3 files changed, 13 insertions, 58 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 3303d1ba8e87..6b7b1a95944b 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -85,7 +85,7 @@ EXPORT_SYMBOL(vm_get_page_prot);
 int sysctl_overcommit_memory = OVERCOMMIT_GUESS;  /* heuristic overcommit */
 int sysctl_overcommit_ratio = 50;       /* default is 50% */
 int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
-atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0);
+struct percpu_counter vm_committed_as;
 
 /*
  * Check that a process has enough memory to allocate a new virtual
@@ -179,11 +179,7 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
         if (mm)
                 allowed -= mm->total_vm / 32;
 
-        /*
-         * cast `allowed' as a signed long because vm_committed_space
-         * sometimes has a negative value
-         */
-        if (atomic_long_read(&vm_committed_space) < (long)allowed)
+        if (percpu_counter_read_positive(&vm_committed_as) < allowed)
                 return 0;
 error:
         vm_unacct_memory(pages);
@@ -2481,4 +2477,8 @@ void mm_drop_all_locks(struct mm_struct *mm)
  */
 void __init mmap_init(void)
 {
+        int ret;
+
+        ret = percpu_counter_init(&vm_committed_as, 0);
+        VM_BUG_ON(ret);
 }
diff --git a/mm/nommu.c b/mm/nommu.c
index 72eda4aee2cb..809998aa7b50 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -62,7 +62,7 @@ void *high_memory;
 struct page *mem_map;
 unsigned long max_mapnr;
 unsigned long num_physpages;
-atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0);
+struct percpu_counter vm_committed_as;
 int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
 int sysctl_overcommit_ratio = 50; /* default is 50% */
 int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
@@ -463,6 +463,10 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
  */
 void __init mmap_init(void)
 {
+        int ret;
+
+        ret = percpu_counter_init(&vm_committed_as, 0);
+        VM_BUG_ON(ret);
         vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC);
 }
 
@@ -1847,12 +1851,9 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
         if (mm)
                 allowed -= mm->total_vm / 32;
 
-        /*
-         * cast `allowed' as a signed long because vm_committed_space
-         * sometimes has a negative value
-         */
-        if (atomic_long_read(&vm_committed_space) < (long)allowed)
+        if (percpu_counter_read_positive(&vm_committed_as) < allowed)
                 return 0;
+
 error:
         vm_unacct_memory(pages);
 
diff --git a/mm/swap.c b/mm/swap.c
index bede23ce64ea..cb29ae5d33ab 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -491,49 +491,6 @@ unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping,
 
 EXPORT_SYMBOL(pagevec_lookup_tag);
 
-#ifdef CONFIG_SMP
-/*
- * We tolerate a little inaccuracy to avoid ping-ponging the counter between
- * CPUs
- */
-#define ACCT_THRESHOLD  max(16, NR_CPUS * 2)
-
-static DEFINE_PER_CPU(long, committed_space);
-
-void vm_acct_memory(long pages)
-{
-        long *local;
-
-        preempt_disable();
-        local = &__get_cpu_var(committed_space);
-        *local += pages;
-        if (*local > ACCT_THRESHOLD || *local < -ACCT_THRESHOLD) {
-                atomic_long_add(*local, &vm_committed_space);
-                *local = 0;
-        }
-        preempt_enable();
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/* Drop the CPU's cached committed space back into the central pool. */
-static int cpu_swap_callback(struct notifier_block *nfb,
-                             unsigned long action,
-                             void *hcpu)
-{
-        long *committed;
-
-        committed = &per_cpu(committed_space, (long)hcpu);
-        if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
-                atomic_long_add(*committed, &vm_committed_space);
-                *committed = 0;
-                drain_cpu_pagevecs((long)hcpu);
-        }
-        return NOTIFY_OK;
-}
-#endif /* CONFIG_HOTPLUG_CPU */
-#endif /* CONFIG_SMP */
-
 /*
  * Perform any setup for the swap system
  */
@@ -554,7 +511,4 @@ void __init swap_setup(void)
          * Right now other parts of the system means that we
          * _really_ don't want to cluster much more
          */
-#ifdef CONFIG_HOTPLUG_CPU
-        hotcpu_notifier(cpu_swap_callback, 0);
-#endif
 }