7 files changed, 56 insertions, 45 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index dec8249e972d..8778f58880c4 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1761,7 +1761,6 @@ static void gather_stats(struct page *page, void *private, int pte_dirty)
                 md->mapcount_max = count;
 
         md->node[page_to_nid(page)]++;
-        cond_resched();
 }
 
 #ifdef CONFIG_HUGETLB_PAGE
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 78747afad6b0..042e6436c3ee 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -46,15 +46,25 @@
 unsigned long badness(struct task_struct *p, unsigned long uptime)
 {
         unsigned long points, cpu_time, run_time, s;
-        struct list_head *tsk;
+        struct mm_struct *mm;
+        struct task_struct *child;
 
-        if (!p->mm)
+        task_lock(p);
+        mm = p->mm;
+        if (!mm) {
+                task_unlock(p);
                 return 0;
+        }
 
         /*
          * The memory size of the process is the basis for the badness.
          */
-        points = p->mm->total_vm;
+        points = mm->total_vm;
+
+        /*
+         * After this unlock we can no longer dereference local variable `mm'
+         */
+        task_unlock(p);
 
         /*
          * Processes which fork a lot of child processes are likely
@@ -64,11 +74,11 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
          * child is eating the vast majority of memory, adding only half
          * to the parents will make the child our kill candidate of choice.
          */
-        list_for_each(tsk, &p->children) {
-                struct task_struct *chld;
-                chld = list_entry(tsk, struct task_struct, sibling);
-                if (chld->mm != p->mm && chld->mm)
-                        points += chld->mm->total_vm/2 + 1;
+        list_for_each_entry(child, &p->children, sibling) {
+                task_lock(child);
+                if (child->mm != mm && child->mm)
+                        points += child->mm->total_vm/2 + 1;
+                task_unlock(child);
         }
 
         /*
@@ -244,17 +254,24 @@ static void __oom_kill_task(task_t *p, const char *message)
         force_sig(SIGKILL, p);
 }
 
-static struct mm_struct *oom_kill_task(task_t *p, const char *message)
+static int oom_kill_task(task_t *p, const char *message)
 {
-        struct mm_struct *mm = get_task_mm(p);
+        struct mm_struct *mm;
         task_t * g, * q;
 
-        if (!mm)
-                return NULL;
-        if (mm == &init_mm) {
-                mmput(mm);
-                return NULL;
-        }
+        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.
+         *
+         * Furthermore, even if mm contains a non-NULL value, p->mm may
+         * 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 || mm == &init_mm)
+                return 1;
 
         __oom_kill_task(p, message);
         /*
@@ -266,13 +283,12 @@ static struct mm_struct *oom_kill_task(task_t *p, const char *message)
                         __oom_kill_task(q, message);
         while_each_thread(g, q);
 
-        return mm;
+        return 0;
 }
 
-static struct mm_struct *oom_kill_process(struct task_struct *p,
-                                unsigned long points, const char *message)
+static int oom_kill_process(struct task_struct *p, unsigned long points,
+                const char *message)
 {
-        struct mm_struct *mm;
         struct task_struct *c;
         struct list_head *tsk;
 
@@ -283,9 +299,8 @@ static struct mm_struct *oom_kill_process(struct task_struct *p,
                 c = list_entry(tsk, struct task_struct, sibling);
                 if (c->mm == p->mm)
                         continue;
-                mm = oom_kill_task(c, message);
-                if (mm)
-                        return mm;
+                if (!oom_kill_task(c, message))
+                        return 0;
         }
         return oom_kill_task(p, message);
 }
@@ -300,7 +315,6 @@ static struct mm_struct *oom_kill_process(struct task_struct *p,
  */
 void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 {
-        struct mm_struct *mm = NULL;
         task_t *p;
         unsigned long points = 0;
 
@@ -320,12 +334,12 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
          */
         switch (constrained_alloc(zonelist, gfp_mask)) {
         case CONSTRAINT_MEMORY_POLICY:
-                mm = oom_kill_process(current, points,
+                oom_kill_process(current, points,
                                 "No available memory (MPOL_BIND)");
                 break;
 
         case CONSTRAINT_CPUSET:
-                mm = oom_kill_process(current, points,
+                oom_kill_process(current, points,
                                 "No available memory in cpuset");
                 break;
 
@@ -347,8 +361,7 @@ retry:
                         panic("Out of memory and no killable processes...\n");
                 }
 
-                mm = oom_kill_process(p, points, "Out of memory");
-                if (!mm)
+                if (oom_kill_process(p, points, "Out of memory"))
                         goto retry;
 
                 break;
@@ -357,8 +370,6 @@ retry:
 out:
         read_unlock(&tasklist_lock);
         cpuset_unlock();
-        if (mm)
-                mmput(mm);
 
         /*
          * Give "p" a good chance of killing itself before we
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 97d6827c7d66..ea77c999047e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -232,11 +232,13 @@ static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
  * zone->lock is already acquired when we use these.
  * So, we don't need atomic page->flags operations here.
  */
-static inline unsigned long page_order(struct page *page) {
+static inline unsigned long page_order(struct page *page)
+{
         return page_private(page);
 }
 
-static inline void set_page_order(struct page *page, int order) {
+static inline void set_page_order(struct page *page, int order)
+{
         set_page_private(page, order);
         __SetPageBuddy(page);
 }
@@ -299,9 +301,9 @@ static inline int page_is_buddy(struct page *page, int order)
 
         if (PageBuddy(page) && page_order(page) == order) {
                 BUG_ON(page_count(page) != 0);
-               return 1;
+                return 1;
         }
-       return 0;
+        return 0;
 }
 
 /*
@@ -1960,7 +1962,7 @@ static inline void free_zone_pagesets(int cpu)
         }
 }
 
-static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
+static int pageset_cpuup_callback(struct notifier_block *nfb,
                 unsigned long action,
                 void *hcpu)
 {
diff --git a/mm/shmem.c b/mm/shmem.c
index 37eaf42ed2c6..4c5e68e4e9ae 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -46,6 +46,8 @@
 #include <linux/mempolicy.h>
 #include <linux/namei.h>
 #include <linux/ctype.h>
+#include <linux/migrate.h>
+
 #include <asm/uaccess.h>
 #include <asm/div64.h>
 #include <asm/pgtable.h>
@@ -2173,6 +2175,7 @@ static struct address_space_operations shmem_aops = {
         .prepare_write  = shmem_prepare_write,
         .commit_write   = simple_commit_write,
 #endif
+        .migratepage    = migrate_page,
 };
 
 static struct file_operations shmem_file_operations = {
diff --git a/mm/slab.c b/mm/slab.c
index e6ef9bd52335..af5c5237e11a 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1036,7 +1036,7 @@ static inline void free_alien_cache(struct array_cache **ac_ptr)
 
 #endif
 
-static int __devinit cpuup_callback(struct notifier_block *nfb,
+static int cpuup_callback(struct notifier_block *nfb,
                                     unsigned long action, void *hcpu)
 {
         long cpu = (long)hcpu;
diff --git a/mm/slob.c b/mm/slob.c
index 9bcc7e2cabfd..a68255ba4553 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -354,9 +354,7 @@ void *__alloc_percpu(size_t size)
         if (!pdata)
                 return NULL;
 
-        for (i = 0; i < NR_CPUS; i++) {
-                if (!cpu_possible(i))
-                        continue;
+        for_each_possible_cpu(i) {
                 pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
                 if (!pdata->ptrs[i])
                         goto unwind_oom;
@@ -383,11 +381,9 @@ free_percpu(const void *objp)
         int i;
         struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp);
 
-        for (i = 0; i < NR_CPUS; i++) {
-                if (!cpu_possible(i))
-                        continue;
+        for_each_possible_cpu(i)
                 kfree(p->ptrs[i]);
-        }
+
         kfree(p);
 }
 EXPORT_SYMBOL(free_percpu);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index acdf001d6941..4649a63a8cb6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1328,7 +1328,7 @@ repeat:
    not required for correctness.  So if the last cpu in a node goes
    away, we get changed to run anywhere: as the first one comes back,
    restore their cpu bindings. */
-static int __devinit cpu_callback(struct notifier_block *nfb,
+static int cpu_callback(struct notifier_block *nfb,
                                   unsigned long action, void *hcpu)
 {
         pg_data_t *pgdat;