}
EXPORT_SYMBOL(vm_get_page_prot);
-int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
-int sysctl_overcommit_ratio = 50; /* default is 50% */
+int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */
+int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */
int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
-struct percpu_counter vm_committed_as;
+/*
+ * Make sure vm_committed_as in one cacheline and not cacheline shared with
+ * other variables. It can be updated by several CPUs frequently.
+ */
+struct percpu_counter vm_committed_as ____cacheline_aligned_in_smp;
/*
* Check that a process has enough memory to allocate a new virtual
* lock may be shared between many sibling processes. Skipping
* the lock for brk adjustments makes a difference sometimes.
*/
- if (vma->anon_vma && (insert || importer || start != vma->vm_start)) {
+ if (vma->anon_vma && (importer || start != vma->vm_start)) {
anon_vma = vma->anon_vma;
anon_vma_lock(anon_vma);
}