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| author | Christoph Lameter <cl@linux.com> | 2010-12-06 11:40:02 -0600 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-12-17 15:18:04 +0100 |
| commit | 908ee0f122bf2a67414854af5b90c6621d186a71 (patch) | |
| tree | 5394b0b65dada76fed551d44ca0561fe5b7ac839 /mm/vmstat.c | |
| parent | 275c8b93288ef0c2281e414e069ea8ed4bad03f7 (diff) | |
| download | lwn-908ee0f122bf2a67414854af5b90c6621d186a71.tar.gz lwn-908ee0f122bf2a67414854af5b90c6621d186a71.zip | |
vmstat: Use this_cpu_inc_return for vm statistics
this_cpu_inc_return() saves us a memory access there. Code
size does not change.
V1->V2:
- Fixed the location of the __per_cpu pointer attributes
- Sparse checked
V2->V3:
- Move fixes to __percpu attribute usage to earlier patch
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'mm/vmstat.c')
| -rw-r--r-- | mm/vmstat.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c index 3ad909d9600f..f9a7bc89fd10 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -227,9 +227,7 @@ void __inc_zone_state(struct zone *zone, enum zone_stat_item item) s8 __percpu *p = pcp->vm_stat_diff + item; s8 v, t; - __this_cpu_inc(*p); - - v = __this_cpu_read(*p); + v = __this_cpu_inc_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v > t)) { s8 overstep = t >> 1; @@ -251,9 +249,7 @@ void __dec_zone_state(struct zone *zone, enum zone_stat_item item) s8 __percpu *p = pcp->vm_stat_diff + item; s8 v, t; - __this_cpu_dec(*p); - - v = __this_cpu_read(*p); + v = __this_cpu_dec_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v < - t)) { s8 overstep = t >> 1; |