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Subject[PATCH] cache align vm_stat
Avoid false sharing of the vm_stat array.

This was found to adversely affect tmpfs I/O performance.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
---
mm/vmstat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/mm/vmstat.c
===================================================================
--- linux.orig/mm/vmstat.c
+++ linux/mm/vmstat.c
@@ -78,7 +78,7 @@ void vm_events_fold_cpu(int cpu)
*
* vm_stat contains the global counters
*/
-atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
+atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
EXPORT_SYMBOL(vm_stat);

#ifdef CONFIG_SMP

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