diff options
| author | Dimitri Sivanich <sivanich@sgi.com> | 2011-10-31 20:09:46 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-01 15:26:54 -0400 |
| commit | 9116bc4fb2f96d4a3190932bf17088174da04401 (patch) | |
| tree | 7223f2374e39700a9ae6ddde4bdd645dc8b3daf0 | |
| parent | fbb41f55c42a4f4e708c9e9af926dc6227a5b52d (diff) | |
mm/vmstat.c: cache align vm_stat
commit a1cb2c60ddc98ff4e5246f410558805401ceee67 upstream.
Stable note: Not tracked on Bugzilla. This patch is known to make a big
difference to tmpfs performance on larger machines.
This was found to adversely affect tmpfs I/O performance.
Tests run on a 640 cpu UV system.
With 120 threads doing parallel writes, each to different tmpfs mounts:
No patch: ~300 MB/sec
With vm_stat alignment: ~430 MB/sec
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: Christoph Lameter <cl@gentwo.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
| -rw-r--r-- | mm/vmstat.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c index 20c18b7694b..6559013c5a1 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c | |||
| @@ -78,7 +78,7 @@ void vm_events_fold_cpu(int cpu) | |||
| 78 | * | 78 | * |
| 79 | * vm_stat contains the global counters | 79 | * vm_stat contains the global counters |
| 80 | */ | 80 | */ |
| 81 | atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; | 81 | atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp; |
| 82 | EXPORT_SYMBOL(vm_stat); | 82 | EXPORT_SYMBOL(vm_stat); |
| 83 | 83 | ||
| 84 | #ifdef CONFIG_SMP | 84 | #ifdef CONFIG_SMP |