[PageAnon(page)]++;
         }
 
 out_set_pte:
@@ -1142,9 +1175,14 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
                 goto no_page;
         if ((flags & FOLL_WRITE) && !pte_write(pte))
                 goto unlock;
+
         page = vm_normal_page(vma, address, pte);
-        if (unlikely(!page))
-                goto bad_page;
+        if (unlikely(!page)) {
+                if ((flags & FOLL_DUMP) ||
+                    !is_zero_pfn(pte_pfn(pte)))
+                        goto bad_page;
+                page = pte_page(pte);
+        }
 
         if (flags & FOLL_GET)
                 get_page(page);
@@ -1172,65 +1210,46 @@ no_page:
         pte_unmap_unlock(ptep, ptl);
         if (!pte_none(pte))
                 return page;
-        /* Fall through to ZERO_PAGE handling */
+
 no_page_table:
         /*
          * When core dumping an enormous anonymous area that nobody
-         * has touched so far, we don't want to allocate page tables.
+         * has touched so far, we don't want to allocate unnecessary pages or
+         * page tables.  Return error instead of NULL to skip handle_mm_fault,
+         * then get_dump_page() will return NULL to leave a hole in the dump.
+         * But we can only make this optimization where a hole would surely
+         * be zero-filled if handle_mm_fault() actually did handle it.
          */
-        if (flags & FOLL_ANON) {
-                page = ZERO_PAGE(0);
-                if (flags & FOLL_GET)
-                        get_page(page);
-                BUG_ON(flags & FOLL_WRITE);
-        }
+        if ((flags & FOLL_DUMP) &&
+            (!vma->vm_ops || !vma->vm_ops->fault))
+                return ERR_PTR(-EFAULT);
         return page;
 }
 
-/* Can we do the FOLL_ANON optimization? */
-static inline int use_zero_page(struct vm_area_struct *vma)
-{
-        /*
-         * We don't want to optimize FOLL_ANON for make_pages_present()
-         * when it tries to page in a VM_LOCKED region. As to VM_SHARED,
-         * we want to get the page from the page tables to make sure
-         * that we serialize and update with any other user of that
-         * mapping.
-         */
-        if (vma->vm_flags & (VM_LOCKED | VM_SHARED))
-                return 0;
-        /*
-         * And if we have a fault routine, it's not an anonymous region.
-         */
-        return !vma->vm_ops || !vma->vm_ops->fault;
-}
-
-
-
 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-                     unsigned long start, int nr_pages, int flags,
+                     unsigned long start, int nr_pages, unsigned int gup_flags,
                      struct page **pages, struct vm_area_struct **vmas)
 {
         int i;
-        unsigned int vm_flags = 0;
-        int write = !!(flags & GUP_FLAGS_WRITE);
-        int force = !!(flags & GUP_FLAGS_FORCE);
-        int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
-        int ignore_sigkill = !!(flags & GUP_FLAGS_IGNORE_SIGKILL);
+        unsigned long vm_flags;
 
         if (nr_pages <= 0)
                 return 0;
+
+        VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET));
+
         /* 
          * Require read or write permissions.
-         * If 'force' is set, we only require the "MAY" flags.
+         * If FOLL_FORCE is set, we only require the "MAY" flags.
          */
-        vm_flags  = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
-        vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
+        vm_flags  = (gup_flags & FOLL_WRITE) ?
+                        (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
+        vm_flags &= (gup_flags & FOLL_FORCE) ?
+                        (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
         i = 0;
 
         do {
                 struct vm_area_struct *vma;
-                unsigned int foll_flags;
 
                 vma = find_extend_vma(mm, start);
                 if (!vma && in_gate_area(tsk, start)) {
@@ -1242,7 +1261,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         pte_t *pte;
 
                         /* user gate pages are read-only */
-                        if (!ignore && write)
+                        if (gup_flags & FOLL_WRITE)
                                 return i ? : -EFAULT;
                         if (pg > TASK_SIZE)
                                 pgd = pgd_offset_k(pg);
@@ -1276,38 +1295,26 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 
                 if (!vma ||
                     (vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
-                    (!ignore && !(vm_flags & vma->vm_flags)))
+                    !(vm_flags & vma->vm_flags))
                         return i ? : -EFAULT;
 
                 if (is_vm_hugetlb_page(vma)) {
                         i = follow_hugetlb_page(mm, vma, pages, vmas,
-                                                &start, &nr_pages, i, write);
+                                        &start, &nr_pages, i, gup_flags);
                         continue;
                 }
 
-                foll_flags = FOLL_TOUCH;
-                if (pages)
-                        foll_flags |= FOLL_GET;
-                if (!write && use_zero_page(vma))
-                        foll_flags |= FOLL_ANON;
-
                 do {
                         struct page *page;
+                        unsigned int foll_flags = gup_flags;
 
                         /*
                          * If we have a pending SIGKILL, don't keep faulting
-                         * pages and potentially allocating memory, unless
-                         * current is handling munlock--e.g., on exit. In
-                         * that case, we are not allocating memory.  Rather,
-                         * we're only unlocking already resident/mapped pages.
+                         * pages and potentially allocating memory.
                          */
-                        if (unlikely(!ignore_sigkill &&
-                                        fatal_signal_pending(current)))
+                        if (unlikely(fatal_signal_pending(current)))
                                 return i ? i : -ERESTARTSYS;
 
-                        if (write)
-                                foll_flags |= FOLL_WRITE;
-
                         cond_resched();
                         while (!(page = follow_page(vma, start, foll_flags))) {
                                 int ret;
@@ -1319,7 +1326,8 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                                 if (ret & VM_FAULT_ERROR) {
                                         if (ret & VM_FAULT_OOM)
                                                 return i ? i : -ENOMEM;
-                                        else if (ret & VM_FAULT_SIGBUS)
+                                        if (ret &
+                                            (VM_FAULT_HWPOISON|VM_FAULT_SIGBUS))
                                                 return i ? i : -EFAULT;
                                         BUG();
                                 }
@@ -1418,18 +1426,47 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                 unsigned long start, int nr_pages, int write, int force,
                 struct page **pages, struct vm_area_struct **vmas)
 {
-        int flags = 0;
+        int flags = FOLL_TOUCH;
 
+        if (pages)
+                flags |= FOLL_GET;
         if (write)
-                flags |= GUP_FLAGS_WRITE;
+                flags |= FOLL_WRITE;
         if (force)
-                flags |= GUP_FLAGS_FORCE;
+                flags |= FOLL_FORCE;
 
         return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
 }
-
 EXPORT_SYMBOL(get_user_pages);
 
+/**
+ * get_dump_page() - pin user page in memory while writing it to core dump
+ * @addr: user address
+ *
+ * Returns struct page pointer of user page pinned for dump,
+ * to be freed afterwards by page_cache_release() or put_page().
+ *
+ * Returns NULL on any kind of failure - a hole must then be inserted into
+ * the corefile, to preserve alignment with its headers; and also returns
+ * NULL wherever the ZERO_PAGE, or an anonymous pte_none, has been found -
+ * allowing a hole to be left in the corefile to save diskspace.
+ *
+ * Called without mmap_sem, but after all other threads have been killed.
+ */
+#ifdef CONFIG_ELF_CORE
+struct page *get_dump_page(unsigned long addr)
+{
+        struct vm_area_struct *vma;
+        struct page *page;
+
+        if (__get_user_pages(current, current->mm, addr, 1,
+                        FOLL_FORCE | FOLL_DUMP | FOLL_GET, &page, &vma) < 1)
+                return NULL;
+        flush_cache_page(vma, addr, page_to_pfn(page));
+        return page;
+}
+#endif /* CONFIG_ELF_CORE */
+
 pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
                         spinlock_t **ptl)
 {
@@ -1607,7 +1644,8 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
          * If we don't have pte special, then we have to use the pfn_valid()
          * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
          * refcount the page if pfn_valid is true (hence insert_page rather
-         * than insert_pfn).
+         * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
+         * without pte special, it would there be refcounted as a normal page.
          */
         if (!HAVE_PTE_SPECIAL && pfn_valid(pfn)) {
                 struct page *page;
@@ -1973,7 +2011,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
          * Take out anonymous pages first, anonymous shared vmas are
          * not dirty accountable.
          */
-        if (PageAnon(old_page)) {
+        if (PageAnon(old_page) && !PageKsm(old_page)) {
                 if (!trylock_page(old_page)) {
                         page_cache_get(old_page);
                         pte_unmap_unlock(page_table, ptl);
@@ -2074,10 +2112,19 @@ gotten:
 
         if (unlikely(anon_vma_prepare(vma)))
                 goto oom;
-        VM_BUG_ON(old_page == ZERO_PAGE(0));
-        new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
-        if (!new_page)
-                goto oom;
+
+        if (is_zero_pfn(pte_pfn(orig_pte))) {
+                new_page = alloc_zeroed_user_highpage_movable(vma, address);
+                if (!new_page)
+                        goto oom;
+        } else {
+                new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+                if (!new_page)
+                        goto oom;
+                cow_user_page(new_page, old_page, address, vma);
+        }
+        __SetPageUptodate(new_page);
+
         /*
          * Don't let another task, with possibly unlocked vma,
          * keep the mlocked page.
@@ -2087,8 +2134,6 @@ gotten:
                 clear_page_mlock(old_page);
                 unlock_page(old_page);
         }
-        cow_user_page(new_page, old_page, address, vma);
-        __SetPageUptodate(new_page);
 
         if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))
                 goto oom_free_new;
@@ -2114,9 +2159,14 @@ gotten:
                  * seen in the presence of one thread doing SMC and another
                  * thread doing COW.
                  */
-                ptep_clear_flush_notify(vma, address, page_table);
+                ptep_clear_flush(vma, address, page_table);
                 page_add_new_anon_rmap(new_page, vma, address);
-                set_pte_at(mm, address, page_table, entry);
+                /*
+                 * We call the notify macro here because, when using secondary
+                 * mmu page tables (such as kvm shadow page tables), we want the
+                 * new page to be mapped directly into the secondary page table.
+                 */
+                set_pte_at_notify(mm, address, page_table, entry);
                 update_mmu_cache(vma, address, entry);
                 if (old_page) {
                         /*
@@ -2359,7 +2409,7 @@ restart:
  * @mapping: the address space containing mmaps to be unmapped.
  * @holebegin: byte in first page to unmap, relative to the start of
  * the underlying file.  This will be rounded down to a PAGE_SIZE
- * boundary.  Note that this is different from vmtruncate(), which
+ * boundary.  Note that this is different from truncate_pagecache(), which
  * must keep the partial page.  In contrast, we must get rid of
  * partial pages.
  * @holelen: size of prospective hole in bytes.  This will be rounded
@@ -2410,63 +2460,6 @@ void unmap_mapping_range(struct address_space *mapping,
 }
 EXPORT_SYMBOL(unmap_mapping_range);
 
-/**
- * vmtruncate - unmap mappings "freed" by truncate() syscall
- * @inode: inode of the file used
- * @offset: file offset to start truncating
- *
- * NOTE! We have to be ready to update the memory sharing
- * between the file and the memory map for a potential last
- * incomplete page.  Ugly, but necessary.
- */
-int vmtruncate(struct inode * inode, loff_t offset)
-{
-        if (inode->i_size < offset) {
-                unsigned long limit;
-
-                limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
-                if (limit != RLIM_INFINITY && offset > limit)
-                        goto out_sig;
-                if (offset > inode->i_sb->s_maxbytes)
-                        goto out_big;
-                i_size_write(inode, offset);
-        } else {
-                struct address_space *mapping = inode->i_mapping;
-
-                /*
-                 * truncation of in-use swapfiles is disallowed - it would
-                 * cause subsequent swapout to scribble on the now-freed
-                 * blocks.
-                 */
-                if (IS_SWAPFILE(inode))
-                        return -ETXTBSY;
-                i_size_write(inode, offset);
-
-                /*
-                 * unmap_mapping_range is called twice, first simply for
-                 * efficiency so that truncate_inode_pages does fewer
-                 * single-page unmaps.  However after this first call, and
-                 * before truncate_inode_pages finishes, it is possible for
-                 * private pages to be COWed, which remain after
-                 * truncate_inode_pages finishes, hence the second
-                 * unmap_mapping_range call must be made for correctness.
-                 */
-                unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
-                truncate_inode_pages(mapping, offset);
-                unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
-        }
-
-        if (inode->i_op->truncate)
-                inode->i_op->truncate(inode);
-        return 0;
-
-out_sig:
-        send_sig(SIGXFSZ, current, 0);
-out_big:
-        return -EFBIG;
-}
-EXPORT_SYMBOL(vmtruncate);
-
 int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
 {
         struct address_space *mapping = inode->i_mapping;
@@ -2511,8 +2504,15 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 goto out;
 
         entry = pte_to_swp_entry(orig_pte);
-        if (is_migration_entry(entry)) {
-                migration_entry_wait(mm, pmd, address);
+        if (unlikely(non_swap_entry(entry))) {
+                if (is_migration_entry(entry)) {
+                        migration_entry_wait(mm, pmd, address);
+                } else if (is_hwpoison_entry(entry)) {
+                        ret = VM_FAULT_HWPOISON;
+                } else {
+                        print_bad_pte(vma, address, orig_pte, NULL);
+                        ret = VM_FAULT_OOM;
+                }
                 goto out;
         }
         delayacct_set_flag(DELAYACCT_PF_SWAPIN);
@@ -2536,6 +2536,10 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 /* Had to read the page from swap area: Major fault */
                 ret = VM_FAULT_MAJOR;
                 count_vm_event(PGMAJFAULT);
+        } else if (PageHWPoison(page)) {
+                ret = VM_FAULT_HWPOISON;
+                delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+                goto out;
         }
 
         lock_page(page);
@@ -2624,6 +2628,16 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
         spinlock_t *ptl;
         pte_t entry;
 
+        if (!(flags & FAULT_FLAG_WRITE)) {
+                entry = pte_mkspecial(pfn_pte(my_zero_pfn(address),
+                                                vma->vm_page_prot));
+                ptl = pte_lockptr(mm, pmd);
+                spin_lock(ptl);
+                if (!pte_none(*page_table))
+                        goto unlock;
+                goto setpte;
+        }
+
         /* Allocate our own private page. */
         pte_unmap(page_table);
 
@@ -2638,13 +2652,16 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 goto oom_free_page;
 
         entry = mk_pte(page, vma->vm_page_prot);
-        entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+        if (vma->vm_flags & VM_WRITE)
+                entry = pte_mkwrite(pte_mkdirty(entry));
 
         page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
         if (!pte_none(*page_table))
                 goto release;
+
         inc_mm_counter(mm, anon_rss);
         page_add_new_anon_rmap(page, vma, address);
+setpte:
         set_pte_at(mm, address, page_table, entry);
 
         /* No need to invalidate - it was non-present before */
@@ -2699,6 +2716,12 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
         if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
                 return ret;
 
+        if (unlikely(PageHWPoison(vmf.page))) {
+                if (ret & VM_FAULT_LOCKED)
+                        unlock_page(vmf.page);
+                return VM_FAULT_HWPOISON;
+        }
+
         /*
          * For consistency in subsequent calls, make the faulted page always
          * locked.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e4412a676c88..821dee596377 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -339,8 +339,11 @@ EXPORT_SYMBOL_GPL(__remove_pages);
 
 void online_page(struct page *page)
 {
+        unsigned long pfn = page_to_pfn(page);
+
         totalram_pages++;
-        num_physpages++;
+        if (pfn >= num_physpages)
+                num_physpages = pfn + 1;
 
 #ifdef CONFIG_HIGHMEM
         if (PageHighMem(page))
@@ -410,7 +413,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
         if (!populated_zone(zone))
                 need_zonelists_rebuild = 1;
 
-        ret = walk_memory_resource(pfn, nr_pages, &onlined_pages,
+        ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
                 online_pages_range);
         if (ret) {
                 printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
@@ -422,6 +425,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
         zone->present_pages += onlined_pages;
         zone->zone_pgdat->node_present_pages += onlined_pages;
 
+        zone_pcp_update(zone);
         setup_per_zone_wmarks();
         calculate_zone_inactive_ratio(zone);
         if (onlined_pages) {
@@ -701,7 +705,7 @@ offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
 static void
 offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
 {
-        walk_memory_resource(start_pfn, end_pfn - start_pfn, NULL,
+        walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
                                 offline_isolated_pages_cb);
 }
 
@@ -727,7 +731,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
         long offlined = 0;
         int ret;
 
-        ret = walk_memory_resource(start_pfn, end_pfn - start_pfn, &offlined,
+        ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
                         check_pages_isolated_cb);
         if (ret < 0)
                 offlined = (long)ret;
@@ -831,7 +835,6 @@ repeat:
         zone->present_pages -= offlined_pages;
         zone->zone_pgdat->node_present_pages -= offlined_pages;
         totalram_pages -= offlined_pages;
-        num_physpages -= offlined_pages;
 
         setup_per_zone_wmarks();
         calculate_zone_inactive_ratio(zone);
diff --git a/mm/mempool.c b/mm/mempool.c
index 32e75d400503..1a3bc3d4d554 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -308,13 +308,6 @@ void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
 }
 EXPORT_SYMBOL(mempool_kmalloc);
 
-void *mempool_kzalloc(gfp_t gfp_mask, void *pool_data)
-{
-        size_t size = (size_t)pool_data;
-        return kzalloc(size, gfp_mask);
-}
-EXPORT_SYMBOL(mempool_kzalloc);
-
 void mempool_kfree(void *element, void *pool_data)
 {
         kfree(element);
diff --git a/mm/migrate.c b/mm/migrate.c
index 939888f9ddab..1a4bf4813780 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -67,6 +67,8 @@ int putback_lru_pages(struct list_head *l)
 
         list_for_each_entry_safe(page, page2, l, lru) {
                 list_del(&page->lru);
+                dec_zone_page_state(page, NR_ISOLATED_ANON +
+                                page_is_file_cache(page));
                 putback_lru_page(page);
                 count++;
         }
@@ -147,7 +149,7 @@ out:
 static void remove_file_migration_ptes(struct page *old, struct page *new)
 {
         struct vm_area_struct *vma;
-        struct address_space *mapping = page_mapping(new);
+        struct address_space *mapping = new->mapping;
         struct prio_tree_iter iter;
         pgoff_t pgoff = new->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
 
@@ -270,7 +272,7 @@ static int migrate_page_move_mapping(struct address_space *mapping,
         pslot = radix_tree_lookup_slot(&mapping->page_tree,
                                         page_index(page));
 
-        expected_count = 2 + !!page_has_private(page);
+        expected_count = 2 + page_has_private(page);
         if (page_count(page) != expected_count ||
                         (struct page *)radix_tree_deref_slot(pslot) != page) {
                 spin_unlock_irq(&mapping->tree_lock);
@@ -312,7 +314,10 @@ static int migrate_page_move_mapping(struct address_space *mapping,
          */
         __dec_zone_page_state(page, NR_FILE_PAGES);
         __inc_zone_page_state(newpage, NR_FILE_PAGES);
-
+        if (PageSwapBacked(page)) {
+                __dec_zone_page_state(page, NR_SHMEM);
+                __inc_zone_page_state(newpage, NR_SHMEM);
+        }
         spin_unlock_irq(&mapping->tree_lock);
 
         return 0;
@@ -664,13 +669,15 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
                          *    needs to be effective.
                          */
                         try_to_free_buffers(page);
+                        goto rcu_unlock;
                 }
-                goto rcu_unlock;
+                goto skip_unmap;
         }
 
         /* Establish migration ptes or remove ptes */
-        try_to_unmap(page, 1);
+        try_to_unmap(page, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
 
+skip_unmap:
         if (!page_mapped(page))
                 rc = move_to_new_page(newpage, page);
 
@@ -693,6 +700,8 @@ unlock:
                  * restored.
                  */
                 list_del(&page->lru);
+                dec_zone_page_state(page, NR_ISOLATED_ANON +
+                                page_is_file_cache(page));
                 putback_lru_page(page);
         }
 
@@ -737,6 +746,13 @@ int migrate_pages(struct list_head *from,
         struct page *page2;
         int swapwrite = current->flags & PF_SWAPWRITE;
         int rc;
+        unsigned long flags;
+
+        local_irq_save(flags);
+        list_for_each_entry(page, from, lru)
+                __inc_zone_page_state(page, NR_ISOLATED_ANON +
+                                page_is_file_cache(page));
+        local_irq_restore(flags);
 
         if (!swapwrite)
                 current->flags |= PF_SWAPWRITE;
diff --git a/mm/mlock.c b/mm/mlock.c
index 45eb650b9654..bd6f0e466f6c 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -139,49 +139,36 @@ static void munlock_vma_page(struct page *page)
 }
 
 /**
- * __mlock_vma_pages_range() -  mlock/munlock a range of pages in the vma.
+ * __mlock_vma_pages_range() -  mlock a range of pages in the vma.
  * @vma:   target vma
  * @start: start address
  * @end:   end address
- * @mlock: 0 indicate munlock, otherwise mlock.
  *
- * If @mlock == 0, unlock an mlocked range;
- * else mlock the range of pages.  This takes care of making the pages present ,
- * too.
+ * This takes care of making the pages present too.
  *
  * return 0 on success, negative error code on error.
  *
  * vma->vm_mm->mmap_sem must be held for at least read.
  */
 static long __mlock_vma_pages_range(struct vm_area_struct *vma,
-                                   unsigned long start, unsigned long end,
-                                   int mlock)
+                                    unsigned long start, unsigned long end)
 {
         struct mm_struct *mm = vma->vm_mm;
         unsigned long addr = start;
         struct page *pages[16]; /* 16 gives a reasonable batch */
         int nr_pages = (end - start) / PAGE_SIZE;
         int ret = 0;
-        int gup_flags = 0;
+        int gup_flags;
 
         VM_BUG_ON(start & ~PAGE_MASK);
         VM_BUG_ON(end   & ~PAGE_MASK);
         VM_BUG_ON(start < vma->vm_start);
         VM_BUG_ON(end   > vma->vm_end);
-        VM_BUG_ON((!rwsem_is_locked(&mm->mmap_sem)) &&
-                  (atomic_read(&mm->mm_users) != 0));
-
-        /*
-         * mlock:   don't page populate if vma has PROT_NONE permission.
-         * munlock: always do munlock although the vma has PROT_NONE
-         *          permission, or SIGKILL is pending.
-         */
-        if (!mlock)
-                gup_flags |= GUP_FLAGS_IGNORE_VMA_PERMISSIONS |
-                             GUP_FLAGS_IGNORE_SIGKILL;
+        VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
 
+        gup_flags = FOLL_TOUCH | FOLL_GET;
         if (vma->vm_flags & VM_WRITE)
-                gup_flags |= GUP_FLAGS_WRITE;
+                gup_flags |= FOLL_WRITE;
 
         while (nr_pages > 0) {
                 int i;
@@ -201,51 +188,45 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
                  * This can happen for, e.g., VM_NONLINEAR regions before
                  * a page has been allocated and mapped at a given offset,
                  * or for addresses that map beyond end of a file.
-                 * We'll mlock the the pages if/when they get faulted in.
+                 * We'll mlock the pages if/when they get faulted in.
                  */
                 if (ret < 0)
                         break;
-                if (ret == 0) {
-                        /*
-                         * We know the vma is there, so the only time
-                         * we cannot get a single page should be an
-                         * error (ret < 0) case.
-                         */
-                        WARN_ON(1);
-                        break;
-                }
 
                 lru_add_drain();        /* push cached pages to LRU */
 
                 for (i = 0; i < ret; i++) {
                         struct page *page = pages[i];
 
-                        lock_page(page);
-                        /*
-                         * Because we lock page here and migration is blocked
-                         * by the elevated reference, we need only check for
-                         * page truncation (file-cache only).
-                         */
                         if (page->mapping) {
-                                if (mlock)
+                                /*
+                                 * That preliminary check is mainly to avoid
+                                 * the pointless overhead of lock_page on the
+                                 * ZERO_PAGE: which might bounce very badly if
+                                 * there is contention.  However, we're still
+                                 * dirtying its cacheline with get/put_page:
+                                 * we'll add another __get_user_pages flag to
+                                 * avoid it if that case turns out to matter.
+                                 */
+                                lock_page(page);
+                                /*
+                                 * Because we lock page here and migration is
+                                 * blocked by the elevated reference, we need
+                                 * only check for file-cache page truncation.
+                                 */
+                                if (page->mapping)
                                         mlock_vma_page(page);
-                                else
-                                        munlock_vma_page(page);
+                                unlock_page(page);
                         }
-                        unlock_page(page);
-                        put_page(page);         /* ref from get_user_pages() */
-
-                        /*
-                         * here we assume that get_user_pages() has given us
-                         * a list of virtually contiguous pages.
-                         */
-                        addr += PAGE_SIZE;      /* for next get_user_pages() */
-                        nr_pages--;
+                        put_page(page); /* ref from get_user_pages() */
                 }
+
+                addr += ret * PAGE_SIZE;
+                nr_pages -= ret;
                 ret = 0;
         }
 
-        return ret;     /* count entire vma as locked_vm */
+        return ret;     /* 0 or negative error code */
 }
 
 /*
@@ -289,7 +270,7 @@ long mlock_vma_pages_range(struct vm_area_struct *vma,
                         is_vm_hugetlb_page(vma) ||
                         vma == get_gate_vma(current))) {
 
-                __mlock_vma_pages_range(vma, start, end, 1);
+                __mlock_vma_pages_range(vma, start, end);
 
                 /* Hide errors from mmap() and other callers */
                 return 0;
@@ -310,7 +291,6 @@ no_mlock:
         return nr_pages;                /* error or pages NOT mlocked */
 }
 
-
 /*
  * munlock_vma_pages_range() - munlock all pages in the vma range.'
  * @vma - vma containing range to be munlock()ed.
@@ -330,10 +310,38 @@ no_mlock:
  * free them.  This will result in freeing mlocked pages.
  */
 void munlock_vma_pages_range(struct vm_area_struct *vma,
-                           unsigned long start, unsigned long end)
+                             unsigned long start, unsigned long end)
 {
+        unsigned long addr;
+
+        lru_add_drain();
         vma->vm_flags &= ~VM_LOCKED;
-        __mlock_vma_pages_range(vma, start, end, 0);
+
+        for (addr = start; addr < end; addr += PAGE_SIZE) {
+                struct page *page;
+                /*
+                 * Although FOLL_DUMP is intended for get_dump_page(),
+                 * it just so happens that its special treatment of the
+                 * ZERO_PAGE (returning an error instead of doing get_page)
+                 * suits munlock very well (and if somehow an abnormal page
+                 * has sneaked into the range, we won't oops here: great).
+                 */
+                page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP);
+                if (page && !IS_ERR(page)) {
+                        lock_page(page);
+                        /*
+                         * Like in __mlock_vma_pages_range(),
+                         * because we lock page here and migration is
+                         * blocked by the elevated reference, we need
+                         * only check for file-cache page truncation.
+                         */
+                        if (page->mapping)
+                                munlock_vma_page(page);
+                        unlock_page(page);
+                        put_page(page);
+                }
+                cond_resched();
+        }
 }
 
 /*
@@ -400,18 +408,14 @@ success:
          * It's okay if try_to_unmap_one unmaps a page just after we
          * set VM_LOCKED, __mlock_vma_pages_range will bring it back.
          */
-        vma->vm_flags = newflags;
 
         if (lock) {
-                ret = __mlock_vma_pages_range(vma, start, end, 1);
-
-                if (ret > 0) {
-                        mm->locked_vm -= ret;
-                        ret = 0;
-                } else
-                        ret = __mlock_posix_error_return(ret); /* translate if needed */
+                vma->vm_flags = newflags;
+                ret = __mlock_vma_pages_range(vma, start, end);
+                if (ret < 0)
+                        ret = __mlock_posix_error_return(ret);
         } else {
-                __mlock_vma_pages_range(vma, start, end, 0);
+                munlock_vma_pages_range(vma, start, end);
         }
 
 out:
diff --git a/mm/mmap.c b/mm/mmap.c
index 8101de490c73..73f5e4b64010 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -28,7 +28,7 @@
 #include <linux/mempolicy.h>
 #include <linux/rmap.h>
 #include <linux/mmu_notifier.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
@@ -570,9 +570,9 @@ again:			remove_next = 1 + (end > next->vm_end);
 
         /*
          * When changing only vma->vm_end, we don't really need
-         * anon_vma lock: but is that case worth optimizing out?
+         * anon_vma lock.
          */
-        if (vma->anon_vma)
+        if (vma->anon_vma && (insert || importer || start != vma->vm_start))
                 anon_vma = vma->anon_vma;
         if (anon_vma) {
                 spin_lock(&anon_vma->lock);
@@ -656,9 +656,6 @@ again:			remove_next = 1 + (end > next->vm_end);
         validate_mm(mm);
 }
 
-/* Flags that can be inherited from an existing mapping when merging */
-#define VM_MERGEABLE_FLAGS (VM_CAN_NONLINEAR)
-
 /*
  * If the vma has a ->close operation then the driver probably needs to release
  * per-vma resources, so we don't attempt to merge those.
@@ -666,7 +663,8 @@ again:			remove_next = 1 + (end > next->vm_end);
 static inline int is_mergeable_vma(struct vm_area_struct *vma,
                         struct file *file, unsigned long vm_flags)
 {
-        if ((vma->vm_flags ^ vm_flags) & ~VM_MERGEABLE_FLAGS)
+        /* VM_CAN_NONLINEAR may get set later by f_op->mmap() */
+        if ((vma->vm_flags ^ vm_flags) & ~VM_CAN_NONLINEAR)
                 return 0;
         if (vma->vm_file != file)
                 return 0;
@@ -905,7 +903,7 @@ void vm_stat_account(struct mm_struct *mm, unsigned long flags,
 #endif /* CONFIG_PROC_FS */
 
 /*
- * The caller must hold down_write(current->mm->mmap_sem).
+ * The caller must hold down_write(&current->mm->mmap_sem).
  */
 
 unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
@@ -951,6 +949,24 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         if (mm->map_count > sysctl_max_map_count)
                 return -ENOMEM;
 
+        if (flags & MAP_HUGETLB) {
+                struct user_struct *user = NULL;
+                if (file)
+                        return -EINVAL;
+
+                /*
+                 * VM_NORESERVE is used because the reservations will be
+                 * taken when vm_ops->mmap() is called
+                 * A dummy user value is used because we are not locking
+                 * memory so no accounting is necessary
+                 */
+                len = ALIGN(len, huge_page_size(&default_hstate));
+                file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
+                                                &user, HUGETLB_ANONHUGE_INODE);
+                if (IS_ERR(file))
+                        return PTR_ERR(file);
+        }
+
         /* Obtain the address to map to. we verify (or select) it and ensure
          * that it represents a valid section of the address space.
          */
@@ -965,11 +981,9 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
                         mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
 
-        if (flags & MAP_LOCKED) {
+        if (flags & MAP_LOCKED)
                 if (!can_do_mlock())
                         return -EPERM;
-                vm_flags |= VM_LOCKED;
-        }
 
         /* mlock MCL_FUTURE? */
         if (vm_flags & VM_LOCKED) {
@@ -1195,21 +1209,21 @@ munmap_back:
                         goto unmap_and_free_vma;
                 if (vm_flags & VM_EXECUTABLE)
                         added_exe_file_vma(mm);
+
+                /* Can addr have changed??
+                 *
+                 * Answer: Yes, several device drivers can do it in their
+                 *         f_op->mmap method. -DaveM
+                 */
+                addr = vma->vm_start;
+                pgoff = vma->vm_pgoff;
+                vm_flags = vma->vm_flags;
         } else if (vm_flags & VM_SHARED) {
                 error = shmem_zero_setup(vma);
                 if (error)
                         goto free_vma;
         }
 
-        /* Can addr have changed??
-         *
-         * Answer: Yes, several device drivers can do it in their
-         *         f_op->mmap method. -DaveM
-         */
-        addr = vma->vm_start;
-        pgoff = vma->vm_pgoff;
-        vm_flags = vma->vm_flags;
-
         if (vma_wants_writenotify(vma))
                 vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED);
 
@@ -1220,7 +1234,7 @@ munmap_back:
         if (correct_wcount)
                 atomic_inc(&inode->i_writecount);
 out:
-        perf_counter_mmap(vma);
+        perf_event_mmap(vma);
 
         mm->total_vm += len >> PAGE_SHIFT;
         vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
@@ -2111,6 +2125,7 @@ void exit_mmap(struct mm_struct *mm)
         /* Use -1 here to ensure all VMAs in the mm are unmapped */
         end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
         vm_unacct_memory(nr_accounted);
+
         free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0);
         tlb_finish_mmu(tlb, 0, end);
 
@@ -2267,7 +2282,7 @@ static void special_mapping_close(struct vm_area_struct *vma)
 {
 }
 
-static struct vm_operations_struct special_mapping_vmops = {
+static const struct vm_operations_struct special_mapping_vmops = {
         .close = special_mapping_close,
         .fault = special_mapping_fault,
 };
@@ -2308,7 +2323,7 @@ int install_special_mapping(struct mm_struct *mm,
 
         mm->total_vm += len >> PAGE_SHIFT;
 
-        perf_counter_mmap(vma);
+        perf_event_mmap(vma);
 
         return 0;
 }
diff --git a/mm/mmu_context.c b/mm/mmu_context.c
new file mode 100644
index 000000000000..ded9081f4021
--- /dev/null
+++ b/mm/mmu_context.c
@@ -0,0 +1,58 @@
+/* Copyright (C) 2009 Red Hat, Inc.
+ *
+ * See ../COPYING for licensing terms.
+ */
+
+#include <linux/mm.h>
+#include <linux/mmu_context.h>
+#include <linux/sched.h>
+
+#include <asm/mmu_context.h>
+
+/*
+ * use_mm
+ *      Makes the calling kernel thread take on the specified
+ *      mm context.
+ *      Called by the retry thread execute retries within the
+ *      iocb issuer's mm context, so that copy_from/to_user
+ *      operations work seamlessly for aio.
+ *      (Note: this routine is intended to be called only
+ *      from a kernel thread context)
+ */
+void use_mm(struct mm_struct *mm)
+{
+        struct mm_struct *active_mm;
+        struct task_struct *tsk = current;
+
+        task_lock(tsk);
+        active_mm = tsk->active_mm;
+        if (active_mm != mm) {
+                atomic_inc(&mm->mm_count);
+                tsk->active_mm = mm;
+        }
+        tsk->mm = mm;
+        switch_mm(active_mm, mm, tsk);
+        task_unlock(tsk);
+
+        if (active_mm != mm)
+                mmdrop(active_mm);
+}
+
+/*
+ * unuse_mm
+ *      Reverses the effect of use_mm, i.e. releases the
+ *      specified mm context which was earlier taken on
+ *      by the calling kernel thread
+ *      (Note: this routine is intended to be called only
+ *      from a kernel thread context)
+ */
+void unuse_mm(struct mm_struct *mm)
+{
+        struct task_struct *tsk = current;
+
+        task_lock(tsk);
+        tsk->mm = NULL;
+        /* active_mm is still 'mm' */
+        enter_lazy_tlb(mm, tsk);
+        task_unlock(tsk);
+}
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 5f4ef0250bee..7e33f2cb3c77 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -99,6 +99,26 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
         return young;
 }
 
+void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
+                               pte_t pte)
+{
+        struct mmu_notifier *mn;
+        struct hlist_node *n;
+
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+                if (mn->ops->change_pte)
+                        mn->ops->change_pte(mn, mm, address, pte);
+                /*
+                 * Some drivers don't have change_pte,
+                 * so we must call invalidate_page in that case.
+                 */
+                else if (mn->ops->invalidate_page)
+                        mn->ops->invalidate_page(mn, mm, address);
+        }
+        rcu_read_unlock();
+}
+
 void __mmu_notifier_invalidate_page(struct mm_struct *mm,
                                           unsigned long address)
 {
diff --git a/mm/mprotect.c b/mm/mprotect.c
index d80311baeb2d..8bc969d8112d 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -23,7 +23,7 @@
 #include <linux/swapops.h>
 #include <linux/mmu_notifier.h>
 #include <linux/migrate.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/cacheflush.h>
@@ -300,7 +300,7 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
                 error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
                 if (error)
                         goto out;
-                perf_counter_mmap(vma);
+                perf_event_mmap(vma);
                 nstart = tmp;
 
                 if (nstart < prev->vm_end)
diff --git a/mm/mremap.c b/mm/mremap.c
index a39b7b91be46..97bff2547719 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -11,6 +11,7 @@
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/shm.h>
+#include <linux/ksm.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
 #include <linux/capability.h>
@@ -85,8 +86,8 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
         if (vma->vm_file) {
                 /*
                  * Subtle point from Rajesh Venkatasubramanian: before
-                 * moving file-based ptes, we must lock vmtruncate out,
-                 * since it might clean the dst vma before the src vma,
+                 * moving file-based ptes, we must lock truncate_pagecache
+                 * out, since it might clean the dst vma before the src vma,
                  * and we propagate stale pages into the dst afterward.
                  */
                 mapping = vma->vm_file->f_mapping;
@@ -174,6 +175,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
         unsigned long excess = 0;
         unsigned long hiwater_vm;
         int split = 0;
+        int err;
 
         /*
          * We'd prefer to avoid failure later on in do_munmap:
@@ -182,6 +184,18 @@ static unsigned long move_vma(struct vm_area_struct *vma,
         if (mm->map_count >= sysctl_max_map_count - 3)
                 return -ENOMEM;
 
+        /*
+         * Advise KSM to break any KSM pages in the area to be moved:
+         * it would be confusing if they were to turn up at the new
+         * location, where they happen to coincide with different KSM
+         * pages recently unmapped.  But leave vma->vm_flags as it was,
+         * so KSM can come around to merge on vma and new_vma afterwards.
+         */
+        err = ksm_madvise(vma, old_addr, old_addr + old_len,
+                                                MADV_UNMERGEABLE, &vm_flags);
+        if (err)
+                return err;
+
         new_pgoff = vma->vm_pgoff + ((old_addr - vma->vm_start) >> PAGE_SHIFT);
         new_vma = copy_vma(&vma, new_addr, new_len, new_pgoff);
         if (!new_vma)
diff --git a/mm/nommu.c b/mm/nommu.c
index 66e81e7e9fe9..5189b5aed8c0 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -33,6 +33,7 @@
 #include <asm/uaccess.h>
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
 #include "internal.h"
 
 static inline __attribute__((format(printf, 1, 2)))
@@ -56,12 +57,11 @@ void no_printk(const char *fmt, ...)
         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
 #endif
 
-#include "internal.h"
-
 void *high_memory;
 struct page *mem_map;
 unsigned long max_mapnr;
 unsigned long num_physpages;
+unsigned long highest_memmap_pfn;
 struct percpu_counter vm_committed_as;
 int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
 int sysctl_overcommit_ratio = 50; /* default is 50% */
@@ -79,50 +79,10 @@ static struct kmem_cache *vm_region_jar;
 struct rb_root nommu_region_tree = RB_ROOT;
 DECLARE_RWSEM(nommu_region_sem);
 
-struct vm_operations_struct generic_file_vm_ops = {
+const struct vm_operations_struct generic_file_vm_ops = {
 };
 
 /*
- * Handle all mappings that got truncated by a "truncate()"
- * system call.
- *
- * NOTE! We have to be ready to update the memory sharing
- * between the file and the memory map for a potential last
- * incomplete page.  Ugly, but necessary.
- */
-int vmtruncate(struct inode *inode, loff_t offset)
-{
-        struct address_space *mapping = inode->i_mapping;
-        unsigned long limit;
-
-        if (inode->i_size < offset)
-                goto do_expand;
-        i_size_write(inode, offset);
-
-        truncate_inode_pages(mapping, offset);
-        goto out_truncate;
-
-do_expand:
-        limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
-        if (limit != RLIM_INFINITY && offset > limit)
-                goto out_sig;
-        if (offset > inode->i_sb->s_maxbytes)
-                goto out;
-        i_size_write(inode, offset);
-
-out_truncate:
-        if (inode->i_op->truncate)
-                inode->i_op->truncate(inode);
-        return 0;
-out_sig:
-        send_sig(SIGXFSZ, current, 0);
-out:
-        return -EFBIG;
-}
-
-EXPORT_SYMBOL(vmtruncate);
-
-/*
  * Return the total memory allocated for this pointer, not
  * just what the caller asked for.
  *
@@ -170,21 +130,20 @@ unsigned int kobjsize(const void *objp)
 }
 
 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-                     unsigned long start, int nr_pages, int flags,
+                     unsigned long start, int nr_pages, unsigned int foll_flags,
                      struct page **pages, struct vm_area_struct **vmas)
 {
         struct vm_area_struct *vma;
         unsigned long vm_flags;
         int i;
-        int write = !!(flags & GUP_FLAGS_WRITE);
-        int force = !!(flags & GUP_FLAGS_FORCE);
-        int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
 
         /* calculate required read or write permissions.
-         * - if 'force' is set, we only require the "MAY" flags.
+         * If FOLL_FORCE is set, we only require the "MAY" flags.
          */
-        vm_flags  = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
-        vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
+        vm_flags  = (foll_flags & FOLL_WRITE) ?
+                        (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
+        vm_flags &= (foll_flags & FOLL_FORCE) ?
+                        (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
 
         for (i = 0; i < nr_pages; i++) {
                 vma = find_vma(mm, start);
@@ -192,8 +151,8 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         goto finish_or_fault;
 
                 /* protect what we can, including chardevs */
-                if (vma->vm_flags & (VM_IO | VM_PFNMAP) ||
-                    (!ignore && !(vm_flags & vma->vm_flags)))
+                if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+                    !(vm_flags & vma->vm_flags))
                         goto finish_or_fault;
 
                 if (pages) {
@@ -212,7 +171,6 @@ finish_or_fault:
         return i ? : -EFAULT;
 }
 
-
 /*
  * get a list of pages in an address range belonging to the specified process
  * and indicate the VMA that covers each page
@@ -227,9 +185,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
         int flags = 0;
 
         if (write)
-                flags |= GUP_FLAGS_WRITE;
+                flags |= FOLL_WRITE;
         if (force)
-                flags |= GUP_FLAGS_FORCE;
+                flags |= FOLL_FORCE;
 
         return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
 }
@@ -627,6 +585,22 @@ static void put_nommu_region(struct vm_region *region)
 }
 
 /*
+ * update protection on a vma
+ */
+static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
+{
+#ifdef CONFIG_MPU
+        struct mm_struct *mm = vma->vm_mm;
+        long start = vma->vm_start & PAGE_MASK;
+        while (start < vma->vm_end) {
+                protect_page(mm, start, flags);
+                start += PAGE_SIZE;
+        }
+        update_protections(mm);
+#endif
+}
+
+/*
  * add a VMA into a process's mm_struct in the appropriate place in the list
  * and tree and add to the address space's page tree also if not an anonymous
  * page
@@ -645,6 +619,8 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
         mm->map_count++;
         vma->vm_mm = mm;
 
+        protect_vma(vma, vma->vm_flags);
+
         /* add the VMA to the mapping */
         if (vma->vm_file) {
                 mapping = vma->vm_file->f_mapping;
@@ -707,6 +683,8 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
 
         kenter("%p", vma);
 
+        protect_vma(vma, 0);
+
         mm->map_count--;
         if (mm->mmap_cache == vma)
                 mm->mmap_cache = NULL;
@@ -848,7 +826,7 @@ static int validate_mmap_request(struct file *file,
         int ret;
 
         /* do the simple checks first */
-        if (flags & MAP_FIXED || addr) {
+        if (flags & MAP_FIXED) {
                 printk(KERN_DEBUG
                        "%d: Can't do fixed-address/overlay mmap of RAM\n",
                        current->pid);
@@ -1056,7 +1034,7 @@ static int do_mmap_shared_file(struct vm_area_struct *vma)
         ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
         if (ret == 0) {
                 vma->vm_region->vm_top = vma->vm_region->vm_end;
-                return ret;
+                return 0;
         }
         if (ret != -ENOSYS)
                 return ret;
@@ -1073,7 +1051,8 @@ static int do_mmap_shared_file(struct vm_area_struct *vma)
  */
 static int do_mmap_private(struct vm_area_struct *vma,
                            struct vm_region *region,
-                           unsigned long len)
+                           unsigned long len,
+                           unsigned long capabilities)
 {
         struct page *pages;
         unsigned long total, point, n, rlen;
@@ -1084,13 +1063,13 @@ static int do_mmap_private(struct vm_area_struct *vma,
          * shared mappings on devices or memory
          * - VM_MAYSHARE will be set if it may attempt to share
          */
-        if (vma->vm_file) {
+        if (capabilities & BDI_CAP_MAP_DIRECT) {
                 ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
                 if (ret == 0) {
                         /* shouldn't return success if we're not sharing */
                         BUG_ON(!(vma->vm_flags & VM_MAYSHARE));
                         vma->vm_region->vm_top = vma->vm_region->vm_end;
-                        return ret;
+                        return 0;
                 }
                 if (ret != -ENOSYS)
                         return ret;
@@ -1203,9 +1182,6 @@ unsigned long do_mmap_pgoff(struct file *file,
 
         kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff);
 
-        if (!(flags & MAP_FIXED))
-                addr = round_hint_to_min(addr);
-
         /* decide whether we should attempt the mapping, and if so what sort of
          * mapping */
         ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,
@@ -1215,6 +1191,9 @@ unsigned long do_mmap_pgoff(struct file *file,
                 return ret;
         }
 
+        /* we ignore the address hint */
+        addr = 0;
+
         /* we've determined that we can make the mapping, now translate what we
          * now know into VMA flags */
         vm_flags = determine_vm_flags(file, prot, flags, capabilities);
@@ -1328,7 +1307,7 @@ unsigned long do_mmap_pgoff(struct file *file,
                  * - this is the hook for quasi-memory character devices to
                  *   tell us the location of a shared mapping
                  */
-                if (file && file->f_op->get_unmapped_area) {
+                if (capabilities & BDI_CAP_MAP_DIRECT) {
                         addr = file->f_op->get_unmapped_area(file, addr, len,
                                                              pgoff, flags);
                         if (IS_ERR((void *) addr)) {
@@ -1352,15 +1331,17 @@ unsigned long do_mmap_pgoff(struct file *file,
         }
 
         vma->vm_region = region;
-        add_nommu_region(region);
 
-        /* set up the mapping */
+        /* set up the mapping
+         * - the region is filled in if BDI_CAP_MAP_DIRECT is still set
+         */
         if (file && vma->vm_flags & VM_SHARED)
                 ret = do_mmap_shared_file(vma);
         else
-                ret = do_mmap_private(vma, region, len);
+                ret = do_mmap_private(vma, region, len, capabilities);
         if (ret < 0)
-                goto error_put_region;
+                goto error_just_free;
+        add_nommu_region(region);
 
         /* okay... we have a mapping; now we have to register it */
         result = vma->vm_start;
@@ -1378,19 +1359,6 @@ share:
         kleave(" = %lx", result);
         return result;
 
-error_put_region:
-        __put_nommu_region(region);
-        if (vma) {
-                if (vma->vm_file) {
-                        fput(vma->vm_file);
-                        if (vma->vm_flags & VM_EXECUTABLE)
-                                removed_exe_file_vma(vma->vm_mm);
-                }
-                kmem_cache_free(vm_area_cachep, vma);
-        }
-        kleave(" = %d [pr]", ret);
-        return ret;
-
 error_just_free:
         up_write(&nommu_region_sem);
 error:
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index a7b2460e922b..ea2147dabba6 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -34,6 +34,23 @@ int sysctl_oom_dump_tasks;
 static DEFINE_SPINLOCK(zone_scan_lock);
 /* #define DEBUG */
 
+/*
+ * Is all threads of the target process nodes overlap ours?
+ */
+static int has_intersects_mems_allowed(struct task_struct *tsk)
+{
+        struct task_struct *t;
+
+        t = tsk;
+        do {
+                if (cpuset_mems_allowed_intersects(current, t))
+                        return 1;
+                t = next_thread(t);
+        } while (t != tsk);
+
+        return 0;
+}
+
 /**
  * badness - calculate a numeric value for how bad this task has been
  * @p: task struct of which task we should calculate
@@ -58,6 +75,13 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
         unsigned long points, cpu_time, run_time;
         struct mm_struct *mm;
         struct task_struct *child;
+        int oom_adj = p->signal->oom_adj;
+        struct task_cputime task_time;
+        unsigned long utime;
+        unsigned long stime;
+
+        if (oom_adj == OOM_DISABLE)
+                return 0;
 
         task_lock(p);
         mm = p->mm;
@@ -79,7 +103,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
         /*
          * swapoff can easily use up all memory, so kill those first.
          */
-        if (p->flags & PF_SWAPOFF)
+        if (p->flags & PF_OOM_ORIGIN)
                 return ULONG_MAX;
 
         /*
@@ -102,8 +126,11 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
          * of seconds. There is no particular reason for this other than
          * that it turned out to work very well in practice.
          */
-        cpu_time = (cputime_to_jiffies(p->utime) + cputime_to_jiffies(p->stime))
-                >> (SHIFT_HZ + 3);
+        thread_group_cputime(p, &task_time);
+        utime = cputime_to_jiffies(task_time.utime);
+        stime = cputime_to_jiffies(task_time.stime);
+        cpu_time = (utime + stime) >> (SHIFT_HZ + 3);
+
 
         if (uptime >= p->start_time.tv_sec)
                 run_time = (uptime - p->start_time.tv_sec) >> 10;
@@ -144,19 +171,19 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
          * because p may have allocated or otherwise mapped memory on
          * this node before. However it will be less likely.
          */
-        if (!cpuset_mems_allowed_intersects(current, p))
+        if (!has_intersects_mems_allowed(p))
                 points /= 8;
 
         /*
-         * Adjust the score by oomkilladj.
+         * Adjust the score by oom_adj.
          */
-        if (p->oomkilladj) {
-                if (p->oomkilladj > 0) {
+        if (oom_adj) {
+                if (oom_adj > 0) {
                         if (!points)
                                 points = 1;
-                        points <<= p->oomkilladj;
+                        points <<= oom_adj;
                 } else
-                        points >>= -(p->oomkilladj);
+                        points >>= -(oom_adj);
         }
 
 #ifdef DEBUG
@@ -200,13 +227,13 @@ static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,
 static struct task_struct *select_bad_process(unsigned long *ppoints,
                                                 struct mem_cgroup *mem)
 {
-        struct task_struct *g, *p;
+        struct task_struct *p;
         struct task_struct *chosen = NULL;
         struct timespec uptime;
         *ppoints = 0;
 
         do_posix_clock_monotonic_gettime(&uptime);
-        do_each_thread(g, p) {
+        for_each_process(p) {
                 unsigned long points;
 
                 /*
@@ -251,7 +278,7 @@ static struct task_struct *select_bad_process(unsigned long *ppoints,
                         *ppoints = ULONG_MAX;
                 }
 
-                if (p->oomkilladj == OOM_DISABLE)
+                if (p->signal->oom_adj == OOM_DISABLE)
                         continue;
 
                 points = badness(p, uptime.tv_sec);
@@ -259,7 +286,7 @@ static struct task_struct *select_bad_process(unsigned long *ppoints,
                         chosen = p;
                         *ppoints = points;
                 }
-        } while_each_thread(g, p);
+        }
 
         return chosen;
 }
@@ -304,7 +331,7 @@ static void dump_tasks(const struct mem_cgroup *mem)
                 }
                 printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d     %3d %s\n",
                        p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm,
-                       get_mm_rss(mm), (int)task_cpu(p), p->oomkilladj,
+                       get_mm_rss(mm), (int)task_cpu(p), p->signal->oom_adj,
                        p->comm);
                 task_unlock(p);
         } while_each_thread(g, p);
@@ -346,11 +373,6 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
 
 static int oom_kill_task(struct task_struct *p)
 {
-        struct mm_struct *mm;
-        struct task_struct *g, *q;
-
-        mm = p->mm;
-
         /* WARNING: mm may not be dereferenced since we did not obtain its
          * value from get_task_mm(p).  This is OK since all we need to do is
          * compare mm to q->mm below.
@@ -359,30 +381,11 @@ static int oom_kill_task(struct task_struct *p)
          * change to NULL at any time since we do not hold task_lock(p).
          * However, this is of no concern to us.
          */
-
-        if (mm == NULL)
+        if (!p->mm || p->signal->oom_adj == OOM_DISABLE)
                 return 1;
 
-        /*
-         * Don't kill the process if any threads are set to OOM_DISABLE
-         */
-        do_each_thread(g, q) {
-                if (q->mm == mm && q->oomkilladj == OOM_DISABLE)
-                        return 1;
-        } while_each_thread(g, q);
-
         __oom_kill_task(p, 1);
 
-        /*
-         * kill all processes that share the ->mm (i.e. all threads),
-         * but are in a different thread group. Don't let them have access
-         * to memory reserves though, otherwise we might deplete all memory.
-         */
-        do_each_thread(g, q) {
-                if (q->mm == mm && !same_thread_group(q, p))
-                        force_sig(SIGKILL, q);
-        } while_each_thread(g, q);
-
         return 0;
 }
 
@@ -394,8 +397,9 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 
         if (printk_ratelimit()) {
                 printk(KERN_WARNING "%s invoked oom-killer: "
-                        "gfp_mask=0x%x, order=%d, oomkilladj=%d\n",
-                        current->comm, gfp_mask, order, current->oomkilladj);
+                        "gfp_mask=0x%x, order=%d, oom_adj=%d\n",
+                        current->comm, gfp_mask, order,
+                        current->signal->oom_adj);
                 task_lock(current);
                 cpuset_print_task_mems_allowed(current);
                 task_unlock(current);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 81627ebcd313..2c5d79236ead 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -36,15 +36,6 @@
 #include <linux/pagevec.h>
 
 /*
- * The maximum number of pages to writeout in a single bdflush/kupdate
- * operation.  We do this so we don't hold I_SYNC against an inode for
- * enormous amounts of time, which would block a userspace task which has
- * been forced to throttle against that inode.  Also, the code reevaluates
- * the dirty each time it has written this many pages.
- */
-#define MAX_WRITEBACK_PAGES     1024
-
-/*
  * After a CPU has dirtied this many pages, balance_dirty_pages_ratelimited
  * will look to see if it needs to force writeback or throttling.
  */
@@ -53,18 +44,21 @@ static long ratelimit_pages = 32;
 /*
  * When balance_dirty_pages decides that the caller needs to perform some
  * non-background writeback, this is how many pages it will attempt to write.
- * It should be somewhat larger than RATELIMIT_PAGES to ensure that reasonably
+ * It should be somewhat larger than dirtied pages to ensure that reasonably
  * large amounts of I/O are submitted.
  */
-static inline long sync_writeback_pages(void)
+static inline long sync_writeback_pages(unsigned long dirtied)
 {
-        return ratelimit_pages + ratelimit_pages / 2;
+        if (dirtied < ratelimit_pages)
+                dirtied = ratelimit_pages;
+
+        return dirtied + dirtied / 2;
 }
 
 /* The following parameters are exported via /proc/sys/vm */
 
 /*
- * Start background writeback (via pdflush) at this percentage
+ * Start background writeback (via writeback threads) at this percentage
  */
 int dirty_background_ratio = 10;
 
@@ -117,8 +111,6 @@ EXPORT_SYMBOL(laptop_mode);
 /* End of sysctl-exported parameters */
 
 
-static void background_writeout(unsigned long _min_pages);
-
 /*
  * Scale the writeback cache size proportional to the relative writeout speeds.
  *
@@ -166,37 +158,37 @@ static void update_completion_period(void)
 }
 
 int dirty_background_ratio_handler(struct ctl_table *table, int write,
-                struct file *filp, void __user *buffer, size_t *lenp,
+                void __user *buffer, size_t *lenp,
                 loff_t *ppos)
 {
         int ret;
 
-        ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+        ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
         if (ret == 0 && write)
                 dirty_background_bytes = 0;
         return ret;
 }
 
 int dirty_background_bytes_handler(struct ctl_table *table, int write,
-                struct file *filp, void __user *buffer, size_t *lenp,
+                void __user *buffer, size_t *lenp,
                 loff_t *ppos)
 {
         int ret;
 
-        ret = proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos);
+        ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
         if (ret == 0 && write)
                 dirty_background_ratio = 0;
         return ret;
 }
 
 int dirty_ratio_handler(struct ctl_table *table, int write,
-                struct file *filp, void __user *buffer, size_t *lenp,
+                void __user *buffer, size_t *lenp,
                 loff_t *ppos)
 {
         int old_ratio = vm_dirty_ratio;
         int ret;
 
-        ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+        ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
         if (ret == 0 && write && vm_dirty_ratio != old_ratio) {
                 update_completion_period();
                 vm_dirty_bytes = 0;
@@ -206,13 +198,13 @@ int dirty_ratio_handler(struct ctl_table *table, int write,
 
 
 int dirty_bytes_handler(struct ctl_table *table, int write,
-                struct file *filp, void __user *buffer, size_t *lenp,
+                void __user *buffer, size_t *lenp,
                 loff_t *ppos)
 {
         unsigned long old_bytes = vm_dirty_bytes;
         int ret;
 
-        ret = proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos);
+        ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
         if (ret == 0 && write && vm_dirty_bytes != old_bytes) {
                 update_completion_period();
                 vm_dirty_ratio = 0;
@@ -320,15 +312,13 @@ static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty)
 /*
  *
  */
-static DEFINE_SPINLOCK(bdi_lock);
 static unsigned int bdi_min_ratio;
 
 int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
 {
         int ret = 0;
-        unsigned long flags;
 
-        spin_lock_irqsave(&bdi_lock, flags);
+        spin_lock_bh(&bdi_lock);
         if (min_ratio > bdi->max_ratio) {
                 ret = -EINVAL;
         } else {
@@ -340,27 +330,26 @@ int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
                         ret = -EINVAL;
                 }
         }
-        spin_unlock_irqrestore(&bdi_lock, flags);
+        spin_unlock_bh(&bdi_lock);
 
         return ret;
 }
 
 int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
 {
-        unsigned long flags;
         int ret = 0;
 
         if (max_ratio > 100)
                 return -EINVAL;
 
-        spin_lock_irqsave(&bdi_lock, flags);
+        spin_lock_bh(&bdi_lock);
         if (bdi->min_ratio > max_ratio) {
                 ret = -EINVAL;
         } else {
                 bdi->max_ratio = max_ratio;
                 bdi->max_prop_frac = (PROP_FRAC_BASE * max_ratio) / 100;
         }
-        spin_unlock_irqrestore(&bdi_lock, flags);
+        spin_unlock_bh(&bdi_lock);
 
         return ret;
 }
@@ -394,7 +383,8 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
                 struct zone *z =
                         &NODE_DATA(node)->node_zones[ZONE_HIGHMEM];
 
-                x += zone_page_state(z, NR_FREE_PAGES) + zone_lru_pages(z);
+                x += zone_page_state(z, NR_FREE_PAGES) +
+                     zone_reclaimable_pages(z);
         }
         /*
          * Make sure that the number of highmem pages is never larger
@@ -418,7 +408,7 @@ unsigned long determine_dirtyable_memory(void)
 {
         unsigned long x;
 
-        x = global_page_state(NR_FREE_PAGES) + global_lru_pages();
+        x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
 
         if (!vm_highmem_is_dirtyable)
                 x -= highmem_dirtyable_memory(x);
@@ -487,10 +477,11 @@ get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
  * balance_dirty_pages() must be called by processes which are generating dirty
  * data.  It looks at the number of dirty pages in the machine and will force
  * the caller to perform writeback if the system is over `vm_dirty_ratio'.
- * If we're over `background_thresh' then pdflush is woken to perform some
- * writeout.
+ * If we're over `background_thresh' then the writeback threads are woken to
+ * perform some writeout.
  */
-static void balance_dirty_pages(struct address_space *mapping)
+static void balance_dirty_pages(struct address_space *mapping,
+                                unsigned long write_chunk)
 {
         long nr_reclaimable, bdi_nr_reclaimable;
         long nr_writeback, bdi_nr_writeback;
@@ -498,7 +489,7 @@ static void balance_dirty_pages(struct address_space *mapping)
         unsigned long dirty_thresh;
         unsigned long bdi_thresh;
         unsigned long pages_written = 0;
-        unsigned long write_chunk = sync_writeback_pages();
+        unsigned long pause = 1;
 
         struct backing_dev_info *bdi = mapping->backing_dev_info;
 
@@ -546,7 +537,7 @@ static void balance_dirty_pages(struct address_space *mapping)
                  * up.
                  */
                 if (bdi_nr_reclaimable > bdi_thresh) {
-                        writeback_inodes(&wbc);
+                        writeback_inodes_wbc(&wbc);
                         pages_written += write_chunk - wbc.nr_to_write;
                         get_dirty_limits(&background_thresh, &dirty_thresh,
                                        &bdi_thresh, bdi);
@@ -575,7 +566,16 @@ static void balance_dirty_pages(struct address_space *mapping)
                 if (pages_written >= write_chunk)
                         break;          /* We've done our duty */
 
-                congestion_wait(BLK_RW_ASYNC, HZ/10);
+                __set_current_state(TASK_INTERRUPTIBLE);
+                io_schedule_timeout(pause);
+
+                /*
+                 * Increase the delay for each loop, up to our previous
+                 * default of taking a 100ms nap.
+                 */
+                pause <<= 1;
+                if (pause > HZ / 10)
+                        pause = HZ / 10;
         }
 
         if (bdi_nr_reclaimable + bdi_nr_writeback < bdi_thresh &&
@@ -583,7 +583,7 @@ static void balance_dirty_pages(struct address_space *mapping)
                 bdi->dirty_exceeded = 0;
 
         if (writeback_in_progress(bdi))
-                return;         /* pdflush is already working this queue */
+                return;
 
         /*
          * In laptop mode, we wait until hitting the higher threshold before
@@ -594,10 +594,10 @@ static void balance_dirty_pages(struct address_space *mapping)
          * background_thresh, to keep the amount of dirty memory low.
          */
         if ((laptop_mode && pages_written) ||
-                        (!laptop_mode && (global_page_state(NR_FILE_DIRTY)
-                                          + global_page_state(NR_UNSTABLE_NFS)
+            (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
+                               + global_page_state(NR_UNSTABLE_NFS))
                                           > background_thresh)))
-                pdflush_operation(background_writeout, 0);
+                bdi_start_writeback(bdi, NULL, 0);
 }
 
 void set_page_dirty_balance(struct page *page, int page_mkwrite)
@@ -610,6 +610,8 @@ void set_page_dirty_balance(struct page *page, int page_mkwrite)
         }
 }
 
+static DEFINE_PER_CPU(unsigned long, bdp_ratelimits) = 0;
+
 /**
  * balance_dirty_pages_ratelimited_nr - balance dirty memory state
  * @mapping: address_space which was dirtied
@@ -627,7 +629,6 @@ void set_page_dirty_balance(struct page *page, int page_mkwrite)
 void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
                                         unsigned long nr_pages_dirtied)
 {
-        static DEFINE_PER_CPU(unsigned long, ratelimits) = 0;
         unsigned long ratelimit;
         unsigned long *p;
 
@@ -640,12 +641,13 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
          * tasks in balance_dirty_pages(). Period.
          */
         preempt_disable();
-        p =  &__get_cpu_var(ratelimits);
+        p =  &__get_cpu_var(bdp_ratelimits);
         *p += nr_pages_dirtied;
         if (unlikely(*p >= ratelimit)) {
+                ratelimit = sync_writeback_pages(*p);
                 *p = 0;
                 preempt_enable();
-                balance_dirty_pages(mapping);
+                balance_dirty_pages(mapping, ratelimit);
                 return;
         }
         preempt_enable();
@@ -681,153 +683,35 @@ void throttle_vm_writeout(gfp_t gfp_mask)
         }
 }
 
-/*
- * writeback at least _min_pages, and keep writing until the amount of dirty
- * memory is less than the background threshold, or until we're all clean.
- */
-static void background_writeout(unsigned long _min_pages)
-{
-        long min_pages = _min_pages;
-        struct writeback_control wbc = {
-                .bdi            = NULL,
-                .sync_mode      = WB_SYNC_NONE,
-                .older_than_this = NULL,
-                .nr_to_write    = 0,
-                .nonblocking    = 1,
-                .range_cyclic   = 1,
-        };
-
-        for ( ; ; ) {
-                unsigned long background_thresh;
-                unsigned long dirty_thresh;
-
-                get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL);
-                if (global_page_state(NR_FILE_DIRTY) +
-                        global_page_state(NR_UNSTABLE_NFS) < background_thresh
-                                && min_pages <= 0)
-                        break;
-                wbc.more_io = 0;
-                wbc.encountered_congestion = 0;
-                wbc.nr_to_write = MAX_WRITEBACK_PAGES;
-                wbc.pages_skipped = 0;
-                writeback_inodes(&wbc);
-                min_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
-                if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) {
-                        /* Wrote less than expected */
-                        if (wbc.encountered_congestion || wbc.more_io)
-                                congestion_wait(BLK_RW_ASYNC, HZ/10);
-                        else
-                                break;
-                }
-        }
-}
-
-/*
- * Start writeback of `nr_pages' pages.  If `nr_pages' is zero, write back
- * the whole world.  Returns 0 if a pdflush thread was dispatched.  Returns
- * -1 if all pdflush threads were busy.
- */
-int wakeup_pdflush(long nr_pages)
-{
-        if (nr_pages == 0)
-                nr_pages = global_page_state(NR_FILE_DIRTY) +
-                                global_page_state(NR_UNSTABLE_NFS);
-        return pdflush_operation(background_writeout, nr_pages);
-}
-
-static void wb_timer_fn(unsigned long unused);
 static void laptop_timer_fn(unsigned long unused);
 
-static DEFINE_TIMER(wb_timer, wb_timer_fn, 0, 0);
 static DEFINE_TIMER(laptop_mode_wb_timer, laptop_timer_fn, 0, 0);
 
 /*
- * Periodic writeback of "old" data.
- *
- * Define "old": the first time one of an inode's pages is dirtied, we mark the
- * dirtying-time in the inode's address_space.  So this periodic writeback code
- * just walks the superblock inode list, writing back any inodes which are
- * older than a specific point in time.
- *
- * Try to run once per dirty_writeback_interval.  But if a writeback event
- * takes longer than a dirty_writeback_interval interval, then leave a
- * one-second gap.
- *
- * older_than_this takes precedence over nr_to_write.  So we'll only write back
- * all dirty pages if they are all attached to "old" mappings.
- */
-static void wb_kupdate(unsigned long arg)
-{
-        unsigned long oldest_jif;
-        unsigned long start_jif;
-        unsigned long next_jif;
-        long nr_to_write;
-        struct writeback_control wbc = {
-                .bdi            = NULL,
-                .sync_mode      = WB_SYNC_NONE,
-                .older_than_this = &oldest_jif,
-                .nr_to_write    = 0,
-                .nonblocking    = 1,
-                .for_kupdate    = 1,
-                .range_cyclic   = 1,
-        };
-
-        sync_supers();
-
-        oldest_jif = jiffies - msecs_to_jiffies(dirty_expire_interval * 10);
-        start_jif = jiffies;
-        next_jif = start_jif + msecs_to_jiffies(dirty_writeback_interval * 10);
-        nr_to_write = global_page_state(NR_FILE_DIRTY) +
-                        global_page_state(NR_UNSTABLE_NFS) +
-                        (inodes_stat.nr_inodes - inodes_stat.nr_unused);
-        while (nr_to_write > 0) {
-                wbc.more_io = 0;
-                wbc.encountered_congestion = 0;
-                wbc.nr_to_write = MAX_WRITEBACK_PAGES;
-                writeback_inodes(&wbc);
-                if (wbc.nr_to_write > 0) {
-                        if (wbc.encountered_congestion || wbc.more_io)
-                                congestion_wait(BLK_RW_ASYNC, HZ/10);
-                        else
-                                break;  /* All the old data is written */
-                }
-                nr_to_write -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
-        }
-        if (time_before(next_jif, jiffies + HZ))
-                next_jif = jiffies + HZ;
-        if (dirty_writeback_interval)
-                mod_timer(&wb_timer, next_jif);
-}
-
-/*
  * sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
  */
 int dirty_writeback_centisecs_handler(ctl_table *table, int write,
-        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+        void __user *buffer, size_t *length, loff_t *ppos)
 {
-        proc_dointvec(table, write, file, buffer, length, ppos);
-        if (dirty_writeback_interval)
-                mod_timer(&wb_timer, jiffies +
-                        msecs_to_jiffies(dirty_writeback_interval * 10));
-        else
-                del_timer(&wb_timer);
+        proc_dointvec(table, write, buffer, length, ppos);
         return 0;
 }
 
-static void wb_timer_fn(unsigned long unused)
+static void do_laptop_sync(struct work_struct *work)
 {
-        if (pdflush_operation(wb_kupdate, 0) < 0)
-                mod_timer(&wb_timer, jiffies + HZ); /* delay 1 second */
-}
-
-static void laptop_flush(unsigned long unused)
-{
-        sys_sync();
+        wakeup_flusher_threads(0);
+        kfree(work);
 }
 
 static void laptop_timer_fn(unsigned long unused)
 {
-        pdflush_operation(laptop_flush, 0);
+        struct work_struct *work;
+
+        work = kmalloc(sizeof(*work), GFP_ATOMIC);
+        if (work) {
+                INIT_WORK(work, do_laptop_sync);
+                schedule_work(work);
+        }
 }
 
 /*
@@ -910,8 +794,6 @@ void __init page_writeback_init(void)
 {
         int shift;
 
-        mod_timer(&wb_timer,
-                  jiffies + msecs_to_jiffies(dirty_writeback_interval * 10));
         writeback_set_ratelimit();
         register_cpu_notifier(&ratelimit_nb);
 
@@ -1145,12 +1027,10 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
 
         if (wbc->nr_to_write <= 0)
                 return 0;
-        wbc->for_writepages = 1;
         if (mapping->a_ops->writepages)
                 ret = mapping->a_ops->writepages(mapping, wbc);
         else
                 ret = generic_writepages(mapping, wbc);
-        wbc->for_writepages = 0;
         return ret;
 }
 
@@ -1274,6 +1154,13 @@ int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
 EXPORT_SYMBOL(redirty_page_for_writepage);
 
 /*
+ * Dirty a page.
+ *
+ * For pages with a mapping this should be done under the page lock
+ * for the benefit of asynchronous memory errors who prefer a consistent
+ * dirty state. This rule can be broken in some special cases,
+ * but should be better not to.
+ *
  * If the mapping doesn't provide a set_page_dirty a_op, then
  * just fall through and assume that it wants buffer_heads.
  */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a0de15f46987..bf720550b44d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -48,6 +48,7 @@
 #include <linux/page_cgroup.h>
 #include <linux/debugobjects.h>
 #include <linux/kmemleak.h>
+#include <trace/events/kmem.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -71,7 +72,6 @@ EXPORT_SYMBOL(node_states);
 
 unsigned long totalram_pages __read_mostly;
 unsigned long totalreserve_pages __read_mostly;
-unsigned long highest_memmap_pfn __read_mostly;
 int percpu_pagelist_fraction;
 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
 
@@ -123,8 +123,8 @@ static char * const zone_names[MAX_NR_ZONES] = {
 
 int min_free_kbytes = 1024;
 
-unsigned long __meminitdata nr_kernel_pages;
-unsigned long __meminitdata nr_all_pages;
+static unsigned long __meminitdata nr_kernel_pages;
+static unsigned long __meminitdata nr_all_pages;
 static unsigned long __meminitdata dma_reserve;
 
 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
@@ -234,6 +234,12 @@ static void bad_page(struct page *page)
         static unsigned long nr_shown;
         static unsigned long nr_unshown;
 
+        /* Don't complain about poisoned pages */
+        if (PageHWPoison(page)) {
+                __ClearPageBuddy(page);
+                return;
+        }
+
         /*
          * Allow a burst of 60 reports, then keep quiet for that minute;
          * or allow a steady drip of one report per second.
@@ -510,7 +516,7 @@ static inline int free_pages_check(struct page *page)
 }
 
 /*
- * Frees a list of pages. 
+ * Frees a number of pages from the PCP lists
  * Assumes all pages on list are in same zone, and of same order.
  * count is the number of pages to free.
  *
@@ -520,22 +526,42 @@ static inline int free_pages_check(struct page *page)
  * And clear the zone's pages_scanned counter, to hold off the "all pages are
  * pinned" detection logic.
  */
-static void free_pages_bulk(struct zone *zone, int count,
-                                        struct list_head *list, int order)
+static void free_pcppages_bulk(struct zone *zone, int count,
+                                        struct per_cpu_pages *pcp)
 {
+        int migratetype = 0;
+        int batch_free = 0;
+
         spin_lock(&zone->lock);
         zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
         zone->pages_scanned = 0;
 
-        __mod_zone_page_state(zone, NR_FREE_PAGES, count << order);
-        while (count--) {
+        __mod_zone_page_state(zone, NR_FREE_PAGES, count);
+        while (count) {
                 struct page *page;
+                struct list_head *list;
 
-                VM_BUG_ON(list_empty(list));
-                page = list_entry(list->prev, struct page, lru);
-                /* have to delete it as __free_one_page list manipulates */
-                list_del(&page->lru);
-                __free_one_page(page, zone, order, page_private(page));
+                /*
+                 * Remove pages from lists in a round-robin fashion. A
+                 * batch_free count is maintained that is incremented when an
+                 * empty list is encountered.  This is so more pages are freed
+                 * off fuller lists instead of spinning excessively around empty
+                 * lists
+                 */
+                do {
+                        batch_free++;
+                        if (++migratetype == MIGRATE_PCPTYPES)
+                                migratetype = 0;
+                        list = &pcp->lists[migratetype];
+                } while (list_empty(list));
+
+                do {
+                        page = list_entry(list->prev, struct page, lru);
+                        /* must delete as __free_one_page list manipulates */
+                        list_del(&page->lru);
+                        __free_one_page(page, zone, 0, migratetype);
+                        trace_mm_page_pcpu_drain(page, 0, migratetype);
+                } while (--count && --batch_free && !list_empty(list));
         }
         spin_unlock(&zone->lock);
 }
@@ -557,7 +583,7 @@ static void __free_pages_ok(struct page *page, unsigned int order)
         unsigned long flags;
         int i;
         int bad = 0;
-        int wasMlocked = TestClearPageMlocked(page);
+        int wasMlocked = __TestClearPageMlocked(page);
 
         kmemcheck_free_shadow(page, order);
 
@@ -646,7 +672,7 @@ static inline void expand(struct zone *zone, struct page *page,
 /*
  * This page is about to be returned from the page allocator
  */
-static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
+static inline int check_new_page(struct page *page)
 {
         if (unlikely(page_mapcount(page) |
                 (page->mapping != NULL)  |
@@ -655,6 +681,18 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
                 bad_page(page);
                 return 1;
         }
+        return 0;
+}
+
+static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
+{
+        int i;
+
+        for (i = 0; i < (1 << order); i++) {
+                struct page *p = page + i;
+                if (unlikely(check_new_page(p)))
+                        return 1;
+        }
 
         set_page_private(page, 0);
         set_page_refcounted(page);
@@ -783,6 +821,17 @@ static int move_freepages_block(struct zone *zone, struct page *page,
         return move_freepages(zone, start_page, end_page, migratetype);
 }
 
+static void change_pageblock_range(struct page *pageblock_page,
+                                        int start_order, int migratetype)
+{
+        int nr_pageblocks = 1 << (start_order - pageblock_order);
+
+        while (nr_pageblocks--) {
+                set_pageblock_migratetype(pageblock_page, migratetype);
+                pageblock_page += pageblock_nr_pages;
+        }
+}
+
 /* Remove an element from the buddy allocator from the fallback list */
 static inline struct page *
 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
@@ -836,11 +885,16 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
                         list_del(&page->lru);
                         rmv_page_order(page);
 
-                        if (current_order == pageblock_order)
-                                set_pageblock_migratetype(page,
+                        /* Take ownership for orders >= pageblock_order */
+                        if (current_order >= pageblock_order)
+                                change_pageblock_range(page, current_order,
                                                         start_migratetype);
 
                         expand(zone, page, order, current_order, area, migratetype);
+
+                        trace_mm_page_alloc_extfrag(page, order, current_order,
+                                start_migratetype, migratetype);
+
                         return page;
                 }
         }
@@ -874,6 +928,7 @@ retry_reserve:
                 }
         }
 
+        trace_mm_page_alloc_zone_locked(page, order, migratetype);
         return page;
 }
 
@@ -934,7 +989,7 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
                 to_drain = pcp->batch;
         else
                 to_drain = pcp->count;
-        free_pages_bulk(zone, to_drain, &pcp->list, 0);
+        free_pcppages_bulk(zone, to_drain, pcp);
         pcp->count -= to_drain;
         local_irq_restore(flags);
 }
@@ -960,7 +1015,7 @@ static void drain_pages(unsigned int cpu)
 
                 pcp = &pset->pcp;
                 local_irq_save(flags);
-                free_pages_bulk(zone, pcp->count, &pcp->list, 0);
+                free_pcppages_bulk(zone, pcp->count, pcp);
                 pcp->count = 0;
                 local_irq_restore(flags);
         }
@@ -1026,7 +1081,8 @@ static void free_hot_cold_page(struct page *page, int cold)
         struct zone *zone = page_zone(page);
         struct per_cpu_pages *pcp;
         unsigned long flags;
-        int wasMlocked = TestClearPageMlocked(page);
+        int migratetype;
+        int wasMlocked = __TestClearPageMlocked(page);
 
         kmemcheck_free_shadow(page, 0);
 
@@ -1043,35 +1099,49 @@ static void free_hot_cold_page(struct page *page, int cold)
         kernel_map_pages(page, 1, 0);
 
         pcp = &zone_pcp(zone, get_cpu())->pcp;
-        set_page_private(page, get_pageblock_migratetype(page));
+        migratetype = get_pageblock_migratetype(page);
+        set_page_private(page, migratetype);
         local_irq_save(flags);
         if (unlikely(wasMlocked))
                 free_page_mlock(page);
         __count_vm_event(PGFREE);
 
+        /*
+         * We only track unmovable, reclaimable and movable on pcp lists.
+         * Free ISOLATE pages back to the allocator because they are being
+         * offlined but treat RESERVE as movable pages so we can get those
+         * areas back if necessary. Otherwise, we may have to free
+         * excessively into the page allocator
+         */
+        if (migratetype >= MIGRATE_PCPTYPES) {
+                if (unlikely(migratetype == MIGRATE_ISOLATE)) {
+                        free_one_page(zone, page, 0, migratetype);
+                        goto out;
+                }
+                migratetype = MIGRATE_MOVABLE;
+        }
+
         if (cold)
-                list_add_tail(&page->lru, &pcp->list);
+                list_add_tail(&page->lru, &pcp->lists[migratetype]);
         else
-                list_add(&page->lru, &pcp->list);
+                list_add(&page->lru, &pcp->lists[migratetype]);
         pcp->count++;
         if (pcp->count >= pcp->high) {
-                free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
+                free_pcppages_bulk(zone, pcp->batch, pcp);
                 pcp->count -= pcp->batch;
         }
+
+out:
         local_irq_restore(flags);
         put_cpu();
 }
 
 void free_hot_page(struct page *page)
 {
+        trace_mm_page_free_direct(page, 0);
         free_hot_cold_page(page, 0);
 }
         
-void free_cold_page(struct page *page)
-{
-        free_hot_cold_page(page, 1);
-}
-
 /*
  * split_page takes a non-compound higher-order page, and splits it into
  * n (1<<order) sub-pages: page[0..n]
@@ -1119,35 +1189,23 @@ again:
         cpu  = get_cpu();
         if (likely(order == 0)) {
                 struct per_cpu_pages *pcp;
+                struct list_head *list;
 
                 pcp = &zone_pcp(zone, cpu)->pcp;
+                list = &pcp->lists[migratetype];
                 local_irq_save(flags);
-                if (!pcp->count) {
-                        pcp->count = rmqueue_bulk(zone, 0,
-                                        pcp->batch, &pcp->list,
+                if (list_empty(list)) {
+                        pcp->count += rmqueue_bulk(zone, 0,
+                                        pcp->batch, list,
                                         migratetype, cold);
-                        if (unlikely(!pcp->count))
+                        if (unlikely(list_empty(list)))
                                 goto failed;
                 }
 
-                /* Find a page of the appropriate migrate type */
-                if (cold) {
-                        list_for_each_entry_reverse(page, &pcp->list, lru)
-                                if (page_private(page) == migratetype)
-                                        break;
-                } else {
-                        list_for_each_entry(page, &pcp->list, lru)
-                                if (page_private(page) == migratetype)
-                                        break;
-                }
-
-                /* Allocate more to the pcp list if necessary */
-                if (unlikely(&page->lru == &pcp->list)) {
-                        pcp->count += rmqueue_bulk(zone, 0,
-                                        pcp->batch, &pcp->list,
-                                        migratetype, cold);
-                        page = list_entry(pcp->list.next, struct page, lru);
-                }
+                if (cold)
+                        page = list_entry(list->prev, struct page, lru);
+                else
+                        page = list_entry(list->next, struct page, lru);
 
                 list_del(&page->lru);
                 pcp->count--;
@@ -1627,10 +1685,6 @@ __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
 
         /* We now go into synchronous reclaim */
         cpuset_memory_pressure_bump();
-
-        /*
-         * The task's cpuset might have expanded its set of allowable nodes
-         */
         p->flags |= PF_MEMALLOC;
         lockdep_set_current_reclaim_state(gfp_mask);
         reclaim_state.reclaimed_slab = 0;
@@ -1765,6 +1819,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
 
         wake_all_kswapd(order, zonelist, high_zoneidx);
 
+restart:
         /*
          * OK, we're below the kswapd watermark and have kicked background
          * reclaim. Now things get more complex, so set up alloc_flags according
@@ -1772,7 +1827,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
          */
         alloc_flags = gfp_to_alloc_flags(gfp_mask);
 
-restart:
         /* This is the last chance, in general, before the goto nopage. */
         page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
                         high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
@@ -1907,6 +1961,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
                                 zonelist, high_zoneidx, nodemask,
                                 preferred_zone, migratetype);
 
+        trace_mm_page_alloc(page, order, gfp_mask, migratetype);
         return page;
 }
 EXPORT_SYMBOL(__alloc_pages_nodemask);
@@ -1916,44 +1971,41 @@ EXPORT_SYMBOL(__alloc_pages_nodemask);
  */
 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
 {
-        struct page * page;
+        struct page *page;
+
+        /*
+         * __get_free_pages() returns a 32-bit address, which cannot represent
+         * a highmem page
+         */
+        VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
+
         page = alloc_pages(gfp_mask, order);
         if (!page)
                 return 0;
         return (unsigned long) page_address(page);
 }
-
 EXPORT_SYMBOL(__get_free_pages);
 
 unsigned long get_zeroed_page(gfp_t gfp_mask)
 {
-        struct page * page;
-
-        /*
-         * get_zeroed_page() returns a 32-bit address, which cannot represent
-         * a highmem page
-         */
-        VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
-
-        page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
-        if (page)
-                return (unsigned long) page_address(page);
-        return 0;
+        return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
 }
-
 EXPORT_SYMBOL(get_zeroed_page);
 
 void __pagevec_free(struct pagevec *pvec)
 {
         int i = pagevec_count(pvec);
 
-        while (--i >= 0)
+        while (--i >= 0) {
+                trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
                 free_hot_cold_page(pvec->pages[i], pvec->cold);
+        }
 }
 
 void __free_pages(struct page *page, unsigned int order)
 {
         if (put_page_testzero(page)) {
+                trace_mm_page_free_direct(page, order);
                 if (order == 0)
                         free_hot_page(page);
                 else
@@ -2128,23 +2180,28 @@ void show_free_areas(void)
                 }
         }
 
-        printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
-                " inactive_file:%lu"
+        printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
+                " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
                 " unevictable:%lu"
-                " dirty:%lu writeback:%lu unstable:%lu\n"
-                " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
+                " dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n"
+                " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
+                " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
                 global_page_state(NR_ACTIVE_ANON),
-                global_page_state(NR_ACTIVE_FILE),
                 global_page_state(NR_INACTIVE_ANON),
+                global_page_state(NR_ISOLATED_ANON),
+                global_page_state(NR_ACTIVE_FILE),
                 global_page_state(NR_INACTIVE_FILE),
+                global_page_state(NR_ISOLATED_FILE),
                 global_page_state(NR_UNEVICTABLE),
                 global_page_state(NR_FILE_DIRTY),
                 global_page_state(NR_WRITEBACK),
                 global_page_state(NR_UNSTABLE_NFS),
+                nr_blockdev_pages(),
                 global_page_state(NR_FREE_PAGES),
-                global_page_state(NR_SLAB_RECLAIMABLE) +
-                        global_page_state(NR_SLAB_UNRECLAIMABLE),
+                global_page_state(NR_SLAB_RECLAIMABLE),
+                global_page_state(NR_SLAB_UNRECLAIMABLE),
                 global_page_state(NR_FILE_MAPPED),
+                global_page_state(NR_SHMEM),
                 global_page_state(NR_PAGETABLE),
                 global_page_state(NR_BOUNCE));
 
@@ -2162,7 +2219,21 @@ void show_free_areas(void)
                         " active_file:%lukB"
                         " inactive_file:%lukB"
                         " unevictable:%lukB"
+                        " isolated(anon):%lukB"
+                        " isolated(file):%lukB"
                         " present:%lukB"
+                        " mlocked:%lukB"
+                        " dirty:%lukB"
+                        " writeback:%lukB"
+                        " mapped:%lukB"
+                        " shmem:%lukB"
+                        " slab_reclaimable:%lukB"
+                        " slab_unreclaimable:%lukB"
+                        " kernel_stack:%lukB"
+                        " pagetables:%lukB"
+                        " unstable:%lukB"
+                        " bounce:%lukB"
+                        " writeback_tmp:%lukB"
                         " pages_scanned:%lu"
                         " all_unreclaimable? %s"
                         "\n",
@@ -2176,7 +2247,22 @@ void show_free_areas(void)
                         K(zone_page_state(zone, NR_ACTIVE_FILE)),
                         K(zone_page_state(zone, NR_INACTIVE_FILE)),
                         K(zone_page_state(zone, NR_UNEVICTABLE)),
+                        K(zone_page_state(zone, NR_ISOLATED_ANON)),
+                        K(zone_page_state(zone, NR_ISOLATED_FILE)),
                         K(zone->present_pages),
+                        K(zone_page_state(zone, NR_MLOCK)),
+                        K(zone_page_state(zone, NR_FILE_DIRTY)),
+                        K(zone_page_state(zone, NR_WRITEBACK)),
+                        K(zone_page_state(zone, NR_FILE_MAPPED)),
+                        K(zone_page_state(zone, NR_SHMEM)),
+                        K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
+                        K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
+                        zone_page_state(zone, NR_KERNEL_STACK) *
+                                THREAD_SIZE / 1024,
+                        K(zone_page_state(zone, NR_PAGETABLE)),
+                        K(zone_page_state(zone, NR_UNSTABLE_NFS)),
+                        K(zone_page_state(zone, NR_BOUNCE)),
+                        K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
                         zone->pages_scanned,
                         (zone_is_all_unreclaimable(zone) ? "yes" : "no")
                         );
@@ -2305,7 +2391,7 @@ early_param("numa_zonelist_order", setup_numa_zonelist_order);
  * sysctl handler for numa_zonelist_order
  */
 int numa_zonelist_order_handler(ctl_table *table, int write,
-                struct file *file, void __user *buffer, size_t *length,
+                void __user *buffer, size_t *length,
                 loff_t *ppos)
 {
         char saved_string[NUMA_ZONELIST_ORDER_LEN];
@@ -2314,7 +2400,7 @@ int numa_zonelist_order_handler(ctl_table *table, int write,
         if (write)
                 strncpy(saved_string, (char*)table->data,
                         NUMA_ZONELIST_ORDER_LEN);
-        ret = proc_dostring(table, write, file, buffer, length, ppos);
+        ret = proc_dostring(table, write, buffer, length, ppos);
         if (ret)
                 return ret;
         if (write) {
@@ -2783,7 +2869,8 @@ static void setup_zone_migrate_reserve(struct zone *zone)
 {
         unsigned long start_pfn, pfn, end_pfn;
         struct page *page;
-        unsigned long reserve, block_migratetype;
+        unsigned long block_migratetype;
+        int reserve;
 
         /* Get the start pfn, end pfn and the number of blocks to reserve */
         start_pfn = zone->zone_start_pfn;
@@ -2791,6 +2878,15 @@ static void setup_zone_migrate_reserve(struct zone *zone)
         reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
                                                         pageblock_order;
 
+        /*
+         * Reserve blocks are generally in place to help high-order atomic
+         * allocations that are short-lived. A min_free_kbytes value that
+         * would result in more than 2 reserve blocks for atomic allocations
+         * is assumed to be in place to help anti-fragmentation for the
+         * future allocation of hugepages at runtime.
+         */
+        reserve = min(2, reserve);
+
         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
                 if (!pfn_valid(pfn))
                         continue;
@@ -2961,6 +3057,7 @@ static int zone_batchsize(struct zone *zone)
 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
 {
         struct per_cpu_pages *pcp;
+        int migratetype;
 
         memset(p, 0, sizeof(*p));
 
@@ -2968,7 +3065,8 @@ static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
         pcp->count = 0;
         pcp->high = 6 * batch;
         pcp->batch = max(1UL, 1 * batch);
-        INIT_LIST_HEAD(&pcp->list);
+        for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
+                INIT_LIST_HEAD(&pcp->lists[migratetype]);
 }
 
 /*
@@ -3146,6 +3244,32 @@ int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
         return 0;
 }
 
+static int __zone_pcp_update(void *data)
+{
+        struct zone *zone = data;
+        int cpu;
+        unsigned long batch = zone_batchsize(zone), flags;
+
+        for (cpu = 0; cpu < NR_CPUS; cpu++) {
+                struct per_cpu_pageset *pset;
+                struct per_cpu_pages *pcp;
+
+                pset = zone_pcp(zone, cpu);
+                pcp = &pset->pcp;
+
+                local_irq_save(flags);
+                free_pcppages_bulk(zone, pcp->count, pcp);
+                setup_pageset(pset, batch);
+                local_irq_restore(flags);
+        }
+        return 0;
+}
+
+void zone_pcp_update(struct zone *zone)
+{
+        stop_machine(__zone_pcp_update, zone, NULL);
+}
+
 static __meminit void zone_pcp_init(struct zone *zone)
 {
         int cpu;
@@ -3720,7 +3844,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
                 zone_pcp_init(zone);
                 for_each_lru(l) {
                         INIT_LIST_HEAD(&zone->lru[l].list);
-                        zone->lru[l].nr_saved_scan = 0;
+                        zone->reclaim_stat.nr_saved_scan[l] = 0;
                 }
                 zone->reclaim_stat.recent_rotated[0] = 0;
                 zone->reclaim_stat.recent_rotated[1] = 0;
@@ -4509,7 +4633,7 @@ void setup_per_zone_wmarks(void)
         calculate_totalreserve_pages();
 }
 
-/**
+/*
  * The inactive anon list should be small enough that the VM never has to
  * do too much work, but large enough that each inactive page has a chance
  * to be referenced again before it is swapped out.
@@ -4600,9 +4724,9 @@ module_init(init_per_zone_wmark_min)
  *      changes.
  */
 int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
-        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+        void __user *buffer, size_t *length, loff_t *ppos)
 {
-        proc_dointvec(table, write, file, buffer, length, ppos);
+        proc_dointvec(table, write, buffer, length, ppos);
         if (write)
                 setup_per_zone_wmarks();
         return 0;
@@ -4610,12 +4734,12 @@ int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
 
 #ifdef CONFIG_NUMA
 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
-        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+        void __user *buffer, size_t *length, loff_t *ppos)
 {
         struct zone *zone;
         int rc;
 
-        rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
+        rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
         if (rc)
                 return rc;
 
@@ -4626,12 +4750,12 @@ int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
 }
 
 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
-        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+        void __user *buffer, size_t *length, loff_t *ppos)
 {
         struct zone *zone;
         int rc;
 
-        rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
+        rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
         if (rc)
                 return rc;
 
@@ -4652,9 +4776,9 @@ int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
  * if in function of the boot time zone sizes.
  */
 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
-        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+        void __user *buffer, size_t *length, loff_t *ppos)
 {
-        proc_dointvec_minmax(table, write, file, buffer, length, ppos);
+        proc_dointvec_minmax(table, write, buffer, length, ppos);
         setup_per_zone_lowmem_reserve();
         return 0;
 }
@@ -4666,13 +4790,13 @@ int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
  */
 
 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
-        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+        void __user *buffer, size_t *length, loff_t *ppos)
 {
         struct zone *zone;
         unsigned int cpu;
         int ret;
 
-        ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
+        ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
         if (!write || (ret == -EINVAL))
                 return ret;
         for_each_populated_zone(zone) {
@@ -4732,7 +4856,14 @@ void *__init alloc_large_system_hash(const char *tablename,
                         numentries <<= (PAGE_SHIFT - scale);
 
                 /* Make sure we've got at least a 0-order allocation.. */
-                if (unlikely((numentries * bucketsize) < PAGE_SIZE))
+                if (unlikely(flags & HASH_SMALL)) {
+                        /* Makes no sense without HASH_EARLY */
+                        WARN_ON(!(flags & HASH_EARLY));
+                        if (!(numentries >> *_hash_shift)) {
+                                numentries = 1UL << *_hash_shift;
+                                BUG_ON(!numentries);
+                        }
+                } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
                         numentries = PAGE_SIZE / bucketsize;
         }
         numentries = roundup_pow_of_two(numentries);
@@ -4874,13 +5005,16 @@ int set_migratetype_isolate(struct page *page)
         struct zone *zone;
         unsigned long flags;
         int ret = -EBUSY;
+        int zone_idx;
 
         zone = page_zone(page);
+        zone_idx = zone_idx(zone);
         spin_lock_irqsave(&zone->lock, flags);
         /*
          * In future, more migrate types will be able to be isolation target.
          */
-        if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
+        if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE &&
+            zone_idx != ZONE_MOVABLE)
                 goto out;
         set_pageblock_migratetype(page, MIGRATE_ISOLATE);
         move_freepages_block(zone, page, MIGRATE_ISOLATE);
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index f22b4ebbd8dc..3d535d594826 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -116,10 +116,16 @@ static int __init_refok init_section_page_cgroup(unsigned long pfn)
                 nid = page_to_nid(pfn_to_page(pfn));
                 table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
                 VM_BUG_ON(!slab_is_available());
-                base = kmalloc_node(table_size,
+                if (node_state(nid, N_HIGH_MEMORY)) {
+                        base = kmalloc_node(table_size,
                                 GFP_KERNEL | __GFP_NOWARN, nid);
-                if (!base)
-                        base = vmalloc_node(table_size, nid);
+                        if (!base)
+                                base = vmalloc_node(table_size, nid);
+                } else {
+                        base = kmalloc(table_size, GFP_KERNEL | __GFP_NOWARN);
+                        if (!base)
+                                base = vmalloc(table_size);
+                }
         } else {
                 /*
                  * We don't have to allocate page_cgroup again, but
diff --git a/mm/pdflush.c b/mm/pdflush.c
deleted file mode 100644
index 235ac440c44e..000000000000
--- a/mm/pdflush.c
+++ /dev/null
@@ -1,269 +0,0 @@
-/*
- * mm/pdflush.c - worker threads for writing back filesystem data
- *
- * Copyright (C) 2002, Linus Torvalds.
- *
- * 09Apr2002    Andrew Morton
- *              Initial version
- * 29Feb2004    kaos@sgi.com
- *              Move worker thread creation to kthread to avoid chewing
- *              up stack space with nested calls to kernel_thread.
- */
-
-#include <linux/sched.h>
-#include <linux/list.h>
-#include <linux/signal.h>
-#include <linux/spinlock.h>
-#include <linux/gfp.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/fs.h>           /* Needed by writeback.h          */
-#include <linux/writeback.h>    /* Prototypes pdflush_operation() */
-#include <linux/kthread.h>
-#include <linux/cpuset.h>
-#include <linux/freezer.h>
-
-
-/*
- * Minimum and maximum number of pdflush instances
- */
-#define MIN_PDFLUSH_THREADS     2
-#define MAX_PDFLUSH_THREADS     8
-
-static void start_one_pdflush_thread(void);
-
-
-/*
- * The pdflush threads are worker threads for writing back dirty data.
- * Ideally, we'd like one thread per active disk spindle.  But the disk
- * topology is very hard to divine at this level.   Instead, we take
- * care in various places to prevent more than one pdflush thread from
- * performing writeback against a single filesystem.  pdflush threads
- * have the PF_FLUSHER flag set in current->flags to aid in this.
- */
-
-/*
- * All the pdflush threads.  Protected by pdflush_lock
- */
-static LIST_HEAD(pdflush_list);
-static DEFINE_SPINLOCK(pdflush_lock);
-
-/*
- * The count of currently-running pdflush threads.  Protected
- * by pdflush_lock.
- *
- * Readable by sysctl, but not writable.  Published to userspace at
- * /proc/sys/vm/nr_pdflush_threads.
- */
-int nr_pdflush_threads = 0;
-
-/*
- * The time at which the pdflush thread pool last went empty
- */
-static unsigned long last_empty_jifs;
-
-/*
- * The pdflush thread.
- *
- * Thread pool management algorithm:
- * 
- * - The minimum and maximum number of pdflush instances are bound
- *   by MIN_PDFLUSH_THREADS and MAX_PDFLUSH_THREADS.
- * 
- * - If there have been no idle pdflush instances for 1 second, create
- *   a new one.
- * 
- * - If the least-recently-went-to-sleep pdflush thread has been asleep
- *   for more than one second, terminate a thread.
- */
-
-/*
- * A structure for passing work to a pdflush thread.  Also for passing
- * state information between pdflush threads.  Protected by pdflush_lock.
- */
-struct pdflush_work {
-        struct task_struct *who;        /* The thread */
-        void (*fn)(unsigned long);      /* A callback function */
-        unsigned long arg0;             /* An argument to the callback */
-        struct list_head list;          /* On pdflush_list, when idle */
-        unsigned long when_i_went_to_sleep;
-};
-
-static int __pdflush(struct pdflush_work *my_work)
-{
-        current->flags |= PF_FLUSHER | PF_SWAPWRITE;
-        set_freezable();
-        my_work->fn = NULL;
-        my_work->who = current;
-        INIT_LIST_HEAD(&my_work->list);
-
-        spin_lock_irq(&pdflush_lock);
-        for ( ; ; ) {
-                struct pdflush_work *pdf;
-
-                set_current_state(TASK_INTERRUPTIBLE);
-                list_move(&my_work->list, &pdflush_list);
-                my_work->when_i_went_to_sleep = jiffies;
-                spin_unlock_irq(&pdflush_lock);
-                schedule();
-                try_to_freeze();
-                spin_lock_irq(&pdflush_lock);
-                if (!list_empty(&my_work->list)) {
-                        /*
-                         * Someone woke us up, but without removing our control
-                         * structure from the global list.  swsusp will do this
-                         * in try_to_freeze()->refrigerator().  Handle it.
-                         */
-                        my_work->fn = NULL;
-                        continue;
-                }
-                if (my_work->fn == NULL) {
-                        printk("pdflush: bogus wakeup\n");
-                        continue;
-                }
-                spin_unlock_irq(&pdflush_lock);
-
-                (*my_work->fn)(my_work->arg0);
-
-                spin_lock_irq(&pdflush_lock);
-
-                /*
-                 * Thread creation: For how long have there been zero
-                 * available threads?
-                 *
-                 * To throttle creation, we reset last_empty_jifs.
-                 */
-                if (time_after(jiffies, last_empty_jifs + 1 * HZ)) {
-                        if (list_empty(&pdflush_list)) {
-                                if (nr_pdflush_threads < MAX_PDFLUSH_THREADS) {
-                                        last_empty_jifs = jiffies;
-                                        nr_pdflush_threads++;
-                                        spin_unlock_irq(&pdflush_lock);
-                                        start_one_pdflush_thread();
-                                        spin_lock_irq(&pdflush_lock);
-                                }
-                        }
-                }
-
-                my_work->fn = NULL;
-
-                /*
-                 * Thread destruction: For how long has the sleepiest
-                 * thread slept?
-                 */
-                if (list_empty(&pdflush_list))
-                        continue;
-                if (nr_pdflush_threads <= MIN_PDFLUSH_THREADS)
-                        continue;
-                pdf = list_entry(pdflush_list.prev, struct pdflush_work, list);
-                if (time_after(jiffies, pdf->when_i_went_to_sleep + 1 * HZ)) {
-                        /* Limit exit rate */
-                        pdf->when_i_went_to_sleep = jiffies;
-                        break;                                  /* exeunt */
-                }
-        }
-        nr_pdflush_threads--;
-        spin_unlock_irq(&pdflush_lock);
-        return 0;
-}
-
-/*
- * Of course, my_work wants to be just a local in __pdflush().  It is
- * separated out in this manner to hopefully prevent the compiler from
- * performing unfortunate optimisations against the auto variables.  Because
- * these are visible to other tasks and CPUs.  (No problem has actually
- * been observed.  This is just paranoia).
- */
-static int pdflush(void *dummy)
-{
-        struct pdflush_work my_work;
-        cpumask_var_t cpus_allowed;
-
-        /*
-         * Since the caller doesn't even check kthread_run() worked, let's not
-         * freak out too much if this fails.
-         */
-        if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
-                printk(KERN_WARNING "pdflush failed to allocate cpumask\n");
-                return 0;
-        }
-
-        /*
-         * pdflush can spend a lot of time doing encryption via dm-crypt.  We
-         * don't want to do that at keventd's priority.
-         */
-        set_user_nice(current, 0);
-
-        /*
-         * Some configs put our parent kthread in a limited cpuset,
-         * which kthread() overrides, forcing cpus_allowed == cpu_all_mask.
-         * Our needs are more modest - cut back to our cpusets cpus_allowed.
-         * This is needed as pdflush's are dynamically created and destroyed.
-         * The boottime pdflush's are easily placed w/o these 2 lines.
-         */
-        cpuset_cpus_allowed(current, cpus_allowed);
-        set_cpus_allowed_ptr(current, cpus_allowed);
-        free_cpumask_var(cpus_allowed);
-
-        return __pdflush(&my_work);
-}
-
-/*
- * Attempt to wake up a pdflush thread, and get it to do some work for you.
- * Returns zero if it indeed managed to find a worker thread, and passed your
- * payload to it.
- */
-int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0)
-{
-        unsigned long flags;
-        int ret = 0;
-
-        BUG_ON(fn == NULL);     /* Hard to diagnose if it's deferred */
-
-        spin_lock_irqsave(&pdflush_lock, flags);
-        if (list_empty(&pdflush_list)) {
-                ret = -1;
-        } else {
-                struct pdflush_work *pdf;
-
-                pdf = list_entry(pdflush_list.next, struct pdflush_work, list);
-                list_del_init(&pdf->list);
-                if (list_empty(&pdflush_list))
-                        last_empty_jifs = jiffies;
-                pdf->fn = fn;
-                pdf->arg0 = arg0;
-                wake_up_process(pdf->who);
-        }
-        spin_unlock_irqrestore(&pdflush_lock, flags);
-
-        return ret;
-}
-
-static void start_one_pdflush_thread(void)
-{
-        struct task_struct *k;
-
-        k = kthread_run(pdflush, NULL, "pdflush");
-        if (unlikely(IS_ERR(k))) {
-                spin_lock_irq(&pdflush_lock);
-                nr_pdflush_threads--;
-                spin_unlock_irq(&pdflush_lock);
-        }
-}
-
-static int __init pdflush_init(void)
-{
-        int i;
-
-        /*
-         * Pre-set nr_pdflush_threads...  If we fail to create,
-         * the count will be decremented.
-         */
-        nr_pdflush_threads = MIN_PDFLUSH_THREADS;
-
-        for (i = 0; i < MIN_PDFLUSH_THREADS; i++)
-                start_one_pdflush_thread();
-        return 0;
-}
-
-module_init(pdflush_init);
diff --git a/mm/percpu.c b/mm/percpu.c
index 3311c8919f37..6af78c1ee704 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -8,12 +8,13 @@
  *
  * This is percpu allocator which can handle both static and dynamic
  * areas.  Percpu areas are allocated in chunks in vmalloc area.  Each
- * chunk is consisted of nr_cpu_ids units and the first chunk is used
- * for static percpu variables in the kernel image (special boot time
- * alloc/init handling necessary as these areas need to be brought up
- * before allocation services are running).  Unit grows as necessary
- * and all units grow or shrink in unison.  When a chunk is filled up,
- * another chunk is allocated.  ie. in vmalloc area
+ * chunk is consisted of boot-time determined number of units and the
+ * first chunk is used for static percpu variables in the kernel image
+ * (special boot time alloc/init handling necessary as these areas
+ * need to be brought up before allocation services are running).
+ * Unit grows as necessary and all units grow or shrink in unison.
+ * When a chunk is filled up, another chunk is allocated.  ie. in
+ * vmalloc area
  *
  *  c0                           c1                         c2
  *  -------------------          -------------------        ------------
@@ -22,11 +23,13 @@
  *
  * Allocation is done in offset-size areas of single unit space.  Ie,
  * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0,
- * c1:u1, c1:u2 and c1:u3.  Percpu access can be done by configuring
- * percpu base registers pcpu_unit_size apart.
+ * c1:u1, c1:u2 and c1:u3.  On UMA, units corresponds directly to
+ * cpus.  On NUMA, the mapping can be non-linear and even sparse.
+ * Percpu access can be done by configuring percpu base registers
+ * according to cpu to unit mapping and pcpu_unit_size.
  *
- * There are usually many small percpu allocations many of them as
- * small as 4 bytes.  The allocator organizes chunks into lists
+ * There are usually many small percpu allocations many of them being
+ * as small as 4 bytes.  The allocator organizes chunks into lists
  * according to free size and tries to allocate from the fullest one.
  * Each chunk keeps the maximum contiguous area size hint which is
  * guaranteed to be eqaul to or larger than the maximum contiguous
@@ -43,7 +46,7 @@
  *
  * To use this allocator, arch code should do the followings.
  *
- * - define CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
+ * - drop CONFIG_HAVE_LEGACY_PER_CPU_AREA
  *
  * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate
  *   regular address to percpu pointer and back if they need to be
@@ -55,7 +58,9 @@
 
 #include <linux/bitmap.h>
 #include <linux/bootmem.h>
+#include <linux/err.h>
 #include <linux/list.h>
+#include <linux/log2.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -89,25 +94,38 @@ struct pcpu_chunk {
         struct list_head        list;           /* linked to pcpu_slot lists */
         int                     free_size;      /* free bytes in the chunk */
         int                     contig_hint;    /* max contiguous size hint */
-        struct vm_struct        *vm;            /* mapped vmalloc region */
+        void                    *base_addr;     /* base address of this chunk */
         int                     map_used;       /* # of map entries used */
         int                     map_alloc;      /* # of map entries allocated */
         int                     *map;           /* allocation map */
+        struct vm_struct        **vms;          /* mapped vmalloc regions */
         bool                    immutable;      /* no [de]population allowed */
-        struct page             **page;         /* points to page array */
-        struct page             *page_ar[];     /* #cpus * UNIT_PAGES */
+        unsigned long           populated[];    /* populated bitmap */
 };
 
 static int pcpu_unit_pages __read_mostly;
 static int pcpu_unit_size __read_mostly;
-static int pcpu_chunk_size __read_mostly;
+static int pcpu_nr_units __read_mostly;
+static int pcpu_atom_size __read_mostly;
 static int pcpu_nr_slots __read_mostly;
 static size_t pcpu_chunk_struct_size __read_mostly;
 
+/* cpus with the lowest and highest unit numbers */
+static unsigned int pcpu_first_unit_cpu __read_mostly;
+static unsigned int pcpu_last_unit_cpu __read_mostly;
+
 /* the address of the first chunk which starts with the kernel static area */
 void *pcpu_base_addr __read_mostly;
 EXPORT_SYMBOL_GPL(pcpu_base_addr);
 
+static const int *pcpu_unit_map __read_mostly;          /* cpu -> unit */
+const unsigned long *pcpu_unit_offsets __read_mostly;   /* cpu -> unit offset */
+
+/* group information, used for vm allocation */
+static int pcpu_nr_groups __read_mostly;
+static const unsigned long *pcpu_group_offsets __read_mostly;
+static const size_t *pcpu_group_sizes __read_mostly;
+
 /*
  * The first chunk which always exists.  Note that unlike other
  * chunks, this one can be allocated and mapped in several different
@@ -129,9 +147,9 @@ static int pcpu_reserved_chunk_limit;
  * Synchronization rules.
  *
  * There are two locks - pcpu_alloc_mutex and pcpu_lock.  The former
- * protects allocation/reclaim paths, chunks and chunk->page arrays.
- * The latter is a spinlock and protects the index data structures -
- * chunk slots, chunks and area maps in chunks.
+ * protects allocation/reclaim paths, chunks, populated bitmap and
+ * vmalloc mapping.  The latter is a spinlock and protects the index
+ * data structures - chunk slots, chunks and area maps in chunks.
  *
  * During allocation, pcpu_alloc_mutex is kept locked all the time and
  * pcpu_lock is grabbed and released as necessary.  All actual memory
@@ -178,31 +196,23 @@ static int pcpu_chunk_slot(const struct pcpu_chunk *chunk)
 
 static int pcpu_page_idx(unsigned int cpu, int page_idx)
 {
-        return cpu * pcpu_unit_pages + page_idx;
-}
-
-static struct page **pcpu_chunk_pagep(struct pcpu_chunk *chunk,
-                                      unsigned int cpu, int page_idx)
-{
-        return &chunk->page[pcpu_page_idx(cpu, page_idx)];
+        return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx;
 }
 
 static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk,
                                      unsigned int cpu, int page_idx)
 {
-        return (unsigned long)chunk->vm->addr +
-                (pcpu_page_idx(cpu, page_idx) << PAGE_SHIFT);
+        return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] +
+                (page_idx << PAGE_SHIFT);
 }
 
-static bool pcpu_chunk_page_occupied(struct pcpu_chunk *chunk,
-                                     int page_idx)
+static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk,
+                                    unsigned int cpu, int page_idx)
 {
-        /*
-         * Any possible cpu id can be used here, so there's no need to
-         * worry about preemption or cpu hotplug.
-         */
-        return *pcpu_chunk_pagep(chunk, raw_smp_processor_id(),
-                                 page_idx) != NULL;
+        /* must not be used on pre-mapped chunk */
+        WARN_ON(chunk->immutable);
+
+        return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx));
 }
 
 /* set the pointer to a chunk in a page struct */
@@ -217,6 +227,34 @@ static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page)
         return (struct pcpu_chunk *)page->index;
 }
 
+static void pcpu_next_unpop(struct pcpu_chunk *chunk, int *rs, int *re, int end)
+{
+        *rs = find_next_zero_bit(chunk->populated, end, *rs);
+        *re = find_next_bit(chunk->populated, end, *rs + 1);
+}
+
+static void pcpu_next_pop(struct pcpu_chunk *chunk, int *rs, int *re, int end)
+{
+        *rs = find_next_bit(chunk->populated, end, *rs);
+        *re = find_next_zero_bit(chunk->populated, end, *rs + 1);
+}
+
+/*
+ * (Un)populated page region iterators.  Iterate over (un)populated
+ * page regions betwen @start and @end in @chunk.  @rs and @re should
+ * be integer variables and will be set to start and end page index of
+ * the current region.
+ */
+#define pcpu_for_each_unpop_region(chunk, rs, re, start, end)               \
+        for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \
+             (rs) < (re);                                                   \
+             (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end)))
+
+#define pcpu_for_each_pop_region(chunk, rs, re, start, end)                 \
+        for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end));   \
+             (rs) < (re);                                                   \
+             (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end)))
+
 /**
  * pcpu_mem_alloc - allocate memory
  * @size: bytes to allocate
@@ -292,10 +330,10 @@ static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot)
  */
 static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
 {
-        void *first_start = pcpu_first_chunk->vm->addr;
+        void *first_start = pcpu_first_chunk->base_addr;
 
         /* is it in the first chunk? */
-        if (addr >= first_start && addr < first_start + pcpu_chunk_size) {
+        if (addr >= first_start && addr < first_start + pcpu_unit_size) {
                 /* is it in the reserved area? */
                 if (addr < first_start + pcpu_reserved_chunk_limit)
                         return pcpu_reserved_chunk;
@@ -309,7 +347,7 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
          * space.  Note that any possible cpu id can be used here, so
          * there's no need to worry about preemption or cpu hotplug.
          */
-        addr += raw_smp_processor_id() * pcpu_unit_size;
+        addr += pcpu_unit_offsets[raw_smp_processor_id()];
         return pcpu_get_page_chunk(vmalloc_to_page(addr));
 }
 
@@ -558,125 +596,327 @@ static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme)
 }
 
 /**
- * pcpu_unmap - unmap pages out of a pcpu_chunk
+ * pcpu_get_pages_and_bitmap - get temp pages array and bitmap
  * @chunk: chunk of interest
- * @page_start: page index of the first page to unmap
- * @page_end: page index of the last page to unmap + 1
- * @flush_tlb: whether to flush tlb or not
+ * @bitmapp: output parameter for bitmap
+ * @may_alloc: may allocate the array
  *
- * For each cpu, unmap pages [@page_start,@page_end) out of @chunk.
- * If @flush is true, vcache is flushed before unmapping and tlb
- * after.
+ * Returns pointer to array of pointers to struct page and bitmap,
+ * both of which can be indexed with pcpu_page_idx().  The returned
+ * array is cleared to zero and *@bitmapp is copied from
+ * @chunk->populated.  Note that there is only one array and bitmap
+ * and access exclusion is the caller's responsibility.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex and does GFP_KERNEL allocation if @may_alloc.
+ * Otherwise, don't care.
+ *
+ * RETURNS:
+ * Pointer to temp pages array on success, NULL on failure.
  */
-static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end,
-                       bool flush_tlb)
+static struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk,
+                                               unsigned long **bitmapp,
+                                               bool may_alloc)
 {
-        unsigned int last = nr_cpu_ids - 1;
-        unsigned int cpu;
+        static struct page **pages;
+        static unsigned long *bitmap;
+        size_t pages_size = pcpu_nr_units * pcpu_unit_pages * sizeof(pages[0]);
+        size_t bitmap_size = BITS_TO_LONGS(pcpu_unit_pages) *
+                             sizeof(unsigned long);
+
+        if (!pages || !bitmap) {
+                if (may_alloc && !pages)
+                        pages = pcpu_mem_alloc(pages_size);
+                if (may_alloc && !bitmap)
+                        bitmap = pcpu_mem_alloc(bitmap_size);
+                if (!pages || !bitmap)
+                        return NULL;
+        }
 
-        /* unmap must not be done on immutable chunk */
-        WARN_ON(chunk->immutable);
+        memset(pages, 0, pages_size);
+        bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages);
 
-        /*
-         * Each flushing trial can be very expensive, issue flush on
-         * the whole region at once rather than doing it for each cpu.
-         * This could be an overkill but is more scalable.
-         */
-        flush_cache_vunmap(pcpu_chunk_addr(chunk, 0, page_start),
-                           pcpu_chunk_addr(chunk, last, page_end));
+        *bitmapp = bitmap;
+        return pages;
+}
 
-        for_each_possible_cpu(cpu)
-                unmap_kernel_range_noflush(
-                                pcpu_chunk_addr(chunk, cpu, page_start),
-                                (page_end - page_start) << PAGE_SHIFT);
-
-        /* ditto as flush_cache_vunmap() */
-        if (flush_tlb)
-                flush_tlb_kernel_range(pcpu_chunk_addr(chunk, 0, page_start),
-                                       pcpu_chunk_addr(chunk, last, page_end));
+/**
+ * pcpu_free_pages - free pages which were allocated for @chunk
+ * @chunk: chunk pages were allocated for
+ * @pages: array of pages to be freed, indexed by pcpu_page_idx()
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to be freed
+ * @page_end: page index of the last page to be freed + 1
+ *
+ * Free pages [@page_start and @page_end) in @pages for all units.
+ * The pages were allocated for @chunk.
+ */
+static void pcpu_free_pages(struct pcpu_chunk *chunk,
+                            struct page **pages, unsigned long *populated,
+                            int page_start, int page_end)
+{
+        unsigned int cpu;
+        int i;
+
+        for_each_possible_cpu(cpu) {
+                for (i = page_start; i < page_end; i++) {
+                        struct page *page = pages[pcpu_page_idx(cpu, i)];
+
+                        if (page)
+                                __free_page(page);
+                }
+        }
 }
 
 /**
- * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk
- * @chunk: chunk to depopulate
- * @off: offset to the area to depopulate
- * @size: size of the area to depopulate in bytes
- * @flush: whether to flush cache and tlb or not
- *
- * For each cpu, depopulate and unmap pages [@page_start,@page_end)
- * from @chunk.  If @flush is true, vcache is flushed before unmapping
- * and tlb after.
- *
- * CONTEXT:
- * pcpu_alloc_mutex.
+ * pcpu_alloc_pages - allocates pages for @chunk
+ * @chunk: target chunk
+ * @pages: array to put the allocated pages into, indexed by pcpu_page_idx()
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to be allocated
+ * @page_end: page index of the last page to be allocated + 1
+ *
+ * Allocate pages [@page_start,@page_end) into @pages for all units.
+ * The allocation is for @chunk.  Percpu core doesn't care about the
+ * content of @pages and will pass it verbatim to pcpu_map_pages().
  */
-static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size,
-                                  bool flush)
+static int pcpu_alloc_pages(struct pcpu_chunk *chunk,
+                            struct page **pages, unsigned long *populated,
+                            int page_start, int page_end)
 {
-        int page_start = PFN_DOWN(off);
-        int page_end = PFN_UP(off + size);
-        int unmap_start = -1;
-        int uninitialized_var(unmap_end);
+        const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
         unsigned int cpu;
         int i;
 
-        for (i = page_start; i < page_end; i++) {
-                for_each_possible_cpu(cpu) {
-                        struct page **pagep = pcpu_chunk_pagep(chunk, cpu, i);
+        for_each_possible_cpu(cpu) {
+                for (i = page_start; i < page_end; i++) {
+                        struct page **pagep = &pages[pcpu_page_idx(cpu, i)];
+
+                        *pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0);
+                        if (!*pagep) {
+                                pcpu_free_pages(chunk, pages, populated,
+                                                page_start, page_end);
+                                return -ENOMEM;
+                        }
+                }
+        }
+        return 0;
+}
 
-                        if (!*pagep)
-                                continue;
+/**
+ * pcpu_pre_unmap_flush - flush cache prior to unmapping
+ * @chunk: chunk the regions to be flushed belongs to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages in [@page_start,@page_end) of @chunk are about to be
+ * unmapped.  Flush cache.  As each flushing trial can be very
+ * expensive, issue flush on the whole region at once rather than
+ * doing it for each cpu.  This could be an overkill but is more
+ * scalable.
+ */
+static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk,
+                                 int page_start, int page_end)
+{
+        flush_cache_vunmap(
+                pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+                pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
+}
 
-                        __free_page(*pagep);
+static void __pcpu_unmap_pages(unsigned long addr, int nr_pages)
+{
+        unmap_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT);
+}
 
-                        /*
-                         * If it's partial depopulation, it might get
-                         * populated or depopulated again.  Mark the
-                         * page gone.
-                         */
-                        *pagep = NULL;
+/**
+ * pcpu_unmap_pages - unmap pages out of a pcpu_chunk
+ * @chunk: chunk of interest
+ * @pages: pages array which can be used to pass information to free
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to unmap
+ * @page_end: page index of the last page to unmap + 1
+ *
+ * For each cpu, unmap pages [@page_start,@page_end) out of @chunk.
+ * Corresponding elements in @pages were cleared by the caller and can
+ * be used to carry information to pcpu_free_pages() which will be
+ * called after all unmaps are finished.  The caller should call
+ * proper pre/post flush functions.
+ */
+static void pcpu_unmap_pages(struct pcpu_chunk *chunk,
+                             struct page **pages, unsigned long *populated,
+                             int page_start, int page_end)
+{
+        unsigned int cpu;
+        int i;
+
+        for_each_possible_cpu(cpu) {
+                for (i = page_start; i < page_end; i++) {
+                        struct page *page;
 
-                        unmap_start = unmap_start < 0 ? i : unmap_start;
-                        unmap_end = i + 1;
+                        page = pcpu_chunk_page(chunk, cpu, i);
+                        WARN_ON(!page);
+                        pages[pcpu_page_idx(cpu, i)] = page;
                 }
+                __pcpu_unmap_pages(pcpu_chunk_addr(chunk, cpu, page_start),
+                                   page_end - page_start);
         }
 
-        if (unmap_start >= 0)
-                pcpu_unmap(chunk, unmap_start, unmap_end, flush);
+        for (i = page_start; i < page_end; i++)
+                __clear_bit(i, populated);
 }
 
 /**
- * pcpu_map - map pages into a pcpu_chunk
+ * pcpu_post_unmap_tlb_flush - flush TLB after unmapping
+ * @chunk: pcpu_chunk the regions to be flushed belong to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages [@page_start,@page_end) of @chunk have been unmapped.  Flush
+ * TLB for the regions.  This can be skipped if the area is to be
+ * returned to vmalloc as vmalloc will handle TLB flushing lazily.
+ *
+ * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once
+ * for the whole region.
+ */
+static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk,
+                                      int page_start, int page_end)
+{
+        flush_tlb_kernel_range(
+                pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+                pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
+}
+
+static int __pcpu_map_pages(unsigned long addr, struct page **pages,
+                            int nr_pages)
+{
+        return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT,
+                                        PAGE_KERNEL, pages);
+}
+
+/**
+ * pcpu_map_pages - map pages into a pcpu_chunk
  * @chunk: chunk of interest
+ * @pages: pages array containing pages to be mapped
+ * @populated: populated bitmap
  * @page_start: page index of the first page to map
  * @page_end: page index of the last page to map + 1
  *
- * For each cpu, map pages [@page_start,@page_end) into @chunk.
- * vcache is flushed afterwards.
+ * For each cpu, map pages [@page_start,@page_end) into @chunk.  The
+ * caller is responsible for calling pcpu_post_map_flush() after all
+ * mappings are complete.
+ *
+ * This function is responsible for setting corresponding bits in
+ * @chunk->populated bitmap and whatever is necessary for reverse
+ * lookup (addr -> chunk).
  */
-static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)
+static int pcpu_map_pages(struct pcpu_chunk *chunk,
+                          struct page **pages, unsigned long *populated,
+                          int page_start, int page_end)
 {
-        unsigned int last = nr_cpu_ids - 1;
-        unsigned int cpu;
-        int err;
-
-        /* map must not be done on immutable chunk */
-        WARN_ON(chunk->immutable);
+        unsigned int cpu, tcpu;
+        int i, err;
 
         for_each_possible_cpu(cpu) {
-                err = map_kernel_range_noflush(
-                                pcpu_chunk_addr(chunk, cpu, page_start),
-                                (page_end - page_start) << PAGE_SHIFT,
-                                PAGE_KERNEL,
-                                pcpu_chunk_pagep(chunk, cpu, page_start));
+                err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start),
+                                       &pages[pcpu_page_idx(cpu, page_start)],
+                                       page_end - page_start);
                 if (err < 0)
-                        return err;
+                        goto err;
+        }
+
+        /* mapping successful, link chunk and mark populated */
+        for (i = page_start; i < page_end; i++) {
+                for_each_possible_cpu(cpu)
+                        pcpu_set_page_chunk(pages[pcpu_page_idx(cpu, i)],
+                                            chunk);
+                __set_bit(i, populated);
         }
 
-        /* flush at once, please read comments in pcpu_unmap() */
-        flush_cache_vmap(pcpu_chunk_addr(chunk, 0, page_start),
-                         pcpu_chunk_addr(chunk, last, page_end));
         return 0;
+
+err:
+        for_each_possible_cpu(tcpu) {
+                if (tcpu == cpu)
+                        break;
+                __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start),
+                                   page_end - page_start);
+        }
+        return err;
+}
+
+/**
+ * pcpu_post_map_flush - flush cache after mapping
+ * @chunk: pcpu_chunk the regions to be flushed belong to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages [@page_start,@page_end) of @chunk have been mapped.  Flush
+ * cache.
+ *
+ * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once
+ * for the whole region.
+ */
+static void pcpu_post_map_flush(struct pcpu_chunk *chunk,
+                                int page_start, int page_end)
+{
+        flush_cache_vmap(
+                pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+                pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
+}
+
+/**
+ * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk
+ * @chunk: chunk to depopulate
+ * @off: offset to the area to depopulate
+ * @size: size of the area to depopulate in bytes
+ * @flush: whether to flush cache and tlb or not
+ *
+ * For each cpu, depopulate and unmap pages [@page_start,@page_end)
+ * from @chunk.  If @flush is true, vcache is flushed before unmapping
+ * and tlb after.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex.
+ */
+static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size)
+{
+        int page_start = PFN_DOWN(off);
+        int page_end = PFN_UP(off + size);
+        struct page **pages;
+        unsigned long *populated;
+        int rs, re;
+
+        /* quick path, check whether it's empty already */
+        pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+                if (rs == page_start && re == page_end)
+                        return;
+                break;
+        }
+
+        /* immutable chunks can't be depopulated */
+        WARN_ON(chunk->immutable);
+
+        /*
+         * If control reaches here, there must have been at least one
+         * successful population attempt so the temp pages array must
+         * be available now.
+         */
+        pages = pcpu_get_pages_and_bitmap(chunk, &populated, false);
+        BUG_ON(!pages);
+
+        /* unmap and free */
+        pcpu_pre_unmap_flush(chunk, page_start, page_end);
+
+        pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
+                pcpu_unmap_pages(chunk, pages, populated, rs, re);
+
+        /* no need to flush tlb, vmalloc will handle it lazily */
+
+        pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
+                pcpu_free_pages(chunk, pages, populated, rs, re);
+
+        /* commit new bitmap */
+        bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
 }
 
 /**
@@ -693,58 +933,68 @@ static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)
  */
 static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
 {
-        const gfp_t alloc_mask = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
         int page_start = PFN_DOWN(off);
         int page_end = PFN_UP(off + size);
-        int map_start = -1;
-        int uninitialized_var(map_end);
+        int free_end = page_start, unmap_end = page_start;
+        struct page **pages;
+        unsigned long *populated;
         unsigned int cpu;
-        int i;
+        int rs, re, rc;
 
-        for (i = page_start; i < page_end; i++) {
-                if (pcpu_chunk_page_occupied(chunk, i)) {
-                        if (map_start >= 0) {
-                                if (pcpu_map(chunk, map_start, map_end))
-                                        goto err;
-                                map_start = -1;
-                        }
-                        continue;
-                }
+        /* quick path, check whether all pages are already there */
+        pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) {
+                if (rs == page_start && re == page_end)
+                        goto clear;
+                break;
+        }
 
-                map_start = map_start < 0 ? i : map_start;
-                map_end = i + 1;
+        /* need to allocate and map pages, this chunk can't be immutable */
+        WARN_ON(chunk->immutable);
 
-                for_each_possible_cpu(cpu) {
-                        struct page **pagep = pcpu_chunk_pagep(chunk, cpu, i);
+        pages = pcpu_get_pages_and_bitmap(chunk, &populated, true);
+        if (!pages)
+                return -ENOMEM;
 
-                        *pagep = alloc_pages_node(cpu_to_node(cpu),
-                                                  alloc_mask, 0);
-                        if (!*pagep)
-                                goto err;
-                        pcpu_set_page_chunk(*pagep, chunk);
-                }
+        /* alloc and map */
+        pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+                rc = pcpu_alloc_pages(chunk, pages, populated, rs, re);
+                if (rc)
+                        goto err_free;
+                free_end = re;
         }
 
-        if (map_start >= 0 && pcpu_map(chunk, map_start, map_end))
-                goto err;
+        pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+                rc = pcpu_map_pages(chunk, pages, populated, rs, re);
+                if (rc)
+                        goto err_unmap;
+                unmap_end = re;
+        }
+        pcpu_post_map_flush(chunk, page_start, page_end);
 
+        /* commit new bitmap */
+        bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
+clear:
         for_each_possible_cpu(cpu)
-                memset(chunk->vm->addr + cpu * pcpu_unit_size + off, 0,
-                       size);
-
+                memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
         return 0;
-err:
-        /* likely under heavy memory pressure, give memory back */
-        pcpu_depopulate_chunk(chunk, off, size, true);
-        return -ENOMEM;
+
+err_unmap:
+        pcpu_pre_unmap_flush(chunk, page_start, unmap_end);
+        pcpu_for_each_unpop_region(chunk, rs, re, page_start, unmap_end)
+                pcpu_unmap_pages(chunk, pages, populated, rs, re);
+        pcpu_post_unmap_tlb_flush(chunk, page_start, unmap_end);
+err_free:
+        pcpu_for_each_unpop_region(chunk, rs, re, page_start, free_end)
+                pcpu_free_pages(chunk, pages, populated, rs, re);
+        return rc;
 }
 
 static void free_pcpu_chunk(struct pcpu_chunk *chunk)
 {
         if (!chunk)
                 return;
-        if (chunk->vm)
-                free_vm_area(chunk->vm);
+        if (chunk->vms)
+                pcpu_free_vm_areas(chunk->vms, pcpu_nr_groups);
         pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
         kfree(chunk);
 }
@@ -760,10 +1010,11 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
         chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
         chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
         chunk->map[chunk->map_used++] = pcpu_unit_size;
-        chunk->page = chunk->page_ar;
 
-        chunk->vm = get_vm_area(pcpu_chunk_size, VM_ALLOC);
-        if (!chunk->vm) {
+        chunk->vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
+                                       pcpu_nr_groups, pcpu_atom_size,
+                                       GFP_KERNEL);
+        if (!chunk->vms) {
                 free_pcpu_chunk(chunk);
                 return NULL;
         }
@@ -771,6 +1022,7 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
         INIT_LIST_HEAD(&chunk->list);
         chunk->free_size = pcpu_unit_size;
         chunk->contig_hint = pcpu_unit_size;
+        chunk->base_addr = chunk->vms[0]->addr - pcpu_group_offsets[0];
 
         return chunk;
 }
@@ -791,7 +1043,9 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
  */
 static void *pcpu_alloc(size_t size, size_t align, bool reserved)
 {
+        static int warn_limit = 10;
         struct pcpu_chunk *chunk;
+        const char *err;
         int slot, off;
 
         if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
@@ -807,11 +1061,14 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
         if (reserved && pcpu_reserved_chunk) {
                 chunk = pcpu_reserved_chunk;
                 if (size > chunk->contig_hint ||
-                    pcpu_extend_area_map(chunk) < 0)
+                    pcpu_extend_area_map(chunk) < 0) {
+                        err = "failed to extend area map of reserved chunk";
                         goto fail_unlock;
+                }
                 off = pcpu_alloc_area(chunk, size, align);
                 if (off >= 0)
                         goto area_found;
+                err = "alloc from reserved chunk failed";
                 goto fail_unlock;
         }
 
@@ -828,6 +1085,7 @@ restart:
                         case 1:
                                 goto restart;   /* pcpu_lock dropped, restart */
                         default:
+                                err = "failed to extend area map";
                                 goto fail_unlock;
                         }
 
@@ -841,8 +1099,10 @@ restart:
         spin_unlock_irq(&pcpu_lock);
 
         chunk = alloc_pcpu_chunk();
-        if (!chunk)
+        if (!chunk) {
+                err = "failed to allocate new chunk";
                 goto fail_unlock_mutex;
+        }
 
         spin_lock_irq(&pcpu_lock);
         pcpu_chunk_relocate(chunk, -1);
@@ -855,17 +1115,26 @@ area_found:
         if (pcpu_populate_chunk(chunk, off, size)) {
                 spin_lock_irq(&pcpu_lock);
                 pcpu_free_area(chunk, off);
+                err = "failed to populate";
                 goto fail_unlock;
         }
 
         mutex_unlock(&pcpu_alloc_mutex);
 
-        return __addr_to_pcpu_ptr(chunk->vm->addr + off);
+        /* return address relative to base address */
+        return __addr_to_pcpu_ptr(chunk->base_addr + off);
 
 fail_unlock:
         spin_unlock_irq(&pcpu_lock);
 fail_unlock_mutex:
         mutex_unlock(&pcpu_alloc_mutex);
+        if (warn_limit) {
+                pr_warning("PERCPU: allocation failed, size=%zu align=%zu, "
+                           "%s\n", size, align, err);
+                dump_stack();
+                if (!--warn_limit)
+                        pr_info("PERCPU: limit reached, disable warning\n");
+        }
         return NULL;
 }
 
@@ -938,12 +1207,13 @@ static void pcpu_reclaim(struct work_struct *work)
         }
 
         spin_unlock_irq(&pcpu_lock);
-        mutex_unlock(&pcpu_alloc_mutex);
 
         list_for_each_entry_safe(chunk, next, &todo, list) {
-                pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false);
+                pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size);
                 free_pcpu_chunk(chunk);
         }
+
+        mutex_unlock(&pcpu_alloc_mutex);
 }
 
 /**
@@ -968,7 +1238,7 @@ void free_percpu(void *ptr)
         spin_lock_irqsave(&pcpu_lock, flags);
 
         chunk = pcpu_chunk_addr_search(addr);
-        off = addr - chunk->vm->addr;
+        off = addr - chunk->base_addr;
 
         pcpu_free_area(chunk, off);
 
@@ -987,30 +1257,299 @@ void free_percpu(void *ptr)
 }
 EXPORT_SYMBOL_GPL(free_percpu);
 
+static inline size_t pcpu_calc_fc_sizes(size_t static_size,
+                                        size_t reserved_size,
+                                        ssize_t *dyn_sizep)
+{
+        size_t size_sum;
+
+        size_sum = PFN_ALIGN(static_size + reserved_size +
+                             (*dyn_sizep >= 0 ? *dyn_sizep : 0));
+        if (*dyn_sizep != 0)
+                *dyn_sizep = size_sum - static_size - reserved_size;
+
+        return size_sum;
+}
+
 /**
- * pcpu_setup_first_chunk - initialize the first percpu chunk
- * @get_page_fn: callback to fetch page pointer
- * @static_size: the size of static percpu area in bytes
+ * pcpu_alloc_alloc_info - allocate percpu allocation info
+ * @nr_groups: the number of groups
+ * @nr_units: the number of units
+ *
+ * Allocate ai which is large enough for @nr_groups groups containing
+ * @nr_units units.  The returned ai's groups[0].cpu_map points to the
+ * cpu_map array which is long enough for @nr_units and filled with
+ * NR_CPUS.  It's the caller's responsibility to initialize cpu_map
+ * pointer of other groups.
+ *
+ * RETURNS:
+ * Pointer to the allocated pcpu_alloc_info on success, NULL on
+ * failure.
+ */
+struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
+                                                      int nr_units)
+{
+        struct pcpu_alloc_info *ai;
+        size_t base_size, ai_size;
+        void *ptr;
+        int unit;
+
+        base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]),
+                          __alignof__(ai->groups[0].cpu_map[0]));
+        ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]);
+
+        ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size));
+        if (!ptr)
+                return NULL;
+        ai = ptr;
+        ptr += base_size;
+
+        ai->groups[0].cpu_map = ptr;
+
+        for (unit = 0; unit < nr_units; unit++)
+                ai->groups[0].cpu_map[unit] = NR_CPUS;
+
+        ai->nr_groups = nr_groups;
+        ai->__ai_size = PFN_ALIGN(ai_size);
+
+        return ai;
+}
+
+/**
+ * pcpu_free_alloc_info - free percpu allocation info
+ * @ai: pcpu_alloc_info to free
+ *
+ * Free @ai which was allocated by pcpu_alloc_alloc_info().
+ */
+void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
+{
+        free_bootmem(__pa(ai), ai->__ai_size);
+}
+
+/**
+ * pcpu_build_alloc_info - build alloc_info considering distances between CPUs
  * @reserved_size: the size of reserved percpu area in bytes
  * @dyn_size: free size for dynamic allocation in bytes, -1 for auto
- * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto
- * @base_addr: mapped address, NULL for auto
- * @populate_pte_fn: callback to allocate pagetable, NULL if unnecessary
+ * @atom_size: allocation atom size
+ * @cpu_distance_fn: callback to determine distance between cpus, optional
+ *
+ * This function determines grouping of units, their mappings to cpus
+ * and other parameters considering needed percpu size, allocation
+ * atom size and distances between CPUs.
+ *
+ * Groups are always mutliples of atom size and CPUs which are of
+ * LOCAL_DISTANCE both ways are grouped together and share space for
+ * units in the same group.  The returned configuration is guaranteed
+ * to have CPUs on different nodes on different groups and >=75% usage
+ * of allocated virtual address space.
+ *
+ * RETURNS:
+ * On success, pointer to the new allocation_info is returned.  On
+ * failure, ERR_PTR value is returned.
+ */
+struct pcpu_alloc_info * __init pcpu_build_alloc_info(
+                                size_t reserved_size, ssize_t dyn_size,
+                                size_t atom_size,
+                                pcpu_fc_cpu_distance_fn_t cpu_distance_fn)
+{
+        static int group_map[NR_CPUS] __initdata;
+        static int group_cnt[NR_CPUS] __initdata;
+        const size_t static_size = __per_cpu_end - __per_cpu_start;
+        int group_cnt_max = 0, nr_groups = 1, nr_units = 0;
+        size_t size_sum, min_unit_size, alloc_size;
+        int upa, max_upa, uninitialized_var(best_upa);  /* units_per_alloc */
+        int last_allocs, group, unit;
+        unsigned int cpu, tcpu;
+        struct pcpu_alloc_info *ai;
+        unsigned int *cpu_map;
+
+        /* this function may be called multiple times */
+        memset(group_map, 0, sizeof(group_map));
+        memset(group_cnt, 0, sizeof(group_map));
+
+        /*
+         * Determine min_unit_size, alloc_size and max_upa such that
+         * alloc_size is multiple of atom_size and is the smallest
+         * which can accomodate 4k aligned segments which are equal to
+         * or larger than min_unit_size.
+         */
+        size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size);
+        min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
+
+        alloc_size = roundup(min_unit_size, atom_size);
+        upa = alloc_size / min_unit_size;
+        while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
+                upa--;
+        max_upa = upa;
+
+        /* group cpus according to their proximity */
+        for_each_possible_cpu(cpu) {
+                group = 0;
+        next_group:
+                for_each_possible_cpu(tcpu) {
+                        if (cpu == tcpu)
+                                break;
+                        if (group_map[tcpu] == group && cpu_distance_fn &&
+                            (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE ||
+                             cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) {
+                                group++;
+                                nr_groups = max(nr_groups, group + 1);
+                                goto next_group;
+                        }
+                }
+                group_map[cpu] = group;
+                group_cnt[group]++;
+                group_cnt_max = max(group_cnt_max, group_cnt[group]);
+        }
+
+        /*
+         * Expand unit size until address space usage goes over 75%
+         * and then as much as possible without using more address
+         * space.
+         */
+        last_allocs = INT_MAX;
+        for (upa = max_upa; upa; upa--) {
+                int allocs = 0, wasted = 0;
+
+                if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
+                        continue;
+
+                for (group = 0; group < nr_groups; group++) {
+                        int this_allocs = DIV_ROUND_UP(group_cnt[group], upa);
+                        allocs += this_allocs;
+                        wasted += this_allocs * upa - group_cnt[group];
+                }
+
+                /*
+                 * Don't accept if wastage is over 25%.  The
+                 * greater-than comparison ensures upa==1 always
+                 * passes the following check.
+                 */
+                if (wasted > num_possible_cpus() / 3)
+                        continue;
+
+                /* and then don't consume more memory */
+                if (allocs > last_allocs)
+                        break;
+                last_allocs = allocs;
+                best_upa = upa;
+        }
+        upa = best_upa;
+
+        /* allocate and fill alloc_info */
+        for (group = 0; group < nr_groups; group++)
+                nr_units += roundup(group_cnt[group], upa);
+
+        ai = pcpu_alloc_alloc_info(nr_groups, nr_units);
+        if (!ai)
+                return ERR_PTR(-ENOMEM);
+        cpu_map = ai->groups[0].cpu_map;
+
+        for (group = 0; group < nr_groups; group++) {
+                ai->groups[group].cpu_map = cpu_map;
+                cpu_map += roundup(group_cnt[group], upa);
+        }
+
+        ai->static_size = static_size;
+        ai->reserved_size = reserved_size;
+        ai->dyn_size = dyn_size;
+        ai->unit_size = alloc_size / upa;
+        ai->atom_size = atom_size;
+        ai->alloc_size = alloc_size;
+
+        for (group = 0, unit = 0; group_cnt[group]; group++) {
+                struct pcpu_group_info *gi = &ai->groups[group];
+
+                /*
+                 * Initialize base_offset as if all groups are located
+                 * back-to-back.  The caller should update this to
+                 * reflect actual allocation.
+                 */
+                gi->base_offset = unit * ai->unit_size;
+
+                for_each_possible_cpu(cpu)
+                        if (group_map[cpu] == group)
+                                gi->cpu_map[gi->nr_units++] = cpu;
+                gi->nr_units = roundup(gi->nr_units, upa);
+                unit += gi->nr_units;
+        }
+        BUG_ON(unit != nr_units);
+
+        return ai;
+}
+
+/**
+ * pcpu_dump_alloc_info - print out information about pcpu_alloc_info
+ * @lvl: loglevel
+ * @ai: allocation info to dump
+ *
+ * Print out information about @ai using loglevel @lvl.
+ */
+static void pcpu_dump_alloc_info(const char *lvl,
+                                 const struct pcpu_alloc_info *ai)
+{
+        int group_width = 1, cpu_width = 1, width;
+        char empty_str[] = "--------";
+        int alloc = 0, alloc_end = 0;
+        int group, v;
+        int upa, apl;   /* units per alloc, allocs per line */
+
+        v = ai->nr_groups;
+        while (v /= 10)
+                group_width++;
+
+        v = num_possible_cpus();
+        while (v /= 10)
+                cpu_width++;
+        empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0';
+
+        upa = ai->alloc_size / ai->unit_size;
+        width = upa * (cpu_width + 1) + group_width + 3;
+        apl = rounddown_pow_of_two(max(60 / width, 1));
+
+        printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu",
+               lvl, ai->static_size, ai->reserved_size, ai->dyn_size,
+               ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size);
+
+        for (group = 0; group < ai->nr_groups; group++) {
+                const struct pcpu_group_info *gi = &ai->groups[group];
+                int unit = 0, unit_end = 0;
+
+                BUG_ON(gi->nr_units % upa);
+                for (alloc_end += gi->nr_units / upa;
+                     alloc < alloc_end; alloc++) {
+                        if (!(alloc % apl)) {
+                                printk("\n");
+                                printk("%spcpu-alloc: ", lvl);
+                        }
+                        printk("[%0*d] ", group_width, group);
+
+                        for (unit_end += upa; unit < unit_end; unit++)
+                                if (gi->cpu_map[unit] != NR_CPUS)
+                                        printk("%0*d ", cpu_width,
+                                               gi->cpu_map[unit]);
+                                else
+                                        printk("%s ", empty_str);
+                }
+        }
+        printk("\n");
+}
+
+/**
+ * pcpu_setup_first_chunk - initialize the first percpu chunk
+ * @ai: pcpu_alloc_info describing how to percpu area is shaped
+ * @base_addr: mapped address
  *
  * Initialize the first percpu chunk which contains the kernel static
  * perpcu area.  This function is to be called from arch percpu area
- * setup path.  The first two parameters are mandatory.  The rest are
- * optional.
- *
- * @get_page_fn() should return pointer to percpu page given cpu
- * number and page number.  It should at least return enough pages to
- * cover the static area.  The returned pages for static area should
- * have been initialized with valid data.  If @unit_size is specified,
- * it can also return pages after the static area.  NULL return
- * indicates end of pages for the cpu.  Note that @get_page_fn() must
- * return the same number of pages for all cpus.
- *
- * @reserved_size, if non-zero, specifies the amount of bytes to
+ * setup path.
+ *
+ * @ai contains all information necessary to initialize the first
+ * chunk and prime the dynamic percpu allocator.
+ *
+ * @ai->static_size is the size of static percpu area.
+ *
+ * @ai->reserved_size, if non-zero, specifies the amount of bytes to
  * reserve after the static area in the first chunk.  This reserves
  * the first chunk such that it's available only through reserved
  * percpu allocation.  This is primarily used to serve module percpu
@@ -1018,22 +1557,29 @@ EXPORT_SYMBOL_GPL(free_percpu);
  * limited offset range for symbol relocations to guarantee module
  * percpu symbols fall inside the relocatable range.
  *
- * @dyn_size, if non-negative, determines the number of bytes
- * available for dynamic allocation in the first chunk.  Specifying
- * non-negative value makes percpu leave alone the area beyond
- * @static_size + @reserved_size + @dyn_size.
+ * @ai->dyn_size determines the number of bytes available for dynamic
+ * allocation in the first chunk.  The area between @ai->static_size +
+ * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused.
+ *
+ * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE
+ * and equal to or larger than @ai->static_size + @ai->reserved_size +
+ * @ai->dyn_size.
+ *
+ * @ai->atom_size is the allocation atom size and used as alignment
+ * for vm areas.
  *
- * @unit_size, if non-negative, specifies unit size and must be
- * aligned to PAGE_SIZE and equal to or larger than @static_size +
- * @reserved_size + if non-negative, @dyn_size.
+ * @ai->alloc_size is the allocation size and always multiple of
+ * @ai->atom_size.  This is larger than @ai->atom_size if
+ * @ai->unit_size is larger than @ai->atom_size.
  *
- * Non-null @base_addr means that the caller already allocated virtual
- * region for the first chunk and mapped it.  percpu must not mess
- * with the chunk.  Note that @base_addr with 0 @unit_size or non-NULL
- * @populate_pte_fn doesn't make any sense.
+ * @ai->nr_groups and @ai->groups describe virtual memory layout of
+ * percpu areas.  Units which should be colocated are put into the
+ * same group.  Dynamic VM areas will be allocated according to these
+ * groupings.  If @ai->nr_groups is zero, a single group containing
+ * all units is assumed.
  *
- * @populate_pte_fn is used to populate the pagetable.  NULL means the
- * caller already populated the pagetable.
+ * The caller should have mapped the first chunk at @base_addr and
+ * copied static data to each unit.
  *
  * If the first chunk ends up with both reserved and dynamic areas, it
  * is served by two chunks - one to serve the core static and reserved
@@ -1043,49 +1589,98 @@ EXPORT_SYMBOL_GPL(free_percpu);
  * and available for dynamic allocation like any other chunks.
  *
  * RETURNS:
- * The determined pcpu_unit_size which can be used to initialize
- * percpu access.
+ * 0 on success, -errno on failure.
  */
-size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
-                                     size_t static_size, size_t reserved_size,
-                                     ssize_t dyn_size, ssize_t unit_size,
-                                     void *base_addr,
-                                     pcpu_populate_pte_fn_t populate_pte_fn)
+int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
+                                  void *base_addr)
 {
-        static struct vm_struct first_vm;
+        static char cpus_buf[4096] __initdata;
         static int smap[2], dmap[2];
-        size_t size_sum = static_size + reserved_size +
-                          (dyn_size >= 0 ? dyn_size : 0);
+        size_t dyn_size = ai->dyn_size;
+        size_t size_sum = ai->static_size + ai->reserved_size + dyn_size;
         struct pcpu_chunk *schunk, *dchunk = NULL;
+        unsigned long *group_offsets;
+        size_t *group_sizes;
+        unsigned long *unit_off;
         unsigned int cpu;
-        int nr_pages;
-        int err, i;
+        int *unit_map;
+        int group, unit, i;
+
+        cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask);
+
+#define PCPU_SETUP_BUG_ON(cond) do {                                    \
+        if (unlikely(cond)) {                                           \
+                pr_emerg("PERCPU: failed to initialize, %s", #cond);    \
+                pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf);   \
+                pcpu_dump_alloc_info(KERN_EMERG, ai);                   \
+                BUG();                                                  \
+        }                                                               \
+} while (0)
 
-        /* santiy checks */
+        /* sanity checks */
         BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC ||
                      ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC);
-        BUG_ON(!static_size);
-        if (unit_size >= 0) {
-                BUG_ON(unit_size < size_sum);
-                BUG_ON(unit_size & ~PAGE_MASK);
-                BUG_ON(unit_size < PCPU_MIN_UNIT_SIZE);
-        } else
-                BUG_ON(base_addr);
-        BUG_ON(base_addr && populate_pte_fn);
-
-        if (unit_size >= 0)
-                pcpu_unit_pages = unit_size >> PAGE_SHIFT;
-        else
-                pcpu_unit_pages = max_t(int, PCPU_MIN_UNIT_SIZE >> PAGE_SHIFT,
-                                        PFN_UP(size_sum));
+        PCPU_SETUP_BUG_ON(ai->nr_groups <= 0);
+        PCPU_SETUP_BUG_ON(!ai->static_size);
+        PCPU_SETUP_BUG_ON(!base_addr);
+        PCPU_SETUP_BUG_ON(ai->unit_size < size_sum);
+        PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK);
+        PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
+
+        /* process group information and build config tables accordingly */
+        group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
+        group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0]));
+        unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0]));
+        unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));
+
+        for (cpu = 0; cpu < nr_cpu_ids; cpu++)
+                unit_map[cpu] = UINT_MAX;
+        pcpu_first_unit_cpu = NR_CPUS;
+
+        for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
+                const struct pcpu_group_info *gi = &ai->groups[group];
+
+                group_offsets[group] = gi->base_offset;
+                group_sizes[group] = gi->nr_units * ai->unit_size;
+
+                for (i = 0; i < gi->nr_units; i++) {
+                        cpu = gi->cpu_map[i];
+                        if (cpu == NR_CPUS)
+                                continue;
 
-        pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
-        pcpu_chunk_size = nr_cpu_ids * pcpu_unit_size;
-        pcpu_chunk_struct_size = sizeof(struct pcpu_chunk)
-                + nr_cpu_ids * pcpu_unit_pages * sizeof(struct page *);
+                        PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids);
+                        PCPU_SETUP_BUG_ON(!cpu_possible(cpu));
+                        PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX);
 
-        if (dyn_size < 0)
-                dyn_size = pcpu_unit_size - static_size - reserved_size;
+                        unit_map[cpu] = unit + i;
+                        unit_off[cpu] = gi->base_offset + i * ai->unit_size;
+
+                        if (pcpu_first_unit_cpu == NR_CPUS)
+                                pcpu_first_unit_cpu = cpu;
+                }
+        }
+        pcpu_last_unit_cpu = cpu;
+        pcpu_nr_units = unit;
+
+        for_each_possible_cpu(cpu)
+                PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX);
+
+        /* we're done parsing the input, undefine BUG macro and dump config */
+#undef PCPU_SETUP_BUG_ON
+        pcpu_dump_alloc_info(KERN_INFO, ai);
+
+        pcpu_nr_groups = ai->nr_groups;
+        pcpu_group_offsets = group_offsets;
+        pcpu_group_sizes = group_sizes;
+        pcpu_unit_map = unit_map;
+        pcpu_unit_offsets = unit_off;
+
+        /* determine basic parameters */
+        pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT;
+        pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
+        pcpu_atom_size = ai->atom_size;
+        pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
+                BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);
 
         /*
          * Allocate chunk slots.  The additional last slot is for
@@ -1105,189 +1700,368 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
          */
         schunk = alloc_bootmem(pcpu_chunk_struct_size);
         INIT_LIST_HEAD(&schunk->list);
-        schunk->vm = &first_vm;
+        schunk->base_addr = base_addr;
         schunk->map = smap;
         schunk->map_alloc = ARRAY_SIZE(smap);
-        schunk->page = schunk->page_ar;
+        schunk->immutable = true;
+        bitmap_fill(schunk->populated, pcpu_unit_pages);
 
-        if (reserved_size) {
-                schunk->free_size = reserved_size;
+        if (ai->reserved_size) {
+                schunk->free_size = ai->reserved_size;
                 pcpu_reserved_chunk = schunk;
-                pcpu_reserved_chunk_limit = static_size + reserved_size;
+                pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size;
         } else {
                 schunk->free_size = dyn_size;
                 dyn_size = 0;                   /* dynamic area covered */
         }
         schunk->contig_hint = schunk->free_size;
 
-        schunk->map[schunk->map_used++] = -static_size;
+        schunk->map[schunk->map_used++] = -ai->static_size;
         if (schunk->free_size)
                 schunk->map[schunk->map_used++] = schunk->free_size;
 
         /* init dynamic chunk if necessary */
         if (dyn_size) {
-                dchunk = alloc_bootmem(sizeof(struct pcpu_chunk));
+                dchunk = alloc_bootmem(pcpu_chunk_struct_size);
                 INIT_LIST_HEAD(&dchunk->list);
-                dchunk->vm = &first_vm;
+                dchunk->base_addr = base_addr;
                 dchunk->map = dmap;
                 dchunk->map_alloc = ARRAY_SIZE(dmap);
-                dchunk->page = schunk->page_ar; /* share page map with schunk */
+                dchunk->immutable = true;
+                bitmap_fill(dchunk->populated, pcpu_unit_pages);
 
                 dchunk->contig_hint = dchunk->free_size = dyn_size;
                 dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit;
                 dchunk->map[dchunk->map_used++] = dchunk->free_size;
         }
 
-        /* allocate vm address */
-        first_vm.flags = VM_ALLOC;
-        first_vm.size = pcpu_chunk_size;
-
-        if (!base_addr)
-                vm_area_register_early(&first_vm, PAGE_SIZE);
-        else {
-                /*
-                 * Pages already mapped.  No need to remap into
-                 * vmalloc area.  In this case the first chunks can't
-                 * be mapped or unmapped by percpu and are marked
-                 * immutable.
-                 */
-                first_vm.addr = base_addr;
-                schunk->immutable = true;
-                if (dchunk)
-                        dchunk->immutable = true;
-        }
-
-        /* assign pages */
-        nr_pages = -1;
-        for_each_possible_cpu(cpu) {
-                for (i = 0; i < pcpu_unit_pages; i++) {
-                        struct page *page = get_page_fn(cpu, i);
-
-                        if (!page)
-                                break;
-                        *pcpu_chunk_pagep(schunk, cpu, i) = page;
-                }
-
-                BUG_ON(i < PFN_UP(static_size));
-
-                if (nr_pages < 0)
-                        nr_pages = i;
-                else
-                        BUG_ON(nr_pages != i);
-        }
-
-        /* map them */
-        if (populate_pte_fn) {
-                for_each_possible_cpu(cpu)
-                        for (i = 0; i < nr_pages; i++)
-                                populate_pte_fn(pcpu_chunk_addr(schunk,
-                                                                cpu, i));
-
-                err = pcpu_map(schunk, 0, nr_pages);
-                if (err)
-                        panic("failed to setup static percpu area, err=%d\n",
-                              err);
-        }
-
         /* link the first chunk in */
         pcpu_first_chunk = dchunk ?: schunk;
         pcpu_chunk_relocate(pcpu_first_chunk, -1);
 
         /* we're done */
-        pcpu_base_addr = (void *)pcpu_chunk_addr(schunk, 0, 0);
-        return pcpu_unit_size;
+        pcpu_base_addr = base_addr;
+        return 0;
 }
 
-/*
- * Embedding first chunk setup helper.
- */
-static void *pcpue_ptr __initdata;
-static size_t pcpue_size __initdata;
-static size_t pcpue_unit_size __initdata;
+const char *pcpu_fc_names[PCPU_FC_NR] __initdata = {
+        [PCPU_FC_AUTO]  = "auto",
+        [PCPU_FC_EMBED] = "embed",
+        [PCPU_FC_PAGE]  = "page",
+};
 
-static struct page * __init pcpue_get_page(unsigned int cpu, int pageno)
-{
-        size_t off = (size_t)pageno << PAGE_SHIFT;
+enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO;
 
-        if (off >= pcpue_size)
-                return NULL;
+static int __init percpu_alloc_setup(char *str)
+{
+        if (0)
+                /* nada */;
+#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
+        else if (!strcmp(str, "embed"))
+                pcpu_chosen_fc = PCPU_FC_EMBED;
+#endif
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+        else if (!strcmp(str, "page"))
+                pcpu_chosen_fc = PCPU_FC_PAGE;
+#endif
+        else
+                pr_warning("PERCPU: unknown allocator %s specified\n", str);
 
-        return virt_to_page(pcpue_ptr + cpu * pcpue_unit_size + off);
+        return 0;
 }
+early_param("percpu_alloc", percpu_alloc_setup);
 
+#if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \
+        !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 /**
  * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem
- * @static_size: the size of static percpu area in bytes
  * @reserved_size: the size of reserved percpu area in bytes
  * @dyn_size: free size for dynamic allocation in bytes, -1 for auto
- * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto
+ * @atom_size: allocation atom size
+ * @cpu_distance_fn: callback to determine distance between cpus, optional
+ * @alloc_fn: function to allocate percpu page
+ * @free_fn: funtion to free percpu page
  *
  * This is a helper to ease setting up embedded first percpu chunk and
  * can be called where pcpu_setup_first_chunk() is expected.
  *
  * If this function is used to setup the first chunk, it is allocated
- * as a contiguous area using bootmem allocator and used as-is without
- * being mapped into vmalloc area.  This enables the first chunk to
- * piggy back on the linear physical mapping which often uses larger
- * page size.
+ * by calling @alloc_fn and used as-is without being mapped into
+ * vmalloc area.  Allocations are always whole multiples of @atom_size
+ * aligned to @atom_size.
+ *
+ * This enables the first chunk to piggy back on the linear physical
+ * mapping which often uses larger page size.  Please note that this
+ * can result in very sparse cpu->unit mapping on NUMA machines thus
+ * requiring large vmalloc address space.  Don't use this allocator if
+ * vmalloc space is not orders of magnitude larger than distances
+ * between node memory addresses (ie. 32bit NUMA machines).
  *
  * When @dyn_size is positive, dynamic area might be larger than
- * specified to fill page alignment.  Also, when @dyn_size is auto,
- * @dyn_size does not fill the whole first chunk but only what's
- * necessary for page alignment after static and reserved areas.
+ * specified to fill page alignment.  When @dyn_size is auto,
+ * @dyn_size is just big enough to fill page alignment after static
+ * and reserved areas.
  *
  * If the needed size is smaller than the minimum or specified unit
- * size, the leftover is returned to the bootmem allocator.
+ * size, the leftover is returned using @free_fn.
  *
  * RETURNS:
- * The determined pcpu_unit_size which can be used to initialize
- * percpu access on success, -errno on failure.
+ * 0 on success, -errno on failure.
  */
-ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size,
-                                      ssize_t dyn_size, ssize_t unit_size)
+int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
+                                  size_t atom_size,
+                                  pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
+                                  pcpu_fc_alloc_fn_t alloc_fn,
+                                  pcpu_fc_free_fn_t free_fn)
 {
-        size_t chunk_size;
-        unsigned int cpu;
+        void *base = (void *)ULONG_MAX;
+        void **areas = NULL;
+        struct pcpu_alloc_info *ai;
+        size_t size_sum, areas_size, max_distance;
+        int group, i, rc;
+
+        ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size,
+                                   cpu_distance_fn);
+        if (IS_ERR(ai))
+                return PTR_ERR(ai);
+
+        size_sum = ai->static_size + ai->reserved_size + ai->dyn_size;
+        areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *));
+
+        areas = alloc_bootmem_nopanic(areas_size);
+        if (!areas) {
+                rc = -ENOMEM;
+                goto out_free;
+        }
 
-        /* determine parameters and allocate */
-        pcpue_size = PFN_ALIGN(static_size + reserved_size +
-                               (dyn_size >= 0 ? dyn_size : 0));
-        if (dyn_size != 0)
-                dyn_size = pcpue_size - static_size - reserved_size;
-
-        if (unit_size >= 0) {
-                BUG_ON(unit_size < pcpue_size);
-                pcpue_unit_size = unit_size;
-        } else
-                pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE);
-
-        chunk_size = pcpue_unit_size * nr_cpu_ids;
-
-        pcpue_ptr = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE,
-                                            __pa(MAX_DMA_ADDRESS));
-        if (!pcpue_ptr) {
-                pr_warning("PERCPU: failed to allocate %zu bytes for "
-                           "embedding\n", chunk_size);
-                return -ENOMEM;
+        /* allocate, copy and determine base address */
+        for (group = 0; group < ai->nr_groups; group++) {
+                struct pcpu_group_info *gi = &ai->groups[group];
+                unsigned int cpu = NR_CPUS;
+                void *ptr;
+
+                for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++)
+                        cpu = gi->cpu_map[i];
+                BUG_ON(cpu == NR_CPUS);
+
+                /* allocate space for the whole group */
+                ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size);
+                if (!ptr) {
+                        rc = -ENOMEM;
+                        goto out_free_areas;
+                }
+                areas[group] = ptr;
+
+                base = min(ptr, base);
+
+                for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) {
+                        if (gi->cpu_map[i] == NR_CPUS) {
+                                /* unused unit, free whole */
+                                free_fn(ptr, ai->unit_size);
+                                continue;
+                        }
+                        /* copy and return the unused part */
+                        memcpy(ptr, __per_cpu_load, ai->static_size);
+                        free_fn(ptr + size_sum, ai->unit_size - size_sum);
+                }
         }
 
-        /* return the leftover and copy */
-        for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
-                void *ptr = pcpue_ptr + cpu * pcpue_unit_size;
+        /* base address is now known, determine group base offsets */
+        max_distance = 0;
+        for (group = 0; group < ai->nr_groups; group++) {
+                ai->groups[group].base_offset = areas[group] - base;
+                max_distance = max_t(size_t, max_distance,
+                                     ai->groups[group].base_offset);
+        }
+        max_distance += ai->unit_size;
+
+        /* warn if maximum distance is further than 75% of vmalloc space */
+        if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) {
+                pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc "
+                           "space 0x%lx\n",
+                           max_distance, VMALLOC_END - VMALLOC_START);
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+                /* and fail if we have fallback */
+                rc = -EINVAL;
+                goto out_free;
+#endif
+        }
+
+        pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n",
+                PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size,
+                ai->dyn_size, ai->unit_size);
+
+        rc = pcpu_setup_first_chunk(ai, base);
+        goto out_free;
+
+out_free_areas:
+        for (group = 0; group < ai->nr_groups; group++)
+                free_fn(areas[group],
+                        ai->groups[group].nr_units * ai->unit_size);
+out_free:
+        pcpu_free_alloc_info(ai);
+        if (areas)
+                free_bootmem(__pa(areas), areas_size);
+        return rc;
+}
+#endif /* CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK ||
+          !CONFIG_HAVE_SETUP_PER_CPU_AREA */
+
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+/**
+ * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages
+ * @reserved_size: the size of reserved percpu area in bytes
+ * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE
+ * @free_fn: funtion to free percpu page, always called with PAGE_SIZE
+ * @populate_pte_fn: function to populate pte
+ *
+ * This is a helper to ease setting up page-remapped first percpu
+ * chunk and can be called where pcpu_setup_first_chunk() is expected.
+ *
+ * This is the basic allocator.  Static percpu area is allocated
+ * page-by-page into vmalloc area.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init pcpu_page_first_chunk(size_t reserved_size,
+                                 pcpu_fc_alloc_fn_t alloc_fn,
+                                 pcpu_fc_free_fn_t free_fn,
+                                 pcpu_fc_populate_pte_fn_t populate_pte_fn)
+{
+        static struct vm_struct vm;
+        struct pcpu_alloc_info *ai;
+        char psize_str[16];
+        int unit_pages;
+        size_t pages_size;
+        struct page **pages;
+        int unit, i, j, rc;
+
+        snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10);
+
+        ai = pcpu_build_alloc_info(reserved_size, -1, PAGE_SIZE, NULL);
+        if (IS_ERR(ai))
+                return PTR_ERR(ai);
+        BUG_ON(ai->nr_groups != 1);
+        BUG_ON(ai->groups[0].nr_units != num_possible_cpus());
+
+        unit_pages = ai->unit_size >> PAGE_SHIFT;
+
+        /* unaligned allocations can't be freed, round up to page size */
+        pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() *
+                               sizeof(pages[0]));
+        pages = alloc_bootmem(pages_size);
+
+        /* allocate pages */
+        j = 0;
+        for (unit = 0; unit < num_possible_cpus(); unit++)
+                for (i = 0; i < unit_pages; i++) {
+                        unsigned int cpu = ai->groups[0].cpu_map[unit];
+                        void *ptr;
+
+                        ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE);
+                        if (!ptr) {
+                                pr_warning("PERCPU: failed to allocate %s page "
+                                           "for cpu%u\n", psize_str, cpu);
+                                goto enomem;
+                        }
+                        pages[j++] = virt_to_page(ptr);
+                }
+
+        /* allocate vm area, map the pages and copy static data */
+        vm.flags = VM_ALLOC;
+        vm.size = num_possible_cpus() * ai->unit_size;
+        vm_area_register_early(&vm, PAGE_SIZE);
+
+        for (unit = 0; unit < num_possible_cpus(); unit++) {
+                unsigned long unit_addr =
+                        (unsigned long)vm.addr + unit * ai->unit_size;
+
+                for (i = 0; i < unit_pages; i++)
+                        populate_pte_fn(unit_addr + (i << PAGE_SHIFT));
 
-                if (cpu_possible(cpu)) {
-                        free_bootmem(__pa(ptr + pcpue_size),
-                                     pcpue_unit_size - pcpue_size);
-                        memcpy(ptr, __per_cpu_load, static_size);
-                } else
-                        free_bootmem(__pa(ptr), pcpue_unit_size);
+                /* pte already populated, the following shouldn't fail */
+                rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages],
+                                      unit_pages);
+                if (rc < 0)
+                        panic("failed to map percpu area, err=%d\n", rc);
+
+                /*
+                 * FIXME: Archs with virtual cache should flush local
+                 * cache for the linear mapping here - something
+                 * equivalent to flush_cache_vmap() on the local cpu.
+                 * flush_cache_vmap() can't be used as most supporting
+                 * data structures are not set up yet.
+                 */
+
+                /* copy static data */
+                memcpy((void *)unit_addr, __per_cpu_load, ai->static_size);
         }
 
         /* we're ready, commit */
-        pr_info("PERCPU: Embedded %zu pages at %p, static data %zu bytes\n",
-                pcpue_size >> PAGE_SHIFT, pcpue_ptr, static_size);
+        pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n",
+                unit_pages, psize_str, vm.addr, ai->static_size,
+                ai->reserved_size, ai->dyn_size);
+
+        rc = pcpu_setup_first_chunk(ai, vm.addr);
+        goto out_free_ar;
+
+enomem:
+        while (--j >= 0)
+                free_fn(page_address(pages[j]), PAGE_SIZE);
+        rc = -ENOMEM;
+out_free_ar:
+        free_bootmem(__pa(pages), pages_size);
+        pcpu_free_alloc_info(ai);
+        return rc;
+}
+#endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */
+
+/*
+ * Generic percpu area setup.
+ *
+ * The embedding helper is used because its behavior closely resembles
+ * the original non-dynamic generic percpu area setup.  This is
+ * important because many archs have addressing restrictions and might
+ * fail if the percpu area is located far away from the previous
+ * location.  As an added bonus, in non-NUMA cases, embedding is
+ * generally a good idea TLB-wise because percpu area can piggy back
+ * on the physical linear memory mapping which uses large page
+ * mappings on applicable archs.
+ */
+#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(__per_cpu_offset);
+
+static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size,
+                                       size_t align)
+{
+        return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS));
+}
 
-        return pcpu_setup_first_chunk(pcpue_get_page, static_size,
-                                      reserved_size, dyn_size,
-                                      pcpue_unit_size, pcpue_ptr, NULL);
+static void __init pcpu_dfl_fc_free(void *ptr, size_t size)
+{
+        free_bootmem(__pa(ptr), size);
+}
+
+void __init setup_per_cpu_areas(void)
+{
+        unsigned long delta;
+        unsigned int cpu;
+        int rc;
+
+        /*
+         * Always reserve area for module percpu variables.  That's
+         * what the legacy allocator did.
+         */
+        rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
+                                    PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL,
+                                    pcpu_dfl_fc_alloc, pcpu_dfl_fc_free);
+        if (rc < 0)
+                panic("Failed to initialized percpu areas.");
+
+        delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
+        for_each_possible_cpu(cpu)
+                __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
 }
+#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
diff --git a/mm/quicklist.c b/mm/quicklist.c
index e66d07d1b4ff..6633965bb27b 100644
--- a/mm/quicklist.c
+++ b/mm/quicklist.c
@@ -19,7 +19,7 @@
 #include <linux/module.h>
 #include <linux/quicklist.h>
 
-DEFINE_PER_CPU(struct quicklist, quicklist)[CONFIG_NR_QUICK];
+DEFINE_PER_CPU(struct quicklist [CONFIG_NR_QUICK], quicklist);
 
 #define FRACTION_OF_NODE_MEM    16
 
@@ -29,7 +29,6 @@ static unsigned long max_pages(unsigned long min_pages)
         int node = numa_node_id();
         struct zone *zones = NODE_DATA(node)->node_zones;
         int num_cpus_on_node;
-        const struct cpumask *cpumask_on_node = cpumask_of_node(node);
 
         node_free_pages =
 #ifdef CONFIG_ZONE_DMA
@@ -42,7 +41,7 @@ static unsigned long max_pages(unsigned long min_pages)
 
         max = node_free_pages / FRACTION_OF_NODE_MEM;
 
-        num_cpus_on_node = cpus_weight_nr(*cpumask_on_node);
+        num_cpus_on_node = cpumask_weight(cpumask_of_node(node));
         max /= num_cpus_on_node;
 
         return max(max, min_pages);
diff --git a/mm/rmap.c b/mm/rmap.c
index 0895b5c7cbff..dd43373a483f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -36,6 +36,11 @@
  *                 mapping->tree_lock (widely used, in set_page_dirty,
  *                           in arch-dependent flush_dcache_mmap_lock,
  *                           within inode_lock in __sync_single_inode)
+ *
+ * (code doesn't rely on that order so it could be switched around)
+ * ->tasklist_lock
+ *   anon_vma->lock      (memory_failure, collect_procs_anon)
+ *     pte map lock
  */
 
 #include <linux/mm.h>
@@ -191,7 +196,7 @@ void __init anon_vma_init(void)
  * Getting a lock on a stable anon_vma from a page off the LRU is
  * tricky: page_lock_anon_vma rely on RCU to guard against the races.
  */
-static struct anon_vma *page_lock_anon_vma(struct page *page)
+struct anon_vma *page_lock_anon_vma(struct page *page)
 {
         struct anon_vma *anon_vma;
         unsigned long anon_mapping;
@@ -211,7 +216,7 @@ out:
         return NULL;
 }
 
-static void page_unlock_anon_vma(struct anon_vma *anon_vma)
+void page_unlock_anon_vma(struct anon_vma *anon_vma)
 {
         spin_unlock(&anon_vma->lock);
         rcu_read_unlock();
@@ -237,8 +242,8 @@ vma_address(struct page *page, struct vm_area_struct *vma)
 }
 
 /*
- * At what user virtual address is page expected in vma? checking that the
- * page matches the vma: currently only used on anon pages, by unuse_vma;
+ * At what user virtual address is page expected in vma?
+ * checking that the page matches the vma.
  */
 unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
 {
@@ -311,7 +316,7 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
  * if the page is not mapped into the page tables of this VMA.  Only
  * valid for normal file or anonymous VMAs.
  */
-static int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
+int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
 {
         unsigned long address;
         pte_t *pte;
@@ -710,27 +715,6 @@ void page_add_file_rmap(struct page *page)
         }
 }
 
-#ifdef CONFIG_DEBUG_VM
-/**
- * page_dup_rmap - duplicate pte mapping to a page
- * @page:       the page to add the mapping to
- * @vma:        the vm area being duplicated
- * @address:    the user virtual address mapped
- *
- * For copy_page_range only: minimal extract from page_add_file_rmap /
- * page_add_anon_rmap, avoiding unnecessary tests (already checked) so it's
- * quicker.
- *
- * The caller needs to hold the pte lock.
- */
-void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address)
-{
-        if (PageAnon(page))
-                __page_check_anon_rmap(page, vma, address);
-        atomic_inc(&page->_mapcount);
-}
-#endif
-
 /**
  * page_remove_rmap - take down pte mapping from a page
  * @page: page to remove mapping from
@@ -739,34 +723,37 @@ void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long
  */
 void page_remove_rmap(struct page *page)
 {
-        if (atomic_add_negative(-1, &page->_mapcount)) {
-                /*
-                 * Now that the last pte has gone, s390 must transfer dirty
-                 * flag from storage key to struct page.  We can usually skip
-                 * this if the page is anon, so about to be freed; but perhaps
-                 * not if it's in swapcache - there might be another pte slot
-                 * containing the swap entry, but page not yet written to swap.
-                 */
-                if ((!PageAnon(page) || PageSwapCache(page)) &&
-                    page_test_dirty(page)) {
-                        page_clear_dirty(page);
-                        set_page_dirty(page);
-                }
-                if (PageAnon(page))
-                        mem_cgroup_uncharge_page(page);
-                __dec_zone_page_state(page,
-                        PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
-                mem_cgroup_update_mapped_file_stat(page, -1);
-                /*
-                 * It would be tidy to reset the PageAnon mapping here,
-                 * but that might overwrite a racing page_add_anon_rmap
-                 * which increments mapcount after us but sets mapping
-                 * before us: so leave the reset to free_hot_cold_page,
-                 * and remember that it's only reliable while mapped.
-                 * Leaving it set also helps swapoff to reinstate ptes
-                 * faster for those pages still in swapcache.
-                 */
+        /* page still mapped by someone else? */
+        if (!atomic_add_negative(-1, &page->_mapcount))
+                return;
+
+        /*
+         * Now that the last pte has gone, s390 must transfer dirty
+         * flag from storage key to struct page.  We can usually skip
+         * this if the page is anon, so about to be freed; but perhaps
+         * not if it's in swapcache - there might be another pte slot
+         * containing the swap entry, but page not yet written to swap.
+         */
+        if ((!PageAnon(page) || PageSwapCache(page)) && page_test_dirty(page)) {
+                page_clear_dirty(page);
+                set_page_dirty(page);
+        }
+        if (PageAnon(page)) {
+                mem_cgroup_uncharge_page(page);
+                __dec_zone_page_state(page, NR_ANON_PAGES);
+        } else {
+                __dec_zone_page_state(page, NR_FILE_MAPPED);
         }
+        mem_cgroup_update_mapped_file_stat(page, -1);
+        /*
+         * It would be tidy to reset the PageAnon mapping here,
+         * but that might overwrite a racing page_add_anon_rmap
+         * which increments mapcount after us but sets mapping
+         * before us: so leave the reset to free_hot_cold_page,
+         * and remember that it's only reliable while mapped.
+         * Leaving it set also helps swapoff to reinstate ptes
+         * faster for those pages still in swapcache.
+         */
 }
 
 /*
@@ -774,7 +761,7 @@ void page_remove_rmap(struct page *page)
  * repeatedly from either try_to_unmap_anon or try_to_unmap_file.
  */
 static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
-                                int migration)
+                                enum ttu_flags flags)
 {
         struct mm_struct *mm = vma->vm_mm;
         unsigned long address;
@@ -796,11 +783,13 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
          * If it's recently referenced (perhaps page_referenced
          * skipped over this mm) then we should reactivate it.
          */
-        if (!migration) {
+        if (!(flags & TTU_IGNORE_MLOCK)) {
                 if (vma->vm_flags & VM_LOCKED) {
                         ret = SWAP_MLOCK;
                         goto out_unmap;
                 }
+        }
+        if (!(flags & TTU_IGNORE_ACCESS)) {
                 if (ptep_clear_flush_young_notify(vma, address, pte)) {
                         ret = SWAP_FAIL;
                         goto out_unmap;
@@ -818,7 +807,14 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
         /* Update high watermark before we lower rss */
         update_hiwater_rss(mm);
 
-        if (PageAnon(page)) {
+        if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
+                if (PageAnon(page))
+                        dec_mm_counter(mm, anon_rss);
+                else
+                        dec_mm_counter(mm, file_rss);
+                set_pte_at(mm, address, pte,
+                                swp_entry_to_pte(make_hwpoison_entry(page)));
+        } else if (PageAnon(page)) {
                 swp_entry_t entry = { .val = page_private(page) };
 
                 if (PageSwapCache(page)) {
@@ -840,12 +836,12 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                          * pte. do_swap_page() will wait until the migration
                          * pte is removed and then restart fault handling.
                          */
-                        BUG_ON(!migration);
+                        BUG_ON(TTU_ACTION(flags) != TTU_MIGRATION);
                         entry = make_migration_entry(page, pte_write(pteval));
                 }
                 set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
                 BUG_ON(pte_file(*pte));
-        } else if (PAGE_MIGRATION && migration) {
+        } else if (PAGE_MIGRATION && (TTU_ACTION(flags) == TTU_MIGRATION)) {
                 /* Establish migration entry for a file page */
                 swp_entry_t entry;
                 entry = make_migration_entry(page, pte_write(pteval));
@@ -1014,12 +1010,13 @@ static int try_to_mlock_page(struct page *page, struct vm_area_struct *vma)
  * vm_flags for that VMA.  That should be OK, because that vma shouldn't be
  * 'LOCKED.
  */
-static int try_to_unmap_anon(struct page *page, int unlock, int migration)
+static int try_to_unmap_anon(struct page *page, enum ttu_flags flags)
 {
         struct anon_vma *anon_vma;
         struct vm_area_struct *vma;
         unsigned int mlocked = 0;
         int ret = SWAP_AGAIN;
+        int unlock = TTU_ACTION(flags) == TTU_MUNLOCK;
 
         if (MLOCK_PAGES && unlikely(unlock))
                 ret = SWAP_SUCCESS;     /* default for try_to_munlock() */
@@ -1035,7 +1032,7 @@ static int try_to_unmap_anon(struct page *page, int unlock, int migration)
                                 continue;  /* must visit all unlocked vmas */
                         ret = SWAP_MLOCK;  /* saw at least one mlocked vma */
                 } else {
-                        ret = try_to_unmap_one(page, vma, migration);
+                        ret = try_to_unmap_one(page, vma, flags);
                         if (ret == SWAP_FAIL || !page_mapped(page))
                                 break;
                 }
@@ -1059,8 +1056,7 @@ static int try_to_unmap_anon(struct page *page, int unlock, int migration)
 /**
  * try_to_unmap_file - unmap/unlock file page using the object-based rmap method
  * @page: the page to unmap/unlock
- * @unlock:  request for unlock rather than unmap [unlikely]
- * @migration:  unmapping for migration - ignored if @unlock
+ * @flags: action and flags
  *
  * Find all the mappings of a page using the mapping pointer and the vma chains
  * contained in the address_space struct it points to.
@@ -1072,7 +1068,7 @@ static int try_to_unmap_anon(struct page *page, int unlock, int migration)
  * vm_flags for that VMA.  That should be OK, because that vma shouldn't be
  * 'LOCKED.
  */
-static int try_to_unmap_file(struct page *page, int unlock, int migration)
+static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
 {
         struct address_space *mapping = page->mapping;
         pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
@@ -1084,6 +1080,7 @@ static int try_to_unmap_file(struct page *page, int unlock, int migration)
         unsigned long max_nl_size = 0;
         unsigned int mapcount;
         unsigned int mlocked = 0;
+        int unlock = TTU_ACTION(flags) == TTU_MUNLOCK;
 
         if (MLOCK_PAGES && unlikely(unlock))
                 ret = SWAP_SUCCESS;     /* default for try_to_munlock() */
@@ -1096,7 +1093,7 @@ static int try_to_unmap_file(struct page *page, int unlock, int migration)
                                 continue;       /* must visit all vmas */
                         ret = SWAP_MLOCK;
                 } else {
-                        ret = try_to_unmap_one(page, vma, migration);
+                        ret = try_to_unmap_one(page, vma, flags);
                         if (ret == SWAP_FAIL || !page_mapped(page))
                                 goto out;
                 }
@@ -1121,7 +1118,8 @@ static int try_to_unmap_file(struct page *page, int unlock, int migration)
                         ret = SWAP_MLOCK;       /* leave mlocked == 0 */
                         goto out;               /* no need to look further */
                 }
-                if (!MLOCK_PAGES && !migration && (vma->vm_flags & VM_LOCKED))
+                if (!MLOCK_PAGES && !(flags & TTU_IGNORE_MLOCK) &&
+                        (vma->vm_flags & VM_LOCKED))
                         continue;
                 cursor = (unsigned long) vma->vm_private_data;
                 if (cursor > max_nl_cursor)
@@ -1155,7 +1153,7 @@ static int try_to_unmap_file(struct page *page, int unlock, int migration)
         do {
                 list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
                                                 shared.vm_set.list) {
-                        if (!MLOCK_PAGES && !migration &&
+                        if (!MLOCK_PAGES && !(flags & TTU_IGNORE_MLOCK) &&
                             (vma->vm_flags & VM_LOCKED))
                                 continue;
                         cursor = (unsigned long) vma->vm_private_data;
@@ -1195,7 +1193,7 @@ out:
 /**
  * try_to_unmap - try to remove all page table mappings to a page
  * @page: the page to get unmapped
- * @migration: migration flag
+ * @flags: action and flags
  *
  * Tries to remove all the page table entries which are mapping this
  * page, used in the pageout path.  Caller must hold the page lock.
@@ -1206,16 +1204,16 @@ out:
  * SWAP_FAIL    - the page is unswappable
  * SWAP_MLOCK   - page is mlocked.
  */
-int try_to_unmap(struct page *page, int migration)
+int try_to_unmap(struct page *page, enum ttu_flags flags)
 {
         int ret;
 
         BUG_ON(!PageLocked(page));
 
         if (PageAnon(page))
-                ret = try_to_unmap_anon(page, 0, migration);
+                ret = try_to_unmap_anon(page, flags);
         else
-                ret = try_to_unmap_file(page, 0, migration);
+                ret = try_to_unmap_file(page, flags);
         if (ret != SWAP_MLOCK && !page_mapped(page))
                 ret = SWAP_SUCCESS;
         return ret;
@@ -1240,8 +1238,8 @@ int try_to_munlock(struct page *page)
         VM_BUG_ON(!PageLocked(page) || PageLRU(page));
 
         if (PageAnon(page))
-                return try_to_unmap_anon(page, 1, 0);
+                return try_to_unmap_anon(page, TTU_MUNLOCK);
         else
-                return try_to_unmap_file(page, 1, 0);
+                return try_to_unmap_file(page, TTU_MUNLOCK);
 }
 
diff --git a/mm/shmem.c b/mm/shmem.c
index d713239ce2ce..356dd99566ec 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -49,7 +49,6 @@ static struct vfsmount *shm_mnt;
 #include <linux/backing-dev.h>
 #include <linux/shmem_fs.h>
 #include <linux/writeback.h>
-#include <linux/vfs.h>
 #include <linux/blkdev.h>
 #include <linux/security.h>
 #include <linux/swapops.h>
@@ -219,7 +218,7 @@ static const struct file_operations shmem_file_operations;
 static const struct inode_operations shmem_inode_operations;
 static const struct inode_operations shmem_dir_inode_operations;
 static const struct inode_operations shmem_special_inode_operations;
-static struct vm_operations_struct shmem_vm_ops;
+static const struct vm_operations_struct shmem_vm_ops;
 
 static struct backing_dev_info shmem_backing_dev_info  __read_mostly = {
         .ra_pages       = 0,    /* No readahead */
@@ -1047,8 +1046,9 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
          * sync from ever calling shmem_writepage; but a stacking filesystem
          * may use the ->writepage of its underlying filesystem, in which case
          * tmpfs should write out to swap only in response to memory pressure,
-         * and not for pdflush or sync.  However, in those cases, we do still
-         * want to check if there's a redundant swappage to be discarded.
+         * and not for the writeback threads or sync.  However, in those cases,
+         * we do still want to check if there's a redundant swappage to be
+         * discarded.
          */
         if (wbc->for_reclaim)
                 swap = get_swap_page();
@@ -1097,6 +1097,10 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
         shmem_swp_unmap(entry);
 unlock:
         spin_unlock(&info->lock);
+        /*
+         * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+         * clear SWAP_HAS_CACHE flag.
+         */
         swapcache_free(swap, NULL);
 redirty:
         set_page_dirty(page);
@@ -1630,8 +1634,8 @@ shmem_write_end(struct file *file, struct address_space *mapping,
         if (pos + copied > inode->i_size)
                 i_size_write(inode, pos + copied);
 
-        unlock_page(page);
         set_page_dirty(page);
+        unlock_page(page);
         page_cache_release(page);
 
         return copied;
@@ -1968,13 +1972,13 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
                         iput(inode);
                         return error;
                 }
-                unlock_page(page);
                 inode->i_mapping->a_ops = &shmem_aops;
                 inode->i_op = &shmem_symlink_inode_operations;
                 kaddr = kmap_atomic(page, KM_USER0);
                 memcpy(kaddr, symname, len);
                 kunmap_atomic(kaddr, KM_USER0);
                 set_page_dirty(page);
+                unlock_page(page);
                 page_cache_release(page);
         }
         if (dir->i_mode & S_ISGID)
@@ -2298,8 +2302,7 @@ static void shmem_put_super(struct super_block *sb)
         sb->s_fs_info = NULL;
 }
 
-static int shmem_fill_super(struct super_block *sb,
-                            void *data, int silent)
+int shmem_fill_super(struct super_block *sb, void *data, int silent)
 {
         struct inode *inode;
         struct dentry *root;
@@ -2307,17 +2310,14 @@ static int shmem_fill_super(struct super_block *sb,
         int err = -ENOMEM;
 
         /* Round up to L1_CACHE_BYTES to resist false sharing */
-        sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info),
+        sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info),
                                 L1_CACHE_BYTES), GFP_KERNEL);
         if (!sbinfo)
                 return -ENOMEM;
 
-        sbinfo->max_blocks = 0;
-        sbinfo->max_inodes = 0;
         sbinfo->mode = S_IRWXUGO | S_ISVTX;
         sbinfo->uid = current_fsuid();
         sbinfo->gid = current_fsgid();
-        sbinfo->mpol = NULL;
         sb->s_fs_info = sbinfo;
 
 #ifdef CONFIG_TMPFS
@@ -2421,6 +2421,7 @@ static const struct address_space_operations shmem_aops = {
         .write_end      = shmem_write_end,
 #endif
         .migratepage    = migrate_page,
+        .error_remove_page = generic_error_remove_page,
 };
 
 static const struct file_operations shmem_file_operations = {
@@ -2446,7 +2447,7 @@ static const struct inode_operations shmem_inode_operations = {
         .getxattr       = generic_getxattr,
         .listxattr      = generic_listxattr,
         .removexattr    = generic_removexattr,
-        .permission     = shmem_permission,
+        .check_acl      = shmem_check_acl,
 #endif
 
 };
@@ -2469,7 +2470,7 @@ static const struct inode_operations shmem_dir_inode_operations = {
         .getxattr       = generic_getxattr,
         .listxattr      = generic_listxattr,
         .removexattr    = generic_removexattr,
-        .permission     = shmem_permission,
+        .check_acl      = shmem_check_acl,
 #endif
 };
 
@@ -2480,7 +2481,7 @@ static const struct inode_operations shmem_special_inode_operations = {
         .getxattr       = generic_getxattr,
         .listxattr      = generic_listxattr,
         .removexattr    = generic_removexattr,
-        .permission     = shmem_permission,
+        .check_acl      = shmem_check_acl,
 #endif
 };
 
@@ -2497,7 +2498,7 @@ static const struct super_operations shmem_ops = {
         .put_super      = shmem_put_super,
 };
 
-static struct vm_operations_struct shmem_vm_ops = {
+static const struct vm_operations_struct shmem_vm_ops = {
         .fault          = shmem_fault,
 #ifdef CONFIG_NUMA
         .set_policy     = shmem_set_policy,
@@ -2519,7 +2520,7 @@ static struct file_system_type tmpfs_fs_type = {
         .kill_sb        = kill_litter_super,
 };
 
-static int __init init_tmpfs(void)
+int __init init_tmpfs(void)
 {
         int error;
 
@@ -2576,7 +2577,7 @@ static struct file_system_type tmpfs_fs_type = {
         .kill_sb        = kill_litter_super,
 };
 
-static int __init init_tmpfs(void)
+int __init init_tmpfs(void)
 {
         BUG_ON(register_filesystem(&tmpfs_fs_type) != 0);
 
@@ -2591,6 +2592,11 @@ int shmem_unuse(swp_entry_t entry, struct page *page)
         return 0;
 }
 
+int shmem_lock(struct file *file, int lock, struct user_struct *user)
+{
+        return 0;
+}
+
 #define shmem_vm_ops                            generic_file_vm_ops
 #define shmem_file_operations                   ramfs_file_operations
 #define shmem_get_inode(sb, mode, dev, flags)   ramfs_get_inode(sb, mode, dev)
@@ -2687,5 +2693,3 @@ int shmem_zero_setup(struct vm_area_struct *vma)
         vma->vm_ops = &shmem_vm_ops;
         return 0;
 }
-
-module_init(init_tmpfs)
diff --git a/mm/shmem_acl.c b/mm/shmem_acl.c
index 606a8e757a42..df2c87fdae50 100644
--- a/mm/shmem_acl.c
+++ b/mm/shmem_acl.c
@@ -157,7 +157,7 @@ shmem_acl_init(struct inode *inode, struct inode *dir)
 /**
  * shmem_check_acl  -  check_acl() callback for generic_permission()
  */
-static int
+int
 shmem_check_acl(struct inode *inode, int mask)
 {
         struct posix_acl *acl = shmem_get_acl(inode, ACL_TYPE_ACCESS);
@@ -169,12 +169,3 @@ shmem_check_acl(struct inode *inode, int mask)
         }
         return -EAGAIN;
 }
-
-/**
- * shmem_permission  -  permission() inode operation
- */
-int
-shmem_permission(struct inode *inode, int mask)
-{
-        return generic_permission(inode, mask, shmem_check_acl);
-}
diff --git a/mm/slab.c b/mm/slab.c
index 7b5d4deacfcd..7dfa481c96ba 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1384,7 +1384,7 @@ void __init kmem_cache_init(void)
          * Fragmentation resistance on low memory - only use bigger
          * page orders on machines with more than 32MB of memory.
          */
-        if (num_physpages > (32 << 20) >> PAGE_SHIFT)
+        if (totalram_pages > (32 << 20) >> PAGE_SHIFT)
                 slab_break_gfp_order = BREAK_GFP_ORDER_HI;
 
         /* Bootstrap is tricky, because several objects are allocated
diff --git a/mm/slob.c b/mm/slob.c
index 9641da3d5e58..837ebd64cc34 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -692,3 +692,8 @@ void __init kmem_cache_init(void)
 {
         slob_ready = 1;
 }
+
+void __init kmem_cache_init_late(void)
+{
+        /* Nothing to do */
+}
diff --git a/mm/slub.c b/mm/slub.c
index b6276753626e..4996fc719552 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -141,6 +141,13 @@
                                 SLAB_POISON | SLAB_STORE_USER)
 
 /*
+ * Debugging flags that require metadata to be stored in the slab.  These get
+ * disabled when slub_debug=O is used and a cache's min order increases with
+ * metadata.
+ */
+#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
+
+/*
  * Set of flags that will prevent slab merging
  */
 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
@@ -325,6 +332,7 @@ static int slub_debug;
 #endif
 
 static char *slub_debug_slabs;
+static int disable_higher_order_debug;
 
 /*
  * Object debugging
@@ -646,7 +654,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page)
         slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
         print_section("Padding", end - remainder, remainder);
 
-        restore_bytes(s, "slab padding", POISON_INUSE, start, end);
+        restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
         return 0;
 }
 
@@ -976,6 +984,15 @@ static int __init setup_slub_debug(char *str)
                  */
                 goto check_slabs;
 
+        if (tolower(*str) == 'o') {
+                /*
+                 * Avoid enabling debugging on caches if its minimum order
+                 * would increase as a result.
+                 */
+                disable_higher_order_debug = 1;
+                goto out;
+        }
+
         slub_debug = 0;
         if (*str == '-')
                 /*
@@ -1026,8 +1043,8 @@ static unsigned long kmem_cache_flags(unsigned long objsize,
          * Enable debugging if selected on the kernel commandline.
          */
         if (slub_debug && (!slub_debug_slabs ||
-            strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0))
-                        flags |= slub_debug;
+                !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
+                flags |= slub_debug;
 
         return flags;
 }
@@ -1054,6 +1071,8 @@ static inline unsigned long kmem_cache_flags(unsigned long objsize,
 }
 #define slub_debug 0
 
+#define disable_higher_order_debug 0
+
 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
                                                         { return 0; }
 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
@@ -1109,8 +1128,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
         }
 
         if (kmemcheck_enabled
-                && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS)))
-        {
+                && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
                 int pages = 1 << oo_order(oo);
 
                 kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
@@ -1560,6 +1578,10 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
                 "default order: %d, min order: %d\n", s->name, s->objsize,
                 s->size, oo_order(s->oo), oo_order(s->min));
 
+        if (oo_order(s->min) > get_order(s->objsize))
+                printk(KERN_WARNING "  %s debugging increased min order, use "
+                       "slub_debug=O to disable.\n", s->name);
+
         for_each_online_node(node) {
                 struct kmem_cache_node *n = get_node(s, node);
                 unsigned long nr_slabs;
@@ -2001,7 +2023,7 @@ static inline int calculate_order(int size)
                                 return order;
                         fraction /= 2;
                 }
-                min_objects --;
+                min_objects--;
         }
 
         /*
@@ -2091,8 +2113,8 @@ init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
  */
 #define NR_KMEM_CACHE_CPU 100
 
-static DEFINE_PER_CPU(struct kmem_cache_cpu,
-                                kmem_cache_cpu)[NR_KMEM_CACHE_CPU];
+static DEFINE_PER_CPU(struct kmem_cache_cpu [NR_KMEM_CACHE_CPU],
+                      kmem_cache_cpu);
 
 static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free);
 static DECLARE_BITMAP(kmem_cach_cpu_free_init_once, CONFIG_NR_CPUS);
@@ -2400,6 +2422,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
          * on bootup.
          */
         align = calculate_alignment(flags, align, s->objsize);
+        s->align = align;
 
         /*
          * SLUB stores one object immediately after another beginning from
@@ -2452,6 +2475,18 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
 
         if (!calculate_sizes(s, -1))
                 goto error;
+        if (disable_higher_order_debug) {
+                /*
+                 * Disable debugging flags that store metadata if the min slab
+                 * order increased.
+                 */
+                if (get_order(s->size) > get_order(s->objsize)) {
+                        s->flags &= ~DEBUG_METADATA_FLAGS;
+                        s->offset = 0;
+                        if (!calculate_sizes(s, -1))
+                                goto error;
+                }
+        }
 
         /*
          * The larger the object size is, the more pages we want on the partial
@@ -2790,6 +2825,11 @@ static s8 size_index[24] = {
         2       /* 192 */
 };
 
+static inline int size_index_elem(size_t bytes)
+{
+        return (bytes - 1) / 8;
+}
+
 static struct kmem_cache *get_slab(size_t size, gfp_t flags)
 {
         int index;
@@ -2798,7 +2838,7 @@ static struct kmem_cache *get_slab(size_t size, gfp_t flags)
                 if (!size)
                         return ZERO_SIZE_PTR;
 
-                index = size_index[(size - 1) / 8];
+                index = size_index[size_index_elem(size)];
         } else
                 index = fls(size - 1);
 
@@ -3156,10 +3196,12 @@ void __init kmem_cache_init(void)
         slab_state = PARTIAL;
 
         /* Caches that are not of the two-to-the-power-of size */
-        if (KMALLOC_MIN_SIZE <= 64) {
+        if (KMALLOC_MIN_SIZE <= 32) {
                 create_kmalloc_cache(&kmalloc_caches[1],
                                 "kmalloc-96", 96, GFP_NOWAIT);
                 caches++;
+        }
+        if (KMALLOC_MIN_SIZE <= 64) {
                 create_kmalloc_cache(&kmalloc_caches[2],
                                 "kmalloc-192", 192, GFP_NOWAIT);
                 caches++;
@@ -3186,17 +3228,28 @@ void __init kmem_cache_init(void)
         BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
                 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
 
-        for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
-                size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
+        for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
+                int elem = size_index_elem(i);
+                if (elem >= ARRAY_SIZE(size_index))
+                        break;
+                size_index[elem] = KMALLOC_SHIFT_LOW;
+        }
 
-        if (KMALLOC_MIN_SIZE == 128) {
+        if (KMALLOC_MIN_SIZE == 64) {
+                /*
+                 * The 96 byte size cache is not used if the alignment
+                 * is 64 byte.
+                 */
+                for (i = 64 + 8; i <= 96; i += 8)
+                        size_index[size_index_elem(i)] = 7;
+        } else if (KMALLOC_MIN_SIZE == 128) {
                 /*
                  * The 192 byte sized cache is not used if the alignment
                  * is 128 byte. Redirect kmalloc to use the 256 byte cache
                  * instead.
                  */
                 for (i = 128 + 8; i <= 192; i += 8)
-                        size_index[(i - 1) / 8] = 8;
+                        size_index[size_index_elem(i)] = 8;
         }
 
         slab_state = UP;
@@ -3292,6 +3345,9 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
 {
         struct kmem_cache *s;
 
+        if (WARN_ON(!name))
+                return NULL;
+
         down_write(&slub_lock);
         s = find_mergeable(size, align, flags, name, ctor);
         if (s) {
@@ -4543,8 +4599,11 @@ static int sysfs_slab_add(struct kmem_cache *s)
         }
 
         err = sysfs_create_group(&s->kobj, &slab_attr_group);
-        if (err)
+        if (err) {
+                kobject_del(&s->kobj);
+                kobject_put(&s->kobj);
                 return err;
+        }
         kobject_uevent(&s->kobj, KOBJ_ADD);
         if (!unmergeable) {
                 /* Setup first alias */
@@ -4726,7 +4785,7 @@ static const struct file_operations proc_slabinfo_operations = {
 
 static int __init slab_proc_init(void)
 {
-        proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
+        proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
         return 0;
 }
 module_init(slab_proc_init);
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index a13ea6401ae7..d9714bdcb4a3 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -48,8 +48,14 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
 {
         /* If the main allocator is up use that, fallback to bootmem. */
         if (slab_is_available()) {
-                struct page *page = alloc_pages_node(node,
+                struct page *page;
+
+                if (node_state(node, N_HIGH_MEMORY))
+                        page = alloc_pages_node(node,
                                 GFP_KERNEL | __GFP_ZERO, get_order(size));
+                else
+                        page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
+                                get_order(size));
                 if (page)
                         return page_address(page);
                 return NULL;
diff --git a/mm/sparse.c b/mm/sparse.c
index da432d9f0ae8..6ce4aab69e99 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -62,9 +62,12 @@ static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
         unsigned long array_size = SECTIONS_PER_ROOT *
                                    sizeof(struct mem_section);
 
-        if (slab_is_available())
-                section = kmalloc_node(array_size, GFP_KERNEL, nid);
-        else
+        if (slab_is_available()) {
+                if (node_state(nid, N_HIGH_MEMORY))
+                        section = kmalloc_node(array_size, GFP_KERNEL, nid);
+                else
+                        section = kmalloc(array_size, GFP_KERNEL);
+        } else
                 section = alloc_bootmem_node(NODE_DATA(nid), array_size);
 
         if (section)
diff --git a/mm/swap.c b/mm/swap.c
index cb29ae5d33ab..308e57d8d7ed 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -118,7 +118,7 @@ static void pagevec_move_tail(struct pagevec *pvec)
                         spin_lock(&zone->lru_lock);
                 }
                 if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
-                        int lru = page_is_file_cache(page);
+                        int lru = page_lru_base_type(page);
                         list_move_tail(&page->lru, &zone->lru[lru].list);
                         pgmoved++;
                 }
@@ -181,7 +181,7 @@ void activate_page(struct page *page)
         spin_lock_irq(&zone->lru_lock);
         if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
                 int file = page_is_file_cache(page);
-                int lru = LRU_BASE + file;
+                int lru = page_lru_base_type(page);
                 del_page_from_lru_list(zone, page, lru);
 
                 SetPageActive(page);
@@ -189,7 +189,7 @@ void activate_page(struct page *page)
                 add_page_to_lru_list(zone, page, lru);
                 __count_vm_event(PGACTIVATE);
 
-                update_page_reclaim_stat(zone, page, !!file, 1);
+                update_page_reclaim_stat(zone, page, file, 1);
         }
         spin_unlock_irq(&zone->lru_lock);
 }
@@ -496,7 +496,7 @@ EXPORT_SYMBOL(pagevec_lookup_tag);
  */
 void __init swap_setup(void)
 {
-        unsigned long megs = num_physpages >> (20 - PAGE_SHIFT);
+        unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT);
 
 #ifdef CONFIG_SWAP
         bdi_init(swapper_space.backing_dev_info);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 42cd38eba79f..6d1daeb1cb4a 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -34,6 +34,7 @@ static const struct address_space_operations swap_aops = {
 };
 
 static struct backing_dev_info swap_backing_dev_info = {
+        .name           = "swap",
         .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED,
         .unplug_io_fn   = swap_unplug_io_fn,
 };
@@ -66,10 +67,10 @@ void show_swap_cache_info(void)
 }
 
 /*
- * add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
+ * __add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
  * but sets SwapCache flag and private instead of mapping and index.
  */
-int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
+static int __add_to_swap_cache(struct page *page, swp_entry_t entry)
 {
         int error;
 
@@ -77,28 +78,43 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
         VM_BUG_ON(PageSwapCache(page));
         VM_BUG_ON(!PageSwapBacked(page));
 
+        page_cache_get(page);
+        SetPageSwapCache(page);
+        set_page_private(page, entry.val);
+
+        spin_lock_irq(&swapper_space.tree_lock);
+        error = radix_tree_insert(&swapper_space.page_tree, entry.val, page);
+        if (likely(!error)) {
+                total_swapcache_pages++;
+                __inc_zone_page_state(page, NR_FILE_PAGES);
+                INC_CACHE_INFO(add_total);
+        }
+        spin_unlock_irq(&swapper_space.tree_lock);
+
+        if (unlikely(error)) {
+                /*
+                 * Only the context which have set SWAP_HAS_CACHE flag
+                 * would call add_to_swap_cache().
+                 * So add_to_swap_cache() doesn't returns -EEXIST.
+                 */
+                VM_BUG_ON(error == -EEXIST);
+                set_page_private(page, 0UL);
+                ClearPageSwapCache(page);
+                page_cache_release(page);
+        }
+
+        return error;
+}
+
+
+int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
+{
+        int error;
+
         error = radix_tree_preload(gfp_mask);
         if (!error) {
-                page_cache_get(page);
-                SetPageSwapCache(page);
-                set_page_private(page, entry.val);
-
-                spin_lock_irq(&swapper_space.tree_lock);
-                error = radix_tree_insert(&swapper_space.page_tree,
-                                                entry.val, page);
-                if (likely(!error)) {
-                        total_swapcache_pages++;
-                        __inc_zone_page_state(page, NR_FILE_PAGES);
-                        INC_CACHE_INFO(add_total);
-                }
-                spin_unlock_irq(&swapper_space.tree_lock);
+                error = __add_to_swap_cache(page, entry);
                 radix_tree_preload_end();
-
-                if (unlikely(error)) {
-                        set_page_private(page, 0UL);
-                        ClearPageSwapCache(page);
-                        page_cache_release(page);
-                }
         }
         return error;
 }
@@ -136,38 +152,34 @@ int add_to_swap(struct page *page)
         VM_BUG_ON(!PageLocked(page));
         VM_BUG_ON(!PageUptodate(page));
 
-        for (;;) {
-                entry = get_swap_page();
-                if (!entry.val)
-                        return 0;
+        entry = get_swap_page();
+        if (!entry.val)
+                return 0;
 
+        /*
+         * Radix-tree node allocations from PF_MEMALLOC contexts could
+         * completely exhaust the page allocator. __GFP_NOMEMALLOC
+         * stops emergency reserves from being allocated.
+         *
+         * TODO: this could cause a theoretical memory reclaim
+         * deadlock in the swap out path.
+         */
+        /*
+         * Add it to the swap cache and mark it dirty
+         */
+        err = add_to_swap_cache(page, entry,
+                        __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
+
+        if (!err) {     /* Success */
+                SetPageDirty(page);
+                return 1;
+        } else {        /* -ENOMEM radix-tree allocation failure */
                 /*
-                 * Radix-tree node allocations from PF_MEMALLOC contexts could
-                 * completely exhaust the page allocator. __GFP_NOMEMALLOC
-                 * stops emergency reserves from being allocated.
-                 *
-                 * TODO: this could cause a theoretical memory reclaim
-                 * deadlock in the swap out path.
-                 */
-                /*
-                 * Add it to the swap cache and mark it dirty
+                 * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+                 * clear SWAP_HAS_CACHE flag.
                  */
-                err = add_to_swap_cache(page, entry,
-                                __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
-
-                switch (err) {
-                case 0:                         /* Success */
-                        SetPageDirty(page);
-                        return 1;
-                case -EEXIST:
-                        /* Raced with "speculative" read_swap_cache_async */
-                        swapcache_free(entry, NULL);
-                        continue;
-                default:
-                        /* -ENOMEM radix-tree allocation failure */
-                        swapcache_free(entry, NULL);
-                        return 0;
-                }
+                swapcache_free(entry, NULL);
+                return 0;
         }
 }
 
@@ -289,26 +301,31 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
                 }
 
                 /*
+                 * call radix_tree_preload() while we can wait.
+                 */
+                err = radix_tree_preload(gfp_mask & GFP_KERNEL);
+                if (err)
+                        break;
+
+                /*
                  * Swap entry may have been freed since our caller observed it.
                  */
                 err = swapcache_prepare(entry);
-                if (err == -EEXIST) /* seems racy */
+                if (err == -EEXIST) {   /* seems racy */
+                        radix_tree_preload_end();
                         continue;
-                if (err)           /* swp entry is obsolete ? */
+                }
+                if (err) {              /* swp entry is obsolete ? */
+                        radix_tree_preload_end();
                         break;
+                }
 
-                /*
-                 * Associate the page with swap entry in the swap cache.
-                 * May fail (-EEXIST) if there is already a page associated
-                 * with this entry in the swap cache: added by a racing
-                 * read_swap_cache_async, or add_to_swap or shmem_writepage
-                 * re-using the just freed swap entry for an existing page.
-                 * May fail (-ENOMEM) if radix-tree node allocation failed.
-                 */
+                /* May fail (-ENOMEM) if radix-tree node allocation failed. */
                 __set_page_locked(new_page);
                 SetPageSwapBacked(new_page);
-                err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL);
+                err = __add_to_swap_cache(new_page, entry);
                 if (likely(!err)) {
+                        radix_tree_preload_end();
                         /*
                          * Initiate read into locked page and return.
                          */
@@ -316,8 +333,13 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
                         swap_readpage(new_page);
                         return new_page;
                 }
+                radix_tree_preload_end();
                 ClearPageSwapBacked(new_page);
                 __clear_page_locked(new_page);
+                /*
+                 * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+                 * clear SWAP_HAS_CACHE flag.
+                 */
                 swapcache_free(entry, NULL);
         } while (err != -ENOMEM);
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 8ffdc0d23c53..a1bc6b9af9a2 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -161,7 +161,8 @@ static int discard_swap(struct swap_info_struct *si)
                 }
 
                 err = blkdev_issue_discard(si->bdev, start_block,
-                                                nr_blocks, GFP_KERNEL);
+                                                nr_blocks, GFP_KERNEL,
+                                                DISCARD_FL_BARRIER);
                 if (err)
                         break;
 
@@ -200,7 +201,8 @@ static void discard_swap_cluster(struct swap_info_struct *si,
                         start_block <<= PAGE_SHIFT - 9;
                         nr_blocks <<= PAGE_SHIFT - 9;
                         if (blkdev_issue_discard(si->bdev, start_block,
-                                                        nr_blocks, GFP_NOIO))
+                                                        nr_blocks, GFP_NOIO,
+                                                        DISCARD_FL_BARRIER))
                                 break;
                 }
 
@@ -697,7 +699,7 @@ int free_swap_and_cache(swp_entry_t entry)
         struct swap_info_struct *p;
         struct page *page = NULL;
 
-        if (is_migration_entry(entry))
+        if (non_swap_entry(entry))
                 return 1;
 
         p = swap_info_get(entry);
@@ -1573,9 +1575,9 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
         p->flags &= ~SWP_WRITEOK;
         spin_unlock(&swap_lock);
 
-        current->flags |= PF_SWAPOFF;
+        current->flags |= PF_OOM_ORIGIN;
         err = try_to_unuse(type);
-        current->flags &= ~PF_SWAPOFF;
+        current->flags &= ~PF_OOM_ORIGIN;
 
         if (err) {
                 /* re-insert swap space back into swap_list */
@@ -1972,12 +1974,14 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
                 goto bad_swap;
         }
 
-        if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
-                p->flags |= SWP_SOLIDSTATE;
-                p->cluster_next = 1 + (random32() % p->highest_bit);
+        if (p->bdev) {
+                if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
+                        p->flags |= SWP_SOLIDSTATE;
+                        p->cluster_next = 1 + (random32() % p->highest_bit);
+                }
+                if (discard_swap(p) == 0)
+                        p->flags |= SWP_DISCARDABLE;
         }
-        if (discard_swap(p) == 0)
-                p->flags |= SWP_DISCARDABLE;
 
         mutex_lock(&swapon_mutex);
         spin_lock(&swap_lock);
@@ -2083,7 +2087,7 @@ static int __swap_duplicate(swp_entry_t entry, bool cache)
         int count;
         bool has_cache;
 
-        if (is_migration_entry(entry))
+        if (non_swap_entry(entry))
                 return -EINVAL;
 
         type = swp_type(entry);
diff --git a/mm/truncate.c b/mm/truncate.c
index ccc3ecf7cb98..450cebdabfc0 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -93,11 +93,11 @@ EXPORT_SYMBOL(cancel_dirty_page);
  * its lock, b) when a concurrent invalidate_mapping_pages got there first and
  * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
  */
-static void
+static int
 truncate_complete_page(struct address_space *mapping, struct page *page)
 {
         if (page->mapping != mapping)
-                return;
+                return -EIO;
 
         if (page_has_private(page))
                 do_invalidatepage(page, 0);
@@ -108,6 +108,7 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
         remove_from_page_cache(page);
         ClearPageMappedToDisk(page);
         page_cache_release(page);       /* pagecache ref */
+        return 0;
 }
 
 /*
@@ -135,6 +136,51 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
         return ret;
 }
 
+int truncate_inode_page(struct address_space *mapping, struct page *page)
+{
+        if (page_mapped(page)) {
+                unmap_mapping_range(mapping,
+                                   (loff_t)page->index << PAGE_CACHE_SHIFT,
+                                   PAGE_CACHE_SIZE, 0);
+        }
+        return truncate_complete_page(mapping, page);
+}
+
+/*
+ * Used to get rid of pages on hardware memory corruption.
+ */
+int generic_error_remove_page(struct address_space *mapping, struct page *page)
+{
+        if (!mapping)
+                return -EINVAL;
+        /*
+         * Only punch for normal data pages for now.
+         * Handling other types like directories would need more auditing.
+         */
+        if (!S_ISREG(mapping->host->i_mode))
+                return -EIO;
+        return truncate_inode_page(mapping, page);
+}
+EXPORT_SYMBOL(generic_error_remove_page);
+
+/*
+ * Safely invalidate one page from its pagecache mapping.
+ * It only drops clean, unused pages. The page must be locked.
+ *
+ * Returns 1 if the page is successfully invalidated, otherwise 0.
+ */
+int invalidate_inode_page(struct page *page)
+{
+        struct address_space *mapping = page_mapping(page);
+        if (!mapping)
+                return 0;
+        if (PageDirty(page) || PageWriteback(page))
+                return 0;
+        if (page_mapped(page))
+                return 0;
+        return invalidate_complete_page(mapping, page);
+}
+
 /**
  * truncate_inode_pages - truncate range of pages specified by start & end byte offsets
  * @mapping: mapping to truncate
@@ -196,12 +242,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                                 unlock_page(page);
                                 continue;
                         }
-                        if (page_mapped(page)) {
-                                unmap_mapping_range(mapping,
-                                  (loff_t)page_index<<PAGE_CACHE_SHIFT,
-                                  PAGE_CACHE_SIZE, 0);
-                        }
-                        truncate_complete_page(mapping, page);
+                        truncate_inode_page(mapping, page);
                         unlock_page(page);
                 }
                 pagevec_release(&pvec);
@@ -238,15 +279,10 @@ void truncate_inode_pages_range(struct address_space *mapping,
                                 break;
                         lock_page(page);
                         wait_on_page_writeback(page);
-                        if (page_mapped(page)) {
-                                unmap_mapping_range(mapping,
-                                  (loff_t)page->index<<PAGE_CACHE_SHIFT,
-                                  PAGE_CACHE_SIZE, 0);
-                        }
+                        truncate_inode_page(mapping, page);
                         if (page->index > next)
                                 next = page->index;
                         next++;
-                        truncate_complete_page(mapping, page);
                         unlock_page(page);
                 }
                 pagevec_release(&pvec);
@@ -311,12 +347,8 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
                         if (lock_failed)
                                 continue;
 
-                        if (PageDirty(page) || PageWriteback(page))
-                                goto unlock;
-                        if (page_mapped(page))
-                                goto unlock;
-                        ret += invalidate_complete_page(mapping, page);
-unlock:
+                        ret += invalidate_inode_page(page);
+
                         unlock_page(page);
                         if (next > end)
                                 break;
@@ -465,3 +497,67 @@ int invalidate_inode_pages2(struct address_space *mapping)
         return invalidate_inode_pages2_range(mapping, 0, -1);
 }
 EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
+
+/**
+ * truncate_pagecache - unmap and remove pagecache that has been truncated
+ * @inode: inode
+ * @old: old file offset
+ * @new: new file offset
+ *
+ * inode's new i_size must already be written before truncate_pagecache
+ * is called.
+ *
+ * This function should typically be called before the filesystem
+ * releases resources associated with the freed range (eg. deallocates
+ * blocks). This way, pagecache will always stay logically coherent
+ * with on-disk format, and the filesystem would not have to deal with
+ * situations such as writepage being called for a page that has already
+ * had its underlying blocks deallocated.
+ */
+void truncate_pagecache(struct inode *inode, loff_t old, loff_t new)
+{
+        if (new < old) {
+                struct address_space *mapping = inode->i_mapping;
+
+                /*
+                 * unmap_mapping_range is called twice, first simply for
+                 * efficiency so that truncate_inode_pages does fewer
+                 * single-page unmaps.  However after this first call, and
+                 * before truncate_inode_pages finishes, it is possible for
+                 * private pages to be COWed, which remain after
+                 * truncate_inode_pages finishes, hence the second
+                 * unmap_mapping_range call must be made for correctness.
+                 */
+                unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
+                truncate_inode_pages(mapping, new);
+                unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
+        }
+}
+EXPORT_SYMBOL(truncate_pagecache);
+
+/**
+ * vmtruncate - unmap mappings "freed" by truncate() syscall
+ * @inode: inode of the file used
+ * @offset: file offset to start truncating
+ *
+ * NOTE! We have to be ready to update the memory sharing
+ * between the file and the memory map for a potential last
+ * incomplete page.  Ugly, but necessary.
+ */
+int vmtruncate(struct inode *inode, loff_t offset)
+{
+        loff_t oldsize;
+        int error;
+
+        error = inode_newsize_ok(inode, offset);
+        if (error)
+                return error;
+        oldsize = inode->i_size;
+        i_size_write(inode, offset);
+        truncate_pagecache(inode, oldsize, offset);
+        if (inode->i_op->truncate)
+                inode->i_op->truncate(inode);
+
+        return error;
+}
+EXPORT_SYMBOL(vmtruncate);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index f8189a4b3e13..0f551a4a44cd 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -12,6 +12,7 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/highmem.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
@@ -25,10 +26,10 @@
 #include <linux/rcupdate.h>
 #include <linux/pfn.h>
 #include <linux/kmemleak.h>
-
 #include <asm/atomic.h>
 #include <asm/uaccess.h>
 #include <asm/tlbflush.h>
+#include <asm/shmparam.h>
 
 
 /*** Page table manipulation functions ***/
@@ -168,11 +169,9 @@ static int vmap_page_range_noflush(unsigned long start, unsigned long end,
                 next = pgd_addr_end(addr, end);
                 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
                 if (err)
-                        break;
+                        return err;
         } while (pgd++, addr = next, addr != end);
 
-        if (unlikely(err))
-                return err;
         return nr;
 }
 
@@ -186,7 +185,7 @@ static int vmap_page_range(unsigned long start, unsigned long end,
         return ret;
 }
 
-static inline int is_vmalloc_or_module_addr(const void *x)
+int is_vmalloc_or_module_addr(const void *x)
 {
         /*
          * ARM, x86-64 and sparc64 put modules in a special place,
@@ -265,6 +264,7 @@ struct vmap_area {
 static DEFINE_SPINLOCK(vmap_area_lock);
 static struct rb_root vmap_area_root = RB_ROOT;
 static LIST_HEAD(vmap_area_list);
+static unsigned long vmap_area_pcpu_hole;
 
 static struct vmap_area *__find_vmap_area(unsigned long addr)
 {
@@ -431,6 +431,15 @@ static void __free_vmap_area(struct vmap_area *va)
         RB_CLEAR_NODE(&va->rb_node);
         list_del_rcu(&va->list);
 
+        /*
+         * Track the highest possible candidate for pcpu area
+         * allocation.  Areas outside of vmalloc area can be returned
+         * here too, consider only end addresses which fall inside
+         * vmalloc area proper.
+         */
+        if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
+                vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
+
         call_rcu(&va->rcu_head, rcu_free_va);
 }
 
@@ -1038,6 +1047,9 @@ void __init vmalloc_init(void)
                 va->va_end = va->va_start + tmp->size;
                 __insert_vmap_area(va);
         }
+
+        vmap_area_pcpu_hole = VMALLOC_END;
+
         vmap_initialized = true;
 }
 
@@ -1122,14 +1134,34 @@ EXPORT_SYMBOL_GPL(map_vm_area);
 DEFINE_RWLOCK(vmlist_lock);
 struct vm_struct *vmlist;
 
+static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+                              unsigned long flags, void *caller)
+{
+        struct vm_struct *tmp, **p;
+
+        vm->flags = flags;
+        vm->addr = (void *)va->va_start;
+        vm->size = va->va_end - va->va_start;
+        vm->caller = caller;
+        va->private = vm;
+        va->flags |= VM_VM_AREA;
+
+        write_lock(&vmlist_lock);
+        for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+                if (tmp->addr >= vm->addr)
+                        break;
+        }
+        vm->next = *p;
+        *p = vm;
+        write_unlock(&vmlist_lock);
+}
+
 static struct vm_struct *__get_vm_area_node(unsigned long size,
-                unsigned long flags, unsigned long start, unsigned long end,
-                int node, gfp_t gfp_mask, void *caller)
+                unsigned long align, unsigned long flags, unsigned long start,
+                unsigned long end, int node, gfp_t gfp_mask, void *caller)
 {
         static struct vmap_area *va;
         struct vm_struct *area;
-        struct vm_struct *tmp, **p;
-        unsigned long align = 1;
 
         BUG_ON(in_interrupt());
         if (flags & VM_IOREMAP) {
@@ -1147,7 +1179,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
         if (unlikely(!size))
                 return NULL;
 
-        area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
+        area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
         if (unlikely(!area))
                 return NULL;
 
@@ -1162,32 +1194,14 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
                 return NULL;
         }
 
-        area->flags = flags;
-        area->addr = (void *)va->va_start;
-        area->size = size;
-        area->pages = NULL;
-        area->nr_pages = 0;
-        area->phys_addr = 0;
-        area->caller = caller;
-        va->private = area;
-        va->flags |= VM_VM_AREA;
-
-        write_lock(&vmlist_lock);
-        for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
-                if (tmp->addr >= area->addr)
-                        break;
-        }
-        area->next = *p;
-        *p = area;
-        write_unlock(&vmlist_lock);
-
+        insert_vmalloc_vm(area, va, flags, caller);
         return area;
 }
 
 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
                                 unsigned long start, unsigned long end)
 {
-        return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
+        return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
                                                 __builtin_return_address(0));
 }
 EXPORT_SYMBOL_GPL(__get_vm_area);
@@ -1196,7 +1210,7 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
                                        unsigned long start, unsigned long end,
                                        void *caller)
 {
-        return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
+        return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
                                   caller);
 }
 
@@ -1211,22 +1225,22 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
  */
 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
 {
-        return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+        return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
                                 -1, GFP_KERNEL, __builtin_return_address(0));
 }
 
 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
                                 void *caller)
 {
-        return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+        return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
                                                 -1, GFP_KERNEL, caller);
 }
 
 struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
                                    int node, gfp_t gfp_mask)
 {
-        return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,
-                                  gfp_mask, __builtin_return_address(0));
+        return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
+                                  node, gfp_mask, __builtin_return_address(0));
 }
 
 static struct vm_struct *find_vm_area(const void *addr)
@@ -1256,17 +1270,21 @@ struct vm_struct *remove_vm_area(const void *addr)
         if (va && va->flags & VM_VM_AREA) {
                 struct vm_struct *vm = va->private;
                 struct vm_struct *tmp, **p;
-
-                vmap_debug_free_range(va->va_start, va->va_end);
-                free_unmap_vmap_area(va);
-                vm->size -= PAGE_SIZE;
-
+                /*
+                 * remove from list and disallow access to this vm_struct
+                 * before unmap. (address range confliction is maintained by
+                 * vmap.)
+                 */
                 write_lock(&vmlist_lock);
                 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
                         ;
                 *p = tmp->next;
                 write_unlock(&vmlist_lock);
 
+                vmap_debug_free_range(va->va_start, va->va_end);
+                free_unmap_vmap_area(va);
+                vm->size -= PAGE_SIZE;
+
                 return vm;
         }
         return NULL;
@@ -1368,7 +1386,7 @@ void *vmap(struct page **pages, unsigned int count,
 
         might_sleep();
 
-        if (count > num_physpages)
+        if (count > totalram_pages)
                 return NULL;
 
         area = get_vm_area_caller((count << PAGE_SHIFT), flags,
@@ -1385,7 +1403,8 @@ void *vmap(struct page **pages, unsigned int count,
 }
 EXPORT_SYMBOL(vmap);
 
-static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+                            gfp_t gfp_mask, pgprot_t prot,
                             int node, void *caller);
 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
                                  pgprot_t prot, int node, void *caller)
@@ -1399,7 +1418,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
         area->nr_pages = nr_pages;
         /* Please note that the recursion is strictly bounded. */
         if (array_size > PAGE_SIZE) {
-                pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,
+                pages = __vmalloc_node(array_size, 1, gfp_mask | __GFP_ZERO,
                                 PAGE_KERNEL, node, caller);
                 area->flags |= VM_VPAGES;
         } else {
@@ -1458,6 +1477,7 @@ void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
 /**
  *      __vmalloc_node  -  allocate virtually contiguous memory
  *      @size:          allocation size
+ *      @align:         desired alignment
  *      @gfp_mask:      flags for the page level allocator
  *      @prot:          protection mask for the allocated pages
  *      @node:          node to use for allocation or -1
@@ -1467,19 +1487,20 @@ void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
  *      allocator with @gfp_mask flags.  Map them into contiguous
  *      kernel virtual space, using a pagetable protection of @prot.
  */
-static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
-                                                int node, void *caller)
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+                            gfp_t gfp_mask, pgprot_t prot,
+                            int node, void *caller)
 {
         struct vm_struct *area;
         void *addr;
         unsigned long real_size = size;
 
         size = PAGE_ALIGN(size);
-        if (!size || (size >> PAGE_SHIFT) > num_physpages)
+        if (!size || (size >> PAGE_SHIFT) > totalram_pages)
                 return NULL;
 
-        area = __get_vm_area_node(size, VM_ALLOC, VMALLOC_START, VMALLOC_END,
-                                                node, gfp_mask, caller);
+        area = __get_vm_area_node(size, align, VM_ALLOC, VMALLOC_START,
+                                  VMALLOC_END, node, gfp_mask, caller);
 
         if (!area)
                 return NULL;
@@ -1498,7 +1519,7 @@ static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
 
 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
 {
-        return __vmalloc_node(size, gfp_mask, prot, -1,
+        return __vmalloc_node(size, 1, gfp_mask, prot, -1,
                                 __builtin_return_address(0));
 }
 EXPORT_SYMBOL(__vmalloc);
@@ -1514,7 +1535,7 @@ EXPORT_SYMBOL(__vmalloc);
  */
 void *vmalloc(unsigned long size)
 {
-        return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+        return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
                                         -1, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc);
@@ -1531,7 +1552,8 @@ void *vmalloc_user(unsigned long size)
         struct vm_struct *area;
         void *ret;
 
-        ret = __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+        ret = __vmalloc_node(size, SHMLBA,
+                             GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
                              PAGE_KERNEL, -1, __builtin_return_address(0));
         if (ret) {
                 area = find_vm_area(ret);
@@ -1554,7 +1576,7 @@ EXPORT_SYMBOL(vmalloc_user);
  */
 void *vmalloc_node(unsigned long size, int node)
 {
-        return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+        return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
                                         node, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_node);
@@ -1577,7 +1599,7 @@ EXPORT_SYMBOL(vmalloc_node);
 
 void *vmalloc_exec(unsigned long size)
 {
-        return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
+        return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
                               -1, __builtin_return_address(0));
 }
 
@@ -1598,7 +1620,7 @@ void *vmalloc_exec(unsigned long size)
  */
 void *vmalloc_32(unsigned long size)
 {
-        return __vmalloc_node(size, GFP_VMALLOC32, PAGE_KERNEL,
+        return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
                               -1, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_32);
@@ -1615,7 +1637,7 @@ void *vmalloc_32_user(unsigned long size)
         struct vm_struct *area;
         void *ret;
 
-        ret = __vmalloc_node(size, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+        ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
                              -1, __builtin_return_address(0));
         if (ret) {
                 area = find_vm_area(ret);
@@ -1625,10 +1647,120 @@ void *vmalloc_32_user(unsigned long size)
 }
 EXPORT_SYMBOL(vmalloc_32_user);
 
+/*
+ * small helper routine , copy contents to buf from addr.
+ * If the page is not present, fill zero.
+ */
+
+static int aligned_vread(char *buf, char *addr, unsigned long count)
+{
+        struct page *p;
+        int copied = 0;
+
+        while (count) {
+                unsigned long offset, length;
+
+                offset = (unsigned long)addr & ~PAGE_MASK;
+                length = PAGE_SIZE - offset;
+                if (length > count)
+                        length = count;
+                p = vmalloc_to_page(addr);
+                /*
+                 * To do safe access to this _mapped_ area, we need
+                 * lock. But adding lock here means that we need to add
+                 * overhead of vmalloc()/vfree() calles for this _debug_
+                 * interface, rarely used. Instead of that, we'll use
+                 * kmap() and get small overhead in this access function.
+                 */
+                if (p) {
+                        /*
+                         * we can expect USER0 is not used (see vread/vwrite's
+                         * function description)
+                         */
+                        void *map = kmap_atomic(p, KM_USER0);
+                        memcpy(buf, map + offset, length);
+                        kunmap_atomic(map, KM_USER0);
+                } else
+                        memset(buf, 0, length);
+
+                addr += length;
+                buf += length;
+                copied += length;
+                count -= length;
+        }
+        return copied;
+}
+
+static int aligned_vwrite(char *buf, char *addr, unsigned long count)
+{
+        struct page *p;
+        int copied = 0;
+
+        while (count) {
+                unsigned long offset, length;
+
+                offset = (unsigned long)addr & ~PAGE_MASK;
+                length = PAGE_SIZE - offset;
+                if (length > count)
+                        length = count;
+                p = vmalloc_to_page(addr);
+                /*
+                 * To do safe access to this _mapped_ area, we need
+                 * lock. But adding lock here means that we need to add
+                 * overhead of vmalloc()/vfree() calles for this _debug_
+                 * interface, rarely used. Instead of that, we'll use
+                 * kmap() and get small overhead in this access function.
+                 */
+                if (p) {
+                        /*
+                         * we can expect USER0 is not used (see vread/vwrite's
+                         * function description)
+                         */
+                        void *map = kmap_atomic(p, KM_USER0);
+                        memcpy(map + offset, buf, length);
+                        kunmap_atomic(map, KM_USER0);
+                }
+                addr += length;
+                buf += length;
+                copied += length;
+                count -= length;
+        }
+        return copied;
+}
+
+/**
+ *      vread() -  read vmalloc area in a safe way.
+ *      @buf:           buffer for reading data
+ *      @addr:          vm address.
+ *      @count:         number of bytes to be read.
+ *
+ *      Returns # of bytes which addr and buf should be increased.
+ *      (same number to @count). Returns 0 if [addr...addr+count) doesn't
+ *      includes any intersect with alive vmalloc area.
+ *
+ *      This function checks that addr is a valid vmalloc'ed area, and
+ *      copy data from that area to a given buffer. If the given memory range
+ *      of [addr...addr+count) includes some valid address, data is copied to
+ *      proper area of @buf. If there are memory holes, they'll be zero-filled.
+ *      IOREMAP area is treated as memory hole and no copy is done.
+ *
+ *      If [addr...addr+count) doesn't includes any intersects with alive
+ *      vm_struct area, returns 0.
+ *      @buf should be kernel's buffer. Because this function uses KM_USER0,
+ *      the caller should guarantee KM_USER0 is not used.
+ *
+ *      Note: In usual ops, vread() is never necessary because the caller
+ *      should know vmalloc() area is valid and can use memcpy().
+ *      This is for routines which have to access vmalloc area without
+ *      any informaion, as /dev/kmem.
+ *
+ */
+
 long vread(char *buf, char *addr, unsigned long count)
 {
         struct vm_struct *tmp;
         char *vaddr, *buf_start = buf;
+        unsigned long buflen = count;
         unsigned long n;
 
         /* Don't allow overflow */
@@ -1636,7 +1768,7 @@ long vread(char *buf, char *addr, unsigned long count)
                 count = -(unsigned long) addr;
 
         read_lock(&vmlist_lock);
-        for (tmp = vmlist; tmp; tmp = tmp->next) {
+        for (tmp = vmlist; count && tmp; tmp = tmp->next) {
                 vaddr = (char *) tmp->addr;
                 if (addr >= vaddr + tmp->size - PAGE_SIZE)
                         continue;
@@ -1649,32 +1781,72 @@ long vread(char *buf, char *addr, unsigned long count)
                         count--;
                 }
                 n = vaddr + tmp->size - PAGE_SIZE - addr;
-                do {
-                        if (count == 0)
-                                goto finished;
-                        *buf = *addr;
-                        buf++;
-                        addr++;
-                        count--;
-                } while (--n > 0);
+                if (n > count)
+                        n = count;
+                if (!(tmp->flags & VM_IOREMAP))
+                        aligned_vread(buf, addr, n);
+                else /* IOREMAP area is treated as memory hole */
+                        memset(buf, 0, n);
+                buf += n;
+                addr += n;
+                count -= n;
         }
 finished:
         read_unlock(&vmlist_lock);
-        return buf - buf_start;
+
+        if (buf == buf_start)
+                return 0;
+        /* zero-fill memory holes */
+        if (buf != buf_start + buflen)
+                memset(buf, 0, buflen - (buf - buf_start));
+
+        return buflen;
 }
 
+/**
+ *      vwrite() -  write vmalloc area in a safe way.
+ *      @buf:           buffer for source data
+ *      @addr:          vm address.
+ *      @count:         number of bytes to be read.
+ *
+ *      Returns # of bytes which addr and buf should be incresed.
+ *      (same number to @count).
+ *      If [addr...addr+count) doesn't includes any intersect with valid
+ *      vmalloc area, returns 0.
+ *
+ *      This function checks that addr is a valid vmalloc'ed area, and
+ *      copy data from a buffer to the given addr. If specified range of
+ *      [addr...addr+count) includes some valid address, data is copied from
+ *      proper area of @buf. If there are memory holes, no copy to hole.
+ *      IOREMAP area is treated as memory hole and no copy is done.
+ *
+ *      If [addr...addr+count) doesn't includes any intersects with alive
+ *      vm_struct area, returns 0.
+ *      @buf should be kernel's buffer. Because this function uses KM_USER0,
+ *      the caller should guarantee KM_USER0 is not used.
+ *
+ *      Note: In usual ops, vwrite() is never necessary because the caller
+ *      should know vmalloc() area is valid and can use memcpy().
+ *      This is for routines which have to access vmalloc area without
+ *      any informaion, as /dev/kmem.
+ *
+ *      The caller should guarantee KM_USER1 is not used.
+ */
+
 long vwrite(char *buf, char *addr, unsigned long count)
 {
         struct vm_struct *tmp;
-        char *vaddr, *buf_start = buf;
-        unsigned long n;
+        char *vaddr;
+        unsigned long n, buflen;
+        int copied = 0;
 
         /* Don't allow overflow */
         if ((unsigned long) addr + count < count)
                 count = -(unsigned long) addr;
+        buflen = count;
 
         read_lock(&vmlist_lock);
-        for (tmp = vmlist; tmp; tmp = tmp->next) {
+        for (tmp = vmlist; count && tmp; tmp = tmp->next) {
                 vaddr = (char *) tmp->addr;
                 if (addr >= vaddr + tmp->size - PAGE_SIZE)
                         continue;
@@ -1686,18 +1858,21 @@ long vwrite(char *buf, char *addr, unsigned long count)
                         count--;
                 }
                 n = vaddr + tmp->size - PAGE_SIZE - addr;
-                do {
-                        if (count == 0)
-                                goto finished;
-                        *addr = *buf;
-                        buf++;
-                        addr++;
-                        count--;
-                } while (--n > 0);
+                if (n > count)
+                        n = count;
+                if (!(tmp->flags & VM_IOREMAP)) {
+                        aligned_vwrite(buf, addr, n);
+                        copied++;
+                }
+                buf += n;
+                addr += n;
+                count -= n;
         }
 finished:
         read_unlock(&vmlist_lock);
-        return buf - buf_start;
+        if (!copied)
+                return 0;
+        return buflen;
 }
 
 /**
@@ -1818,6 +1993,286 @@ void free_vm_area(struct vm_struct *area)
 }
 EXPORT_SYMBOL_GPL(free_vm_area);
 
+static struct vmap_area *node_to_va(struct rb_node *n)
+{
+        return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
+}
+
+/**
+ * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
+ * @end: target address
+ * @pnext: out arg for the next vmap_area
+ * @pprev: out arg for the previous vmap_area
+ *
+ * Returns: %true if either or both of next and prev are found,
+ *          %false if no vmap_area exists
+ *
+ * Find vmap_areas end addresses of which enclose @end.  ie. if not
+ * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
+ */
+static bool pvm_find_next_prev(unsigned long end,
+                               struct vmap_area **pnext,
+                               struct vmap_area **pprev)
+{
+        struct rb_node *n = vmap_area_root.rb_node;
+        struct vmap_area *va = NULL;
+
+        while (n) {
+                va = rb_entry(n, struct vmap_area, rb_node);
+                if (end < va->va_end)
+                        n = n->rb_left;
+                else if (end > va->va_end)
+                        n = n->rb_right;
+                else
+                        break;
+        }
+
+        if (!va)
+                return false;
+
+        if (va->va_end > end) {
+                *pnext = va;
+                *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+        } else {
+                *pprev = va;
+                *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
+        }
+        return true;
+}
+
+/**
+ * pvm_determine_end - find the highest aligned address between two vmap_areas
+ * @pnext: in/out arg for the next vmap_area
+ * @pprev: in/out arg for the previous vmap_area
+ * @align: alignment
+ *
+ * Returns: determined end address
+ *
+ * Find the highest aligned address between *@pnext and *@pprev below
+ * VMALLOC_END.  *@pnext and *@pprev are adjusted so that the aligned
+ * down address is between the end addresses of the two vmap_areas.
+ *
+ * Please note that the address returned by this function may fall
+ * inside *@pnext vmap_area.  The caller is responsible for checking
+ * that.
+ */
+static unsigned long pvm_determine_end(struct vmap_area **pnext,
+                                       struct vmap_area **pprev,
+                                       unsigned long align)
+{
+        const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+        unsigned long addr;
+
+        if (*pnext)
+                addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
+        else
+                addr = vmalloc_end;
+
+        while (*pprev && (*pprev)->va_end > addr) {
+                *pnext = *pprev;
+                *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+        }
+
+        return addr;
+}
+
+/**
+ * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
+ * @offsets: array containing offset of each area
+ * @sizes: array containing size of each area
+ * @nr_vms: the number of areas to allocate
+ * @align: alignment, all entries in @offsets and @sizes must be aligned to this
+ * @gfp_mask: allocation mask
+ *
+ * Returns: kmalloc'd vm_struct pointer array pointing to allocated
+ *          vm_structs on success, %NULL on failure
+ *
+ * Percpu allocator wants to use congruent vm areas so that it can
+ * maintain the offsets among percpu areas.  This function allocates
+ * congruent vmalloc areas for it.  These areas tend to be scattered
+ * pretty far, distance between two areas easily going up to
+ * gigabytes.  To avoid interacting with regular vmallocs, these areas
+ * are allocated from top.
+ *
+ * Despite its complicated look, this allocator is rather simple.  It
+ * does everything top-down and scans areas from the end looking for
+ * matching slot.  While scanning, if any of the areas overlaps with
+ * existing vmap_area, the base address is pulled down to fit the
+ * area.  Scanning is repeated till all the areas fit and then all
+ * necessary data structres are inserted and the result is returned.
+ */
+struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
+                                     const size_t *sizes, int nr_vms,
+                                     size_t align, gfp_t gfp_mask)
+{
+        const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
+        const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+        struct vmap_area **vas, *prev, *next;
+        struct vm_struct **vms;
+        int area, area2, last_area, term_area;
+        unsigned long base, start, end, last_end;
+        bool purged = false;
+
+        gfp_mask &= GFP_RECLAIM_MASK;
+
+        /* verify parameters and allocate data structures */
+        BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
+        for (last_area = 0, area = 0; area < nr_vms; area++) {
+                start = offsets[area];
+                end = start + sizes[area];
+
+                /* is everything aligned properly? */
+                BUG_ON(!IS_ALIGNED(offsets[area], align));
+                BUG_ON(!IS_ALIGNED(sizes[area], align));
+
+                /* detect the area with the highest address */
+                if (start > offsets[last_area])
+                        last_area = area;
+
+                for (area2 = 0; area2 < nr_vms; area2++) {
+                        unsigned long start2 = offsets[area2];
+                        unsigned long end2 = start2 + sizes[area2];
+
+                        if (area2 == area)
+                                continue;
+
+                        BUG_ON(start2 >= start && start2 < end);
+                        BUG_ON(end2 <= end && end2 > start);
+                }
+        }
+        last_end = offsets[last_area] + sizes[last_area];
+
+        if (vmalloc_end - vmalloc_start < last_end) {
+                WARN_ON(true);
+                return NULL;
+        }
+
+        vms = kzalloc(sizeof(vms[0]) * nr_vms, gfp_mask);
+        vas = kzalloc(sizeof(vas[0]) * nr_vms, gfp_mask);
+        if (!vas || !vms)
+                goto err_free;
+
+        for (area = 0; area < nr_vms; area++) {
+                vas[area] = kzalloc(sizeof(struct vmap_area), gfp_mask);
+                vms[area] = kzalloc(sizeof(struct vm_struct), gfp_mask);
+                if (!vas[area] || !vms[area])
+                        goto err_free;
+        }
+retry:
+        spin_lock(&vmap_area_lock);
+
+        /* start scanning - we scan from the top, begin with the last area */
+        area = term_area = last_area;
+        start = offsets[area];
+        end = start + sizes[area];
+
+        if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
+                base = vmalloc_end - last_end;
+                goto found;
+        }
+        base = pvm_determine_end(&next, &prev, align) - end;
+
+        while (true) {
+                BUG_ON(next && next->va_end <= base + end);
+                BUG_ON(prev && prev->va_end > base + end);
+
+                /*
+                 * base might have underflowed, add last_end before
+                 * comparing.
+                 */
+                if (base + last_end < vmalloc_start + last_end) {
+                        spin_unlock(&vmap_area_lock);
+                        if (!purged) {
+                                purge_vmap_area_lazy();
+                                purged = true;
+                                goto retry;
+                        }
+                        goto err_free;
+                }
+
+                /*
+                 * If next overlaps, move base downwards so that it's
+                 * right below next and then recheck.
+                 */
+                if (next && next->va_start < base + end) {
+                        base = pvm_determine_end(&next, &prev, align) - end;
+                        term_area = area;
+                        continue;
+                }
+
+                /*
+                 * If prev overlaps, shift down next and prev and move
+                 * base so that it's right below new next and then
+                 * recheck.
+                 */
+                if (prev && prev->va_end > base + start)  {
+                        next = prev;
+                        prev = node_to_va(rb_prev(&next->rb_node));
+                        base = pvm_determine_end(&next, &prev, align) - end;
+                        term_area = area;
+                        continue;
+                }
+
+                /*
+                 * This area fits, move on to the previous one.  If
+                 * the previous one is the terminal one, we're done.
+                 */
+                area = (area + nr_vms - 1) % nr_vms;
+                if (area == term_area)
+                        break;
+                start = offsets[area];
+                end = start + sizes[area];
+                pvm_find_next_prev(base + end, &next, &prev);
+        }
+found:
+        /* we've found a fitting base, insert all va's */
+        for (area = 0; area < nr_vms; area++) {
+                struct vmap_area *va = vas[area];
+
+                va->va_start = base + offsets[area];
+                va->va_end = va->va_start + sizes[area];
+                __insert_vmap_area(va);
+        }
+
+        vmap_area_pcpu_hole = base + offsets[last_area];
+
+        spin_unlock(&vmap_area_lock);
+
+        /* insert all vm's */
+        for (area = 0; area < nr_vms; area++)
+                insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+                                  pcpu_get_vm_areas);
+
+        kfree(vas);
+        return vms;
+
+err_free:
+        for (area = 0; area < nr_vms; area++) {
+                if (vas)
+                        kfree(vas[area]);
+                if (vms)
+                        kfree(vms[area]);
+        }
+        kfree(vas);
+        kfree(vms);
+        return NULL;
+}
+
+/**
+ * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
+ * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
+ * @nr_vms: the number of allocated areas
+ *
+ * Free vm_structs and the array allocated by pcpu_get_vm_areas().
+ */
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
+{
+        int i;
+
+        for (i = 0; i < nr_vms; i++)
+                free_vm_area(vms[i]);
+        kfree(vms);
+}
 
 #ifdef CONFIG_PROC_FS
 static void *s_start(struct seq_file *m, loff_t *pos)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 94e86dd6954c..64e438898832 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -148,8 +148,8 @@ static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
         return &zone->reclaim_stat;
 }
 
-static unsigned long zone_nr_pages(struct zone *zone, struct scan_control *sc,
-                                   enum lru_list lru)
+static unsigned long zone_nr_lru_pages(struct zone *zone,
+                                struct scan_control *sc, enum lru_list lru)
 {
         if (!scanning_global_lru(sc))
                 return mem_cgroup_zone_nr_pages(sc->mem_cgroup, zone, lru);
@@ -286,7 +286,12 @@ static inline int page_mapping_inuse(struct page *page)
 
 static inline int is_page_cache_freeable(struct page *page)
 {
-        return page_count(page) - !!page_has_private(page) == 2;
+        /*
+         * A freeable page cache page is referenced only by the caller
+         * that isolated the page, the page cache radix tree and
+         * optional buffer heads at page->private.
+         */
+        return page_count(page) - page_has_private(page) == 2;
 }
 
 static int may_write_to_queue(struct backing_dev_info *bdi)
@@ -361,7 +366,6 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
          * block, for some throttling. This happens by accident, because
          * swap_backing_dev_info is bust: it doesn't reflect the
          * congestion state of the swapdevs.  Easy to fix, if needed.
-         * See swapfile.c:page_queue_congested().
          */
         if (!is_page_cache_freeable(page))
                 return PAGE_KEEP;
@@ -531,7 +535,7 @@ redo:
                  * unevictable page on [in]active list.
                  * We know how to handle that.
                  */
-                lru = active + page_is_file_cache(page);
+                lru = active + page_lru_base_type(page);
                 lru_cache_add_lru(page, lru);
         } else {
                 /*
@@ -659,7 +663,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                  * processes. Try to unmap it here.
                  */
                 if (page_mapped(page) && mapping) {
-                        switch (try_to_unmap(page, 0)) {
+                        switch (try_to_unmap(page, TTU_UNMAP)) {
                         case SWAP_FAIL:
                                 goto activate_locked;
                         case SWAP_AGAIN:
@@ -821,7 +825,7 @@ int __isolate_lru_page(struct page *page, int mode, int file)
         if (mode != ISOLATE_BOTH && (!PageActive(page) != !mode))
                 return ret;
 
-        if (mode != ISOLATE_BOTH && (!page_is_file_cache(page) != !file))
+        if (mode != ISOLATE_BOTH && page_is_file_cache(page) != file)
                 return ret;
 
         /*
@@ -935,6 +939,16 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                         /* Check that we have not crossed a zone boundary. */
                         if (unlikely(page_zone_id(cursor_page) != zone_id))
                                 continue;
+
+                        /*
+                         * If we don't have enough swap space, reclaiming of
+                         * anon page which don't already have a swap slot is
+                         * pointless.
+                         */
+                        if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&
+                                        !PageSwapCache(cursor_page))
+                                continue;
+
                         if (__isolate_lru_page(cursor_page, mode, file) == 0) {
                                 list_move(&cursor_page->lru, dst);
                                 mem_cgroup_del_lru(cursor_page);
@@ -961,7 +975,7 @@ static unsigned long isolate_pages_global(unsigned long nr,
         if (file)
                 lru += LRU_FILE;
         return isolate_lru_pages(nr, &z->lru[lru].list, dst, scanned, order,
-                                                                mode, !!file);
+                                                                mode, file);
 }
 
 /*
@@ -976,7 +990,7 @@ static unsigned long clear_active_flags(struct list_head *page_list,
         struct page *page;
 
         list_for_each_entry(page, page_list, lru) {
-                lru = page_is_file_cache(page);
+                lru = page_lru_base_type(page);
                 if (PageActive(page)) {
                         lru += LRU_ACTIVE;
                         ClearPageActive(page);
@@ -1034,6 +1048,31 @@ int isolate_lru_page(struct page *page)
 }
 
 /*
+ * Are there way too many processes in the direct reclaim path already?
+ */
+static int too_many_isolated(struct zone *zone, int file,
+                struct scan_control *sc)
+{
+        unsigned long inactive, isolated;
+
+        if (current_is_kswapd())
+                return 0;
+
+        if (!scanning_global_lru(sc))
+                return 0;
+
+        if (file) {
+                inactive = zone_page_state(zone, NR_INACTIVE_FILE);
+                isolated = zone_page_state(zone, NR_ISOLATED_FILE);
+        } else {
+                inactive = zone_page_state(zone, NR_INACTIVE_ANON);
+                isolated = zone_page_state(zone, NR_ISOLATED_ANON);
+        }
+
+        return isolated > inactive;
+}
+
+/*
  * shrink_inactive_list() is a helper for shrink_zone().  It returns the number
  * of reclaimed pages
  */
@@ -1048,6 +1087,14 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
         struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
         int lumpy_reclaim = 0;
 
+        while (unlikely(too_many_isolated(zone, file, sc))) {
+                congestion_wait(WRITE, HZ/10);
+
+                /* We are about to die and free our memory. Return now. */
+                if (fatal_signal_pending(current))
+                        return SWAP_CLUSTER_MAX;
+        }
+
         /*
          * If we need a large contiguous chunk of memory, or have
          * trouble getting a small set of contiguous pages, we
@@ -1072,10 +1119,26 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                 unsigned long nr_active;
                 unsigned int count[NR_LRU_LISTS] = { 0, };
                 int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE;
+                unsigned long nr_anon;
+                unsigned long nr_file;
 
                 nr_taken = sc->isolate_pages(sc->swap_cluster_max,
                              &page_list, &nr_scan, sc->order, mode,
                                 zone, sc->mem_cgroup, 0, file);
+
+                if (scanning_global_lru(sc)) {
+                        zone->pages_scanned += nr_scan;
+                        if (current_is_kswapd())
+                                __count_zone_vm_events(PGSCAN_KSWAPD, zone,
+                                                       nr_scan);
+                        else
+                                __count_zone_vm_events(PGSCAN_DIRECT, zone,
+                                                       nr_scan);
+                }
+
+                if (nr_taken == 0)
+                        goto done;
+
                 nr_active = clear_active_flags(&page_list, count);
                 __count_vm_events(PGDEACTIVATE, nr_active);
 
@@ -1088,8 +1151,10 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                 __mod_zone_page_state(zone, NR_INACTIVE_ANON,
                                                 -count[LRU_INACTIVE_ANON]);
 
-                if (scanning_global_lru(sc))
-                        zone->pages_scanned += nr_scan;
+                nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON];
+                nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE];
+                __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon);
+                __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file);
 
                 reclaim_stat->recent_scanned[0] += count[LRU_INACTIVE_ANON];
                 reclaim_stat->recent_scanned[0] += count[LRU_ACTIVE_ANON];
@@ -1123,18 +1188,12 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                 }
 
                 nr_reclaimed += nr_freed;
+
                 local_irq_disable();
-                if (current_is_kswapd()) {
-                        __count_zone_vm_events(PGSCAN_KSWAPD, zone, nr_scan);
+                if (current_is_kswapd())
                         __count_vm_events(KSWAPD_STEAL, nr_freed);
-                } else if (scanning_global_lru(sc))
-                        __count_zone_vm_events(PGSCAN_DIRECT, zone, nr_scan);
-
                 __count_zone_vm_events(PGSTEAL, zone, nr_freed);
 
-                if (nr_taken == 0)
-                        goto done;
-
                 spin_lock(&zone->lru_lock);
                 /*
                  * Put back any unfreeable pages.
@@ -1153,8 +1212,8 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                         SetPageLRU(page);
                         lru = page_lru(page);
                         add_page_to_lru_list(zone, page, lru);
-                        if (PageActive(page)) {
-                                int file = !!page_is_file_cache(page);
+                        if (is_active_lru(lru)) {
+                                int file = is_file_lru(lru);
                                 reclaim_stat->recent_rotated[file]++;
                         }
                         if (!pagevec_add(&pvec, page)) {
@@ -1163,10 +1222,13 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                                 spin_lock_irq(&zone->lru_lock);
                         }
                 }
+                __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon);
+                __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file);
+
         } while (nr_scanned < max_scan);
-        spin_unlock(&zone->lru_lock);
+
 done:
-        local_irq_enable();
+        spin_unlock_irq(&zone->lru_lock);
         pagevec_release(&pvec);
         return nr_reclaimed;
 }
@@ -1215,15 +1277,10 @@ static void move_active_pages_to_lru(struct zone *zone,
 
         while (!list_empty(list)) {
                 page = lru_to_page(list);
-                prefetchw_prev_lru_page(page, list, flags);
 
                 VM_BUG_ON(PageLRU(page));
                 SetPageLRU(page);
 
-                VM_BUG_ON(!PageActive(page));
-                if (!is_active_lru(lru))
-                        ClearPageActive(page);  /* we are de-activating */
-
                 list_move(&page->lru, &zone->lru[lru].list);
                 mem_cgroup_add_lru_list(page, lru);
                 pgmoved++;
@@ -1244,7 +1301,7 @@ static void move_active_pages_to_lru(struct zone *zone,
 static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                         struct scan_control *sc, int priority, int file)
 {
-        unsigned long pgmoved;
+        unsigned long nr_taken;
         unsigned long pgscanned;
         unsigned long vm_flags;
         LIST_HEAD(l_hold);      /* The pages which were snipped off */
@@ -1252,10 +1309,11 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
         LIST_HEAD(l_inactive);
         struct page *page;
         struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+        unsigned long nr_rotated = 0;
 
         lru_add_drain();
         spin_lock_irq(&zone->lru_lock);
-        pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
+        nr_taken = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
                                         ISOLATE_ACTIVE, zone,
                                         sc->mem_cgroup, 1, file);
         /*
@@ -1265,16 +1323,16 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
         if (scanning_global_lru(sc)) {
                 zone->pages_scanned += pgscanned;
         }
-        reclaim_stat->recent_scanned[!!file] += pgmoved;
+        reclaim_stat->recent_scanned[file] += nr_taken;
 
         __count_zone_vm_events(PGREFILL, zone, pgscanned);
         if (file)
-                __mod_zone_page_state(zone, NR_ACTIVE_FILE, -pgmoved);
+                __mod_zone_page_state(zone, NR_ACTIVE_FILE, -nr_taken);
         else
-                __mod_zone_page_state(zone, NR_ACTIVE_ANON, -pgmoved);
+                __mod_zone_page_state(zone, NR_ACTIVE_ANON, -nr_taken);
+        __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, nr_taken);
         spin_unlock_irq(&zone->lru_lock);
 
-        pgmoved = 0;  /* count referenced (mapping) mapped pages */
         while (!list_empty(&l_hold)) {
                 cond_resched();
                 page = lru_to_page(&l_hold);
@@ -1288,7 +1346,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                 /* page_referenced clears PageReferenced */
                 if (page_mapping_inuse(page) &&
                     page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
-                        pgmoved++;
+                        nr_rotated++;
                         /*
                          * Identify referenced, file-backed active pages and
                          * give them one more trip around the active list. So
@@ -1304,6 +1362,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                         }
                 }
 
+                ClearPageActive(page);  /* we are de-activating */
                 list_add(&page->lru, &l_inactive);
         }
 
@@ -1317,13 +1376,13 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
          * helps balance scan pressure between file and anonymous pages in
          * get_scan_ratio.
          */
-        reclaim_stat->recent_rotated[!!file] += pgmoved;
+        reclaim_stat->recent_rotated[file] += nr_rotated;
 
         move_active_pages_to_lru(zone, &l_active,
                                                 LRU_ACTIVE + file * LRU_FILE);
         move_active_pages_to_lru(zone, &l_inactive,
                                                 LRU_BASE   + file * LRU_FILE);
-
+        __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken);
         spin_unlock_irq(&zone->lru_lock);
 }
 
@@ -1429,10 +1488,10 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
         unsigned long ap, fp;
         struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
 
-        anon  = zone_nr_pages(zone, sc, LRU_ACTIVE_ANON) +
-                zone_nr_pages(zone, sc, LRU_INACTIVE_ANON);
-        file  = zone_nr_pages(zone, sc, LRU_ACTIVE_FILE) +
-                zone_nr_pages(zone, sc, LRU_INACTIVE_FILE);
+        anon  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
+                zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
+        file  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
+                zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
 
         if (scanning_global_lru(sc)) {
                 free  = zone_page_state(zone, NR_FREE_PAGES);
@@ -1526,6 +1585,7 @@ static void shrink_zone(int priority, struct zone *zone,
         enum lru_list l;
         unsigned long nr_reclaimed = sc->nr_reclaimed;
         unsigned long swap_cluster_max = sc->swap_cluster_max;
+        struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
         int noswap = 0;
 
         /* If we have no swap space, do not bother scanning anon pages. */
@@ -1540,17 +1600,14 @@ static void shrink_zone(int priority, struct zone *zone,
                 int file = is_file_lru(l);
                 unsigned long scan;
 
-                scan = zone_nr_pages(zone, sc, l);
+                scan = zone_nr_lru_pages(zone, sc, l);
                 if (priority || noswap) {
                         scan >>= priority;
                         scan = (scan * percent[file]) / 100;
                 }
-                if (scanning_global_lru(sc))
-                        nr[l] = nr_scan_try_batch(scan,
-                                                  &zone->lru[l].nr_saved_scan,
-                                                  swap_cluster_max);
-                else
-                        nr[l] = scan;
+                nr[l] = nr_scan_try_batch(scan,
+                                          &reclaim_stat->nr_saved_scan[l],
+                                          swap_cluster_max);
         }
 
         while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
@@ -1652,10 +1709,10 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
  *
  * If the caller is !__GFP_FS then the probability of a failure is reasonably
  * high - the zone may be full of dirty or under-writeback pages, which this
- * caller can't do much about.  We kick pdflush and take explicit naps in the
- * hope that some of these pages can be written.  But if the allocating task
- * holds filesystem locks which prevent writeout this might not work, and the
- * allocation attempt will fail.
+ * caller can't do much about.  We kick the writeback threads and take explicit
+ * naps in the hope that some of these pages can be written.  But if the
+ * allocating task holds filesystem locks which prevent writeout this might not
+ * work, and the allocation attempt will fail.
  *
  * returns:     0, if no pages reclaimed
  *              else, the number of pages reclaimed
@@ -1685,7 +1742,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                         if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
                                 continue;
 
-                        lru_pages += zone_lru_pages(zone);
+                        lru_pages += zone_reclaimable_pages(zone);
                 }
         }
 
@@ -1720,7 +1777,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                  */
                 if (total_scanned > sc->swap_cluster_max +
                                         sc->swap_cluster_max / 2) {
-                        wakeup_pdflush(laptop_mode ? 0 : total_scanned);
+                        wakeup_flusher_threads(laptop_mode ? 0 : total_scanned);
                         sc->may_writepage = 1;
                 }
 
@@ -1779,11 +1836,45 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 
+unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
+                                                gfp_t gfp_mask, bool noswap,
+                                                unsigned int swappiness,
+                                                struct zone *zone, int nid)
+{
+        struct scan_control sc = {
+                .may_writepage = !laptop_mode,
+                .may_unmap = 1,
+                .may_swap = !noswap,
+                .swap_cluster_max = SWAP_CLUSTER_MAX,
+                .swappiness = swappiness,
+                .order = 0,
+                .mem_cgroup = mem,
+                .isolate_pages = mem_cgroup_isolate_pages,
+        };
+        nodemask_t nm  = nodemask_of_node(nid);
+
+        sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
+                        (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
+        sc.nodemask = &nm;
+        sc.nr_reclaimed = 0;
+        sc.nr_scanned = 0;
+        /*
+         * NOTE: Although we can get the priority field, using it
+         * here is not a good idea, since it limits the pages we can scan.
+         * if we don't reclaim here, the shrink_zone from balance_pgdat
+         * will pick up pages from other mem cgroup's as well. We hack
+         * the priority and make it zero.
+         */
+        shrink_zone(0, zone, &sc);
+        return sc.nr_reclaimed;
+}
+
 unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
                                            gfp_t gfp_mask,
                                            bool noswap,
                                            unsigned int swappiness)
 {
+        struct zonelist *zonelist;
         struct scan_control sc = {
                 .may_writepage = !laptop_mode,
                 .may_unmap = 1,
@@ -1795,7 +1886,6 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
                 .isolate_pages = mem_cgroup_isolate_pages,
                 .nodemask = NULL, /* we don't care the placement */
         };
-        struct zonelist *zonelist;
 
         sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
                         (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
@@ -1902,7 +1992,7 @@ loop_again:
                 for (i = 0; i <= end_zone; i++) {
                         struct zone *zone = pgdat->node_zones + i;
 
-                        lru_pages += zone_lru_pages(zone);
+                        lru_pages += zone_reclaimable_pages(zone);
                 }
 
                 /*
@@ -1917,6 +2007,7 @@ loop_again:
                 for (i = 0; i <= end_zone; i++) {
                         struct zone *zone = pgdat->node_zones + i;
                         int nr_slab;
+                        int nid, zid;
 
                         if (!populated_zone(zone))
                                 continue;
@@ -1931,6 +2022,15 @@ loop_again:
                         temp_priority[i] = priority;
                         sc.nr_scanned = 0;
                         note_zone_scanning_priority(zone, priority);
+
+                        nid = pgdat->node_id;
+                        zid = zone_idx(zone);
+                        /*
+                         * Call soft limit reclaim before calling shrink_zone.
+                         * For now we ignore the return value
+                         */
+                        mem_cgroup_soft_limit_reclaim(zone, order, sc.gfp_mask,
+                                                        nid, zid);
                         /*
                          * We put equal pressure on every zone, unless one
                          * zone has way too many pages free already.
@@ -1946,7 +2046,7 @@ loop_again:
                         if (zone_is_all_unreclaimable(zone))
                                 continue;
                         if (nr_slab == 0 && zone->pages_scanned >=
-                                                (zone_lru_pages(zone) * 6))
+                                        (zone_reclaimable_pages(zone) * 6))
                                         zone_set_flag(zone,
                                                       ZONE_ALL_UNRECLAIMABLE);
                         /*
@@ -2113,12 +2213,39 @@ void wakeup_kswapd(struct zone *zone, int order)
         wake_up_interruptible(&pgdat->kswapd_wait);
 }
 
-unsigned long global_lru_pages(void)
+/*
+ * The reclaimable count would be mostly accurate.
+ * The less reclaimable pages may be
+ * - mlocked pages, which will be moved to unevictable list when encountered
+ * - mapped pages, which may require several travels to be reclaimed
+ * - dirty pages, which is not "instantly" reclaimable
+ */
+unsigned long global_reclaimable_pages(void)
+{
+        int nr;
+
+        nr = global_page_state(NR_ACTIVE_FILE) +
+             global_page_state(NR_INACTIVE_FILE);
+
+        if (nr_swap_pages > 0)
+                nr += global_page_state(NR_ACTIVE_ANON) +
+                      global_page_state(NR_INACTIVE_ANON);
+
+        return nr;
+}
+
+unsigned long zone_reclaimable_pages(struct zone *zone)
 {
-        return global_page_state(NR_ACTIVE_ANON)
-                + global_page_state(NR_ACTIVE_FILE)
-                + global_page_state(NR_INACTIVE_ANON)
-                + global_page_state(NR_INACTIVE_FILE);
+        int nr;
+
+        nr = zone_page_state(zone, NR_ACTIVE_FILE) +
+             zone_page_state(zone, NR_INACTIVE_FILE);
+
+        if (nr_swap_pages > 0)
+                nr += zone_page_state(zone, NR_ACTIVE_ANON) +
+                      zone_page_state(zone, NR_INACTIVE_ANON);
+
+        return nr;
 }
 
 #ifdef CONFIG_HIBERNATION
@@ -2133,6 +2260,7 @@ static void shrink_all_zones(unsigned long nr_pages, int prio,
 {
         struct zone *zone;
         unsigned long nr_reclaimed = 0;
+        struct zone_reclaim_stat *reclaim_stat;
 
         for_each_populated_zone(zone) {
                 enum lru_list l;
@@ -2149,11 +2277,14 @@ static void shrink_all_zones(unsigned long nr_pages, int prio,
                                                 l == LRU_ACTIVE_FILE))
                                 continue;
 
-                        zone->lru[l].nr_saved_scan += (lru_pages >> prio) + 1;
-                        if (zone->lru[l].nr_saved_scan >= nr_pages || pass > 3) {
+                        reclaim_stat = get_reclaim_stat(zone, sc);
+                        reclaim_stat->nr_saved_scan[l] +=
+                                                (lru_pages >> prio) + 1;
+                        if (reclaim_stat->nr_saved_scan[l]
+                                                >= nr_pages || pass > 3) {
                                 unsigned long nr_to_scan;
 
-                                zone->lru[l].nr_saved_scan = 0;
+                                reclaim_stat->nr_saved_scan[l] = 0;
                                 nr_to_scan = min(nr_pages, lru_pages);
                                 nr_reclaimed += shrink_list(l, nr_to_scan, zone,
                                                                 sc, prio);
@@ -2190,7 +2321,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
 
         current->reclaim_state = &reclaim_state;
 
-        lru_pages = global_lru_pages();
+        lru_pages = global_reclaimable_pages();
         nr_slab = global_page_state(NR_SLAB_RECLAIMABLE);
         /* If slab caches are huge, it's better to hit them first */
         while (nr_slab >= lru_pages) {
@@ -2232,7 +2363,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
 
                         reclaim_state.reclaimed_slab = 0;
                         shrink_slab(sc.nr_scanned, sc.gfp_mask,
-                                        global_lru_pages());
+                                    global_reclaimable_pages());
                         sc.nr_reclaimed += reclaim_state.reclaimed_slab;
                         if (sc.nr_reclaimed >= nr_pages)
                                 goto out;
@@ -2249,7 +2380,8 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
         if (!sc.nr_reclaimed) {
                 do {
                         reclaim_state.reclaimed_slab = 0;
-                        shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
+                        shrink_slab(nr_pages, sc.gfp_mask,
+                                    global_reclaimable_pages());
                         sc.nr_reclaimed += reclaim_state.reclaimed_slab;
                 } while (sc.nr_reclaimed < nr_pages &&
                                 reclaim_state.reclaimed_slab > 0);
@@ -2569,7 +2701,7 @@ static void check_move_unevictable_page(struct page *page, struct zone *zone)
 retry:
         ClearPageUnevictable(page);
         if (page_evictable(page, NULL)) {
-                enum lru_list l = LRU_INACTIVE_ANON + page_is_file_cache(page);
+                enum lru_list l = page_lru_base_type(page);
 
                 __dec_zone_state(zone, NR_UNEVICTABLE);
                 list_move(&page->lru, &zone->lru[l].list);
@@ -2712,10 +2844,10 @@ static void scan_all_zones_unevictable_pages(void)
 unsigned long scan_unevictable_pages;
 
 int scan_unevictable_handler(struct ctl_table *table, int write,
-                           struct file *file, void __user *buffer,
+                           void __user *buffer,
                            size_t *length, loff_t *ppos)
 {
-        proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+        proc_doulongvec_minmax(table, write, buffer, length, ppos);
 
         if (write && *(unsigned long *)table->data)
                 scan_all_zones_unevictable_pages();
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 138bed53706e..c81321f9feec 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -639,11 +639,14 @@ static const char * const vmstat_text[] = {
         "nr_slab_reclaimable",
         "nr_slab_unreclaimable",
         "nr_page_table_pages",
+        "nr_kernel_stack",
         "nr_unstable",
         "nr_bounce",
         "nr_vmscan_write",
         "nr_writeback_temp",
-
+        "nr_isolated_anon",
+        "nr_isolated_file",
+        "nr_shmem",
 #ifdef CONFIG_NUMA
         "numa_hit",
         "numa_miss",