Messages in this thread Patch in this message | | | Date | Mon, 24 Oct 2011 11:10:35 -0500 | From | Dimitri Sivanich <> | Subject | [PATCH] cache align vm_stat |
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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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