16 files changed, 258 insertions, 110 deletions

diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index ead764b2728f..de1e6c4dccff 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -137,6 +137,17 @@ errors=panic|continue|remount-ro
                  without doing anything or remount the partition in
                  read-only mode (default behavior).
 
+discard       -- If set, issues discard/TRIM commands to the block
+                 device when blocks are freed. This is useful for SSD devices
+                 and sparse/thinly-provisoned LUNs.
+
+nfs           -- This option maintains an index (cache) of directory
+                 inodes by i_logstart which is used by the nfs-related code to
+                 improve look-ups.
+
+                 Enable this only if you want to export the FAT filesystem
+                 over NFS
+
 <bool>: 0,1,yes,no,true,false
 
 TODO
diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt
index f8551b3879f8..4ac359b7aa17 100644
--- a/Documentation/vm/hugetlbpage.txt
+++ b/Documentation/vm/hugetlbpage.txt
@@ -299,11 +299,17 @@ map_hugetlb.c.
 *******************************************************************
 
 /*
- * hugepage-shm:  see Documentation/vm/hugepage-shm.c
+ * map_hugetlb: see tools/testing/selftests/vm/map_hugetlb.c
  */
 
 *******************************************************************
 
 /*
- * hugepage-mmap:  see Documentation/vm/hugepage-mmap.c
+ * hugepage-shm:  see tools/testing/selftests/vm/hugepage-shm.c
+ */
+
+*******************************************************************
+
+/*
+ * hugepage-mmap:  see tools/testing/selftests/vm/hugepage-mmap.c
  */
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index f6679a7fb8ca..b91e48512425 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -56,9 +56,16 @@ static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
 }
 
 /*
- * search for a shareable pmd page for hugetlb.
+ * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
+ * and returns the corresponding pte. While this is not necessary for the
+ * !shared pmd case because we can allocate the pmd later as well, it makes the
+ * code much cleaner. pmd allocation is essential for the shared case because
+ * pud has to be populated inside the same i_mmap_mutex section - otherwise
+ * racing tasks could either miss the sharing (see huge_pte_offset) or select a
+ * bad pmd for sharing.
  */
-static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
+static pte_t *
+huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
 {
         struct vm_area_struct *vma = find_vma(mm, addr);
         struct address_space *mapping = vma->vm_file->f_mapping;
@@ -68,9 +75,10 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
         struct vm_area_struct *svma;
         unsigned long saddr;
         pte_t *spte = NULL;
+        pte_t *pte;
 
         if (!vma_shareable(vma, addr))
-                return;
+                return (pte_t *)pmd_alloc(mm, pud, addr);
 
         mutex_lock(&mapping->i_mmap_mutex);
         vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {
@@ -97,7 +105,9 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
                 put_page(virt_to_page(spte));
         spin_unlock(&mm->page_table_lock);
 out:
+        pte = (pte_t *)pmd_alloc(mm, pud, addr);
         mutex_unlock(&mapping->i_mmap_mutex);
+        return pte;
 }
 
 /*
@@ -142,8 +152,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
                 } else {
                         BUG_ON(sz != PMD_SIZE);
                         if (pud_none(*pud))
-                                huge_pmd_share(mm, addr, pud);
-                        pte = (pte_t *) pmd_alloc(mm, pud, addr);
+                                pte = huge_pmd_share(mm, addr, pud);
+                        else
+                                pte = (pte_t *)pmd_alloc(mm, pud, addr);
                 }
         }
         BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
index acda773b3720..38aa6dda6b81 100644
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -763,16 +763,7 @@ static void complete_scsi_command(CommandList_struct *c, int timeout,
                 {
                         case CMD_TARGET_STATUS:
                                 /* Pass it up to the upper layers... */
-                                if( ei->ScsiStatus)
-                                {
-#if 0
-                                        printk(KERN_WARNING "cciss: cmd %p "
-                                                "has SCSI Status = %x\n",
-                                                c, ei->ScsiStatus);
-#endif
-                                        cmd->result |= (ei->ScsiStatus << 1);
-                                }
-                                else {  /* scsi status is zero??? How??? */
+                                if (!ei->ScsiStatus) {
                                         
         /* Ordinarily, this case should never happen, but there is a bug
            in some released firmware revisions that allows it to happen
diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c
index 540795cd0760..d9279385304d 100644
--- a/drivers/clocksource/cs5535-clockevt.c
+++ b/drivers/clocksource/cs5535-clockevt.c
@@ -53,7 +53,7 @@ static struct cs5535_mfgpt_timer *cs5535_event_clock;
 #define MFGPT_PERIODIC (MFGPT_HZ / HZ)
 
 /*
- * The MFPGT timers on the CS5536 provide us with suitable timers to use
+ * The MFGPT timers on the CS5536 provide us with suitable timers to use
  * as clock event sources - not as good as a HPET or APIC, but certainly
  * better than the PIT.  This isn't a general purpose MFGPT driver, but
  * a simplified one designed specifically to act as a clock event source.
@@ -144,7 +144,7 @@ static int __init cs5535_mfgpt_init(void)
 
         timer = cs5535_mfgpt_alloc_timer(MFGPT_TIMER_ANY, MFGPT_DOMAIN_WORKING);
         if (!timer) {
-                printk(KERN_ERR DRV_NAME ": Could not allocate MFPGT timer\n");
+                printk(KERN_ERR DRV_NAME ": Could not allocate MFGPT timer\n");
                 return -ENODEV;
         }
         cs5535_event_clock = timer;
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
index 87b251ab6ec5..b9e2000969f0 100644
--- a/drivers/misc/sgi-xp/xpc_uv.c
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -18,6 +18,8 @@
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <asm/uv/uv_hub.h>
@@ -59,6 +61,8 @@ static struct xpc_heartbeat_uv *xpc_heartbeat_uv;
                                          XPC_NOTIFY_MSG_SIZE_UV)
 #define XPC_NOTIFY_IRQ_NAME             "xpc_notify"
 
+static int xpc_mq_node = -1;
+
 static struct xpc_gru_mq_uv *xpc_activate_mq_uv;
 static struct xpc_gru_mq_uv *xpc_notify_mq_uv;
 
@@ -109,11 +113,8 @@ xpc_get_gru_mq_irq_uv(struct xpc_gru_mq_uv *mq, int cpu, char *irq_name)
 #if defined CONFIG_X86_64
         mq->irq = uv_setup_irq(irq_name, cpu, mq->mmr_blade, mq->mmr_offset,
                         UV_AFFINITY_CPU);
-        if (mq->irq < 0) {
-                dev_err(xpc_part, "uv_setup_irq() returned error=%d\n",
-                        -mq->irq);
+        if (mq->irq < 0)
                 return mq->irq;
-        }
 
         mq->mmr_value = uv_read_global_mmr64(mmr_pnode, mq->mmr_offset);
 
@@ -238,8 +239,9 @@ xpc_create_gru_mq_uv(unsigned int mq_size, int cpu, char *irq_name,
         mq->mmr_blade = uv_cpu_to_blade_id(cpu);
 
         nid = cpu_to_node(cpu);
-        page = alloc_pages_exact_node(nid, GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
-                                pg_order);
+        page = alloc_pages_exact_node(nid,
+                                      GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
+                                      pg_order);
         if (page == NULL) {
                 dev_err(xpc_part, "xpc_create_gru_mq_uv() failed to alloc %d "
                         "bytes of memory on nid=%d for GRU mq\n", mq_size, nid);
@@ -1731,9 +1733,50 @@ static struct xpc_arch_operations xpc_arch_ops_uv = {
         .notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_uv,
 };
 
+static int
+xpc_init_mq_node(int nid)
+{
+        int cpu;
+
+        get_online_cpus();
+
+        for_each_cpu(cpu, cpumask_of_node(nid)) {
+                xpc_activate_mq_uv =
+                        xpc_create_gru_mq_uv(XPC_ACTIVATE_MQ_SIZE_UV, nid,
+                                             XPC_ACTIVATE_IRQ_NAME,
+                                             xpc_handle_activate_IRQ_uv);
+                if (!IS_ERR(xpc_activate_mq_uv))
+                        break;
+        }
+        if (IS_ERR(xpc_activate_mq_uv)) {
+                put_online_cpus();
+                return PTR_ERR(xpc_activate_mq_uv);
+        }
+
+        for_each_cpu(cpu, cpumask_of_node(nid)) {
+                xpc_notify_mq_uv =
+                        xpc_create_gru_mq_uv(XPC_NOTIFY_MQ_SIZE_UV, nid,
+                                             XPC_NOTIFY_IRQ_NAME,
+                                             xpc_handle_notify_IRQ_uv);
+                if (!IS_ERR(xpc_notify_mq_uv))
+                        break;
+        }
+        if (IS_ERR(xpc_notify_mq_uv)) {
+                xpc_destroy_gru_mq_uv(xpc_activate_mq_uv);
+                put_online_cpus();
+                return PTR_ERR(xpc_notify_mq_uv);
+        }
+
+        put_online_cpus();
+        return 0;
+}
+
 int
 xpc_init_uv(void)
 {
+        int nid;
+        int ret = 0;
+
         xpc_arch_ops = xpc_arch_ops_uv;
 
         if (sizeof(struct xpc_notify_mq_msghdr_uv) > XPC_MSG_HDR_MAX_SIZE) {
@@ -1742,21 +1785,21 @@ xpc_init_uv(void)
                 return -E2BIG;
         }
 
-        xpc_activate_mq_uv = xpc_create_gru_mq_uv(XPC_ACTIVATE_MQ_SIZE_UV, 0,
-                                                  XPC_ACTIVATE_IRQ_NAME,
-                                                  xpc_handle_activate_IRQ_uv);
-        if (IS_ERR(xpc_activate_mq_uv))
-                return PTR_ERR(xpc_activate_mq_uv);
+        if (xpc_mq_node < 0)
+                for_each_online_node(nid) {
+                        ret = xpc_init_mq_node(nid);
 
-        xpc_notify_mq_uv = xpc_create_gru_mq_uv(XPC_NOTIFY_MQ_SIZE_UV, 0,
-                                                XPC_NOTIFY_IRQ_NAME,
-                                                xpc_handle_notify_IRQ_uv);
-        if (IS_ERR(xpc_notify_mq_uv)) {
-                xpc_destroy_gru_mq_uv(xpc_activate_mq_uv);
-                return PTR_ERR(xpc_notify_mq_uv);
-        }
+                        if (!ret)
+                                break;
+                }
+        else
+                ret = xpc_init_mq_node(xpc_mq_node);
 
-        return 0;
+        if (ret < 0)
+                dev_err(xpc_part, "xpc_init_mq_node() returned error=%d\n",
+                        -ret);
+
+        return ret;
 }
 
 void
@@ -1765,3 +1808,6 @@ xpc_exit_uv(void)
         xpc_destroy_gru_mq_uv(xpc_notify_mq_uv);
         xpc_destroy_gru_mq_uv(xpc_activate_mq_uv);
 }
+
+module_param(xpc_mq_node, int, 0);
+MODULE_PARM_DESC(xpc_mq_node, "Node number on which to allocate message queues.");
diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index 722246cf20ab..5d44252b7342 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -435,6 +435,9 @@ static void tsi721_db_dpc(struct work_struct *work)
                                 " info %4.4x\n", DBELL_SID(idb.bytes),
                                 DBELL_TID(idb.bytes), DBELL_INF(idb.bytes));
                 }
+
+                wr_ptr = ioread32(priv->regs +
+                                  TSI721_IDQ_WP(IDB_QUEUE)) % IDB_QSIZE;
         }
 
         iowrite32(rd_ptr & (IDB_QSIZE - 1),
@@ -445,6 +448,10 @@ static void tsi721_db_dpc(struct work_struct *work)
         regval |= TSI721_SR_CHINT_IDBQRCV;
         iowrite32(regval,
                 priv->regs + TSI721_SR_CHINTE(IDB_QUEUE));
+
+        wr_ptr = ioread32(priv->regs + TSI721_IDQ_WP(IDB_QUEUE)) % IDB_QSIZE;
+        if (wr_ptr != rd_ptr)
+                schedule_work(&priv->idb_work);
 }
 
 /**
@@ -2212,7 +2219,7 @@ static int __devinit tsi721_probe(struct pci_dev *pdev,
                                   const struct pci_device_id *id)
 {
         struct tsi721_device *priv;
-        int i, cap;
+        int cap;
         int err;
         u32 regval;
 
@@ -2232,12 +2239,15 @@ static int __devinit tsi721_probe(struct pci_dev *pdev,
         priv->pdev = pdev;
 
 #ifdef DEBUG
+        {
+        int i;
         for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
                 dev_dbg(&pdev->dev, "res[%d] @ 0x%llx (0x%lx, 0x%lx)\n",
                         i, (unsigned long long)pci_resource_start(pdev, i),
                         (unsigned long)pci_resource_len(pdev, i),
                         pci_resource_flags(pdev, i));
         }
+        }
 #endif
         /*
          * Verify BAR configuration
diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c
index 836118795c0b..13e4df63974f 100644
--- a/drivers/rtc/rtc-pcf2123.c
+++ b/drivers/rtc/rtc-pcf2123.c
@@ -43,6 +43,7 @@
 #include <linux/rtc.h>
 #include <linux/spi/spi.h>
 #include <linux/module.h>
+#include <linux/sysfs.h>
 
 #define DRV_VERSION "0.6"
 
@@ -292,6 +293,7 @@ static int __devinit pcf2123_probe(struct spi_device *spi)
         pdata->rtc = rtc;
 
         for (i = 0; i < 16; i++) {
+                sysfs_attr_init(&pdata->regs[i].attr.attr);
                 sprintf(pdata->regs[i].name, "%1x", i);
                 pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
                 pdata->regs[i].attr.attr.name = pdata->regs[i].name;
diff --git a/drivers/rtc/rtc-rs5c348.c b/drivers/rtc/rtc-rs5c348.c
index 77074ccd2850..fd5c7af04ae5 100644
--- a/drivers/rtc/rtc-rs5c348.c
+++ b/drivers/rtc/rtc-rs5c348.c
@@ -122,9 +122,12 @@ rs5c348_rtc_read_time(struct device *dev, struct rtc_time *tm)
         tm->tm_min = bcd2bin(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
         tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
         if (!pdata->rtc_24h) {
-                tm->tm_hour %= 12;
-                if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM)
+                if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM) {
+                        tm->tm_hour -= 20;
+                        tm->tm_hour %= 12;
                         tm->tm_hour += 12;
+                } else
+                        tm->tm_hour %= 12;
         }
         tm->tm_wday = bcd2bin(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
         tm->tm_mday = bcd2bin(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 133ddcf83397..ef658147e4e8 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -22,7 +22,7 @@ extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
 extern int fragmentation_index(struct zone *zone, unsigned int order);
 extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
                         int order, gfp_t gfp_mask, nodemask_t *mask,
-                        bool sync);
+                        bool sync, bool *contended);
 extern int compact_pgdat(pg_data_t *pgdat, int order);
 extern unsigned long compaction_suitable(struct zone *zone, int order);
 
@@ -64,7 +64,7 @@ static inline bool compaction_deferred(struct zone *zone, int order)
 #else
 static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
                         int order, gfp_t gfp_mask, nodemask_t *nodemask,
-                        bool sync)
+                        bool sync, bool *contended)
 {
         return COMPACT_CONTINUE;
 }
diff --git a/include/linux/string.h b/include/linux/string.h
index ffe0442e18d2..b9178812d9df 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -144,8 +144,8 @@ static inline bool strstarts(const char *str, const char *prefix)
 {
         return strncmp(str, prefix, strlen(prefix)) == 0;
 }
-#endif
 
 extern size_t memweight(const void *ptr, size_t bytes);
 
+#endif /* __KERNEL__ */
 #endif /* _LINUX_STRING_H_ */
diff --git a/mm/compaction.c b/mm/compaction.c
index e78cb9688421..7fcd3a52e68d 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -51,6 +51,47 @@ static inline bool migrate_async_suitable(int migratetype)
 }
 
 /*
+ * Compaction requires the taking of some coarse locks that are potentially
+ * very heavily contended. Check if the process needs to be scheduled or
+ * if the lock is contended. For async compaction, back out in the event
+ * if contention is severe. For sync compaction, schedule.
+ *
+ * Returns true if the lock is held.
+ * Returns false if the lock is released and compaction should abort
+ */
+static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags,
+                                      bool locked, struct compact_control *cc)
+{
+        if (need_resched() || spin_is_contended(lock)) {
+                if (locked) {
+                        spin_unlock_irqrestore(lock, *flags);
+                        locked = false;
+                }
+
+                /* async aborts if taking too long or contended */
+                if (!cc->sync) {
+                        if (cc->contended)
+                                *cc->contended = true;
+                        return false;
+                }
+
+                cond_resched();
+                if (fatal_signal_pending(current))
+                        return false;
+        }
+
+        if (!locked)
+                spin_lock_irqsave(lock, *flags);
+        return true;
+}
+
+static inline bool compact_trylock_irqsave(spinlock_t *lock,
+                        unsigned long *flags, struct compact_control *cc)
+{
+        return compact_checklock_irqsave(lock, flags, false, cc);
+}
+
+/*
  * Isolate free pages onto a private freelist. Caller must hold zone->lock.
  * If @strict is true, will abort returning 0 on any invalid PFNs or non-free
  * pages inside of the pageblock (even though it may still end up isolating
@@ -173,7 +214,7 @@ isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn)
 }
 
 /* Update the number of anon and file isolated pages in the zone */
-static void acct_isolated(struct zone *zone, struct compact_control *cc)
+static void acct_isolated(struct zone *zone, bool locked, struct compact_control *cc)
 {
         struct page *page;
         unsigned int count[2] = { 0, };
@@ -181,8 +222,14 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc)
         list_for_each_entry(page, &cc->migratepages, lru)
                 count[!!page_is_file_cache(page)]++;
 
-        __mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]);
-        __mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]);
+        /* If locked we can use the interrupt unsafe versions */
+        if (locked) {
+                __mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]);
+                __mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]);
+        } else {
+                mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]);
+                mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]);
+        }
 }
 
 /* Similar to reclaim, but different enough that they don't share logic */
@@ -228,6 +275,8 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
         struct list_head *migratelist = &cc->migratepages;
         isolate_mode_t mode = 0;
         struct lruvec *lruvec;
+        unsigned long flags;
+        bool locked;
 
         /*
          * Ensure that there are not too many pages isolated from the LRU
@@ -247,25 +296,22 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
 
         /* Time to isolate some pages for migration */
         cond_resched();
-        spin_lock_irq(&zone->lru_lock);
+        spin_lock_irqsave(&zone->lru_lock, flags);
+        locked = true;
         for (; low_pfn < end_pfn; low_pfn++) {
                 struct page *page;
-                bool locked = true;
 
                 /* give a chance to irqs before checking need_resched() */
                 if (!((low_pfn+1) % SWAP_CLUSTER_MAX)) {
-                        spin_unlock_irq(&zone->lru_lock);
+                        spin_unlock_irqrestore(&zone->lru_lock, flags);
                         locked = false;
                 }
-                if (need_resched() || spin_is_contended(&zone->lru_lock)) {
-                        if (locked)
-                                spin_unlock_irq(&zone->lru_lock);
-                        cond_resched();
-                        spin_lock_irq(&zone->lru_lock);
-                        if (fatal_signal_pending(current))
-                                break;
-                } else if (!locked)
-                        spin_lock_irq(&zone->lru_lock);
+
+                /* Check if it is ok to still hold the lock */
+                locked = compact_checklock_irqsave(&zone->lru_lock, &flags,
+                                                                locked, cc);
+                if (!locked)
+                        break;
 
                 /*
                  * migrate_pfn does not necessarily start aligned to a
@@ -349,9 +395,10 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
                 }
         }
 
-        acct_isolated(zone, cc);
+        acct_isolated(zone, locked, cc);
 
-        spin_unlock_irq(&zone->lru_lock);
+        if (locked)
+                spin_unlock_irqrestore(&zone->lru_lock, flags);
 
         trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);
 
@@ -384,6 +431,20 @@ static bool suitable_migration_target(struct page *page)
 }
 
 /*
+ * Returns the start pfn of the last page block in a zone.  This is the starting
+ * point for full compaction of a zone.  Compaction searches for free pages from
+ * the end of each zone, while isolate_freepages_block scans forward inside each
+ * page block.
+ */
+static unsigned long start_free_pfn(struct zone *zone)
+{
+        unsigned long free_pfn;
+        free_pfn = zone->zone_start_pfn + zone->spanned_pages;
+        free_pfn &= ~(pageblock_nr_pages-1);
+        return free_pfn;
+}
+
+/*
  * Based on information in the current compact_control, find blocks
  * suitable for isolating free pages from and then isolate them.
  */
@@ -422,17 +483,6 @@ static void isolate_freepages(struct zone *zone,
                                         pfn -= pageblock_nr_pages) {
                 unsigned long isolated;
 
-                /*
-                 * Skip ahead if another thread is compacting in the area
-                 * simultaneously. If we wrapped around, we can only skip
-                 * ahead if zone->compact_cached_free_pfn also wrapped to
-                 * above our starting point.
-                 */
-                if (cc->order > 0 && (!cc->wrapped ||
-                                      zone->compact_cached_free_pfn >
-                                      cc->start_free_pfn))
-                        pfn = min(pfn, zone->compact_cached_free_pfn);
-
                 if (!pfn_valid(pfn))
                         continue;
 
@@ -458,7 +508,16 @@ static void isolate_freepages(struct zone *zone,
                  * are disabled
                  */
                 isolated = 0;
-                spin_lock_irqsave(&zone->lock, flags);
+
+                /*
+                 * The zone lock must be held to isolate freepages. This
+                 * unfortunately this is a very coarse lock and can be
+                 * heavily contended if there are parallel allocations
+                 * or parallel compactions. For async compaction do not
+                 * spin on the lock
+                 */
+                if (!compact_trylock_irqsave(&zone->lock, &flags, cc))
+                        break;
                 if (suitable_migration_target(page)) {
                         end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn);
                         isolated = isolate_freepages_block(pfn, end_pfn,
@@ -474,7 +533,15 @@ static void isolate_freepages(struct zone *zone,
                  */
                 if (isolated) {
                         high_pfn = max(high_pfn, pfn);
-                        if (cc->order > 0)
+
+                        /*
+                         * If the free scanner has wrapped, update
+                         * compact_cached_free_pfn to point to the highest
+                         * pageblock with free pages. This reduces excessive
+                         * scanning of full pageblocks near the end of the
+                         * zone
+                         */
+                        if (cc->order > 0 && cc->wrapped)
                                 zone->compact_cached_free_pfn = high_pfn;
                 }
         }
@@ -484,6 +551,11 @@ static void isolate_freepages(struct zone *zone,
 
         cc->free_pfn = high_pfn;
         cc->nr_freepages = nr_freepages;
+
+        /* If compact_cached_free_pfn is reset then set it now */
+        if (cc->order > 0 && !cc->wrapped &&
+                        zone->compact_cached_free_pfn == start_free_pfn(zone))
+                zone->compact_cached_free_pfn = high_pfn;
 }
 
 /*
@@ -570,20 +642,6 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
         return ISOLATE_SUCCESS;
 }
 
-/*
- * Returns the start pfn of the last page block in a zone.  This is the starting
- * point for full compaction of a zone.  Compaction searches for free pages from
- * the end of each zone, while isolate_freepages_block scans forward inside each
- * page block.
- */
-static unsigned long start_free_pfn(struct zone *zone)
-{
-        unsigned long free_pfn;
-        free_pfn = zone->zone_start_pfn + zone->spanned_pages;
-        free_pfn &= ~(pageblock_nr_pages-1);
-        return free_pfn;
-}
-
 static int compact_finished(struct zone *zone,
                             struct compact_control *cc)
 {
@@ -771,7 +829,7 @@ out:
 
 static unsigned long compact_zone_order(struct zone *zone,
                                  int order, gfp_t gfp_mask,
-                                 bool sync)
+                                 bool sync, bool *contended)
 {
         struct compact_control cc = {
                 .nr_freepages = 0,
@@ -780,6 +838,7 @@ static unsigned long compact_zone_order(struct zone *zone,
                 .migratetype = allocflags_to_migratetype(gfp_mask),
                 .zone = zone,
                 .sync = sync,
+                .contended = contended,
         };
         INIT_LIST_HEAD(&cc.freepages);
         INIT_LIST_HEAD(&cc.migratepages);
@@ -801,7 +860,7 @@ int sysctl_extfrag_threshold = 500;
  */
 unsigned long try_to_compact_pages(struct zonelist *zonelist,
                         int order, gfp_t gfp_mask, nodemask_t *nodemask,
-                        bool sync)
+                        bool sync, bool *contended)
 {
         enum zone_type high_zoneidx = gfp_zone(gfp_mask);
         int may_enter_fs = gfp_mask & __GFP_FS;
@@ -825,7 +884,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
                                                                 nodemask) {
                 int status;
 
-                status = compact_zone_order(zone, order, gfp_mask, sync);
+                status = compact_zone_order(zone, order, gfp_mask, sync,
+                                                contended);
                 rc = max(status, rc);
 
                 /* If a normal allocation would succeed, stop compacting */
@@ -861,7 +921,7 @@ static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
                 if (cc->order > 0) {
                         int ok = zone_watermark_ok(zone, cc->order,
                                                 low_wmark_pages(zone), 0, 0);
-                        if (ok && cc->order > zone->compact_order_failed)
+                        if (ok && cc->order >= zone->compact_order_failed)
                                 zone->compact_order_failed = cc->order + 1;
                         /* Currently async compaction is never deferred. */
                         else if (!ok && cc->sync)
diff --git a/mm/internal.h b/mm/internal.h
index 3314f79d775a..b8c91b342e24 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -130,6 +130,7 @@ struct compact_control {
         int order;                      /* order a direct compactor needs */
         int migratetype;                /* MOVABLE, RECLAIMABLE etc */
         struct zone *zone;
+        bool *contended;                /* True if a lock was contended */
 };
 
 unsigned long
diff --git a/mm/mmap.c b/mm/mmap.c
index e3e86914f11a..9adee9fc0d8a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2309,7 +2309,7 @@ void exit_mmap(struct mm_struct *mm)
         }
         vm_unacct_memory(nr_accounted);
 
-        BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);
+        WARN_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);
 }
 
 /* Insert vm structure into process list sorted by address
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 009ac285fea7..c66fb875104a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1928,6 +1928,17 @@ this_zone_full:
                 zlc_active = 0;
                 goto zonelist_scan;
         }
+
+        if (page)
+                /*
+                 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
+                 * necessary to allocate the page. The expectation is
+                 * that the caller is taking steps that will free more
+                 * memory. The caller should avoid the page being used
+                 * for !PFMEMALLOC purposes.
+                 */
+                page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
+
         return page;
 }
 
@@ -2091,7 +2102,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
         int migratetype, bool sync_migration,
-        bool *deferred_compaction,
+        bool *contended_compaction, bool *deferred_compaction,
         unsigned long *did_some_progress)
 {
         struct page *page;
@@ -2106,7 +2117,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 
         current->flags |= PF_MEMALLOC;
         *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
-                                                nodemask, sync_migration);
+                                                nodemask, sync_migration,
+                                                contended_compaction);
         current->flags &= ~PF_MEMALLOC;
         if (*did_some_progress != COMPACT_SKIPPED) {
 
@@ -2152,7 +2164,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
         int migratetype, bool sync_migration,
-        bool *deferred_compaction,
+        bool *contended_compaction, bool *deferred_compaction,
         unsigned long *did_some_progress)
 {
         return NULL;
@@ -2325,6 +2337,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
         unsigned long did_some_progress;
         bool sync_migration = false;
         bool deferred_compaction = false;
+        bool contended_compaction = false;
 
         /*
          * In the slowpath, we sanity check order to avoid ever trying to
@@ -2389,14 +2402,6 @@ rebalance:
                                 zonelist, high_zoneidx, nodemask,
                                 preferred_zone, migratetype);
                 if (page) {
-                        /*
-                         * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
-                         * necessary to allocate the page. The expectation is
-                         * that the caller is taking steps that will free more
-                         * memory. The caller should avoid the page being used
-                         * for !PFMEMALLOC purposes.
-                         */
-                        page->pfmemalloc = true;
                         goto got_pg;
                 }
         }
@@ -2422,6 +2427,7 @@ rebalance:
                                         nodemask,
                                         alloc_flags, preferred_zone,
                                         migratetype, sync_migration,
+                                        &contended_compaction,
                                         &deferred_compaction,
                                         &did_some_progress);
         if (page)
@@ -2431,10 +2437,11 @@ rebalance:
         /*
          * If compaction is deferred for high-order allocations, it is because
          * sync compaction recently failed. In this is the case and the caller
-         * has requested the system not be heavily disrupted, fail the
-         * allocation now instead of entering direct reclaim
+         * requested a movable allocation that does not heavily disrupt the
+         * system then fail the allocation instead of entering direct reclaim.
          */
-        if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD))
+        if ((deferred_compaction || contended_compaction) &&
+                                                (gfp_mask & __GFP_NO_KSWAPD))
                 goto nopage;
 
         /* Try direct reclaim and then allocating */
@@ -2505,6 +2512,7 @@ rebalance:
                                         nodemask,
                                         alloc_flags, preferred_zone,
                                         migratetype, sync_migration,
+                                        &contended_compaction,
                                         &deferred_compaction,
                                         &did_some_progress);
                 if (page)
@@ -2569,8 +2577,6 @@ retry_cpuset:
                 page = __alloc_pages_slowpath(gfp_mask, order,
                                 zonelist, high_zoneidx, nodemask,
                                 preferred_zone, migratetype);
-        else
-                page->pfmemalloc = false;
 
         trace_mm_page_alloc(page, order, gfp_mask, migratetype);
 
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 913d6bdfdda3..ca05ba217f5f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3016,7 +3016,8 @@ sub process {
                                         $herectx .= raw_line($linenr, $n) . "\n";
                                 }
 
-                                if (($stmts =~ tr/;/;/) == 1) {
+                                if (($stmts =~ tr/;/;/) == 1 &&
+                                    $stmts !~ /^\s*(if|while|for|switch)\b/) {
                                         WARN("SINGLE_STATEMENT_DO_WHILE_MACRO",
                                              "Single statement macros should not use a do {} while (0) loop\n" . "$herectx");
                                 }