vmstat: Use this_cpu_inc_return for vm statistics (908ee0f1) · Commits · 戴 / test

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>

mm/vmstat.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -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;

Admin message