Commit addb9efe authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
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memcg: optimize per-cpu statistics 



Some obvious optimization to memcg.

I found mem_cgroup_charge_statistics() is a little big (in object) and
does unnecessary address calclation.  This patch is for optimization to
reduce the size of this function.

And res_counter_charge() is 'likely' to succeed.

Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5b4e655e

mm/memcontrol.c

+10 −8
Original line number Diff line number Diff line
@@ -66,11 +66,10 @@ struct mem_cgroup_stat { 
/*

 * For accounting under irq disable, no need for increment preempt count.

 */

static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat *stat,

static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,

		enum mem_cgroup_stat_index idx, int val)

{

	int cpu = smp_processor_id();

	stat->cpustat[cpu].count[idx] += val;

	stat->count[idx] += val;

}



static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
@@ -190,18 +189,21 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags, 
{

	int val = (charge)? 1 : -1;

	struct mem_cgroup_stat *stat = &mem->stat;

	struct mem_cgroup_stat_cpu *cpustat;



	VM_BUG_ON(!irqs_disabled());



	cpustat = &stat->cpustat[smp_processor_id()];

	if (flags & PAGE_CGROUP_FLAG_CACHE)

		__mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_CACHE, val);

		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);

	else

		__mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val);

		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);



	if (charge)

		__mem_cgroup_stat_add_safe(stat,

		__mem_cgroup_stat_add_safe(cpustat,

				MEM_CGROUP_STAT_PGPGIN_COUNT, 1);

	else

		__mem_cgroup_stat_add_safe(stat,

		__mem_cgroup_stat_add_safe(cpustat,

				MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);

}
@@ -558,7 +560,7 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, 
		css_get(&memcg->css);

	}



	while (res_counter_charge(&mem->res, PAGE_SIZE)) {

	while (unlikely(res_counter_charge(&mem->res, PAGE_SIZE))) {

		if (!(gfp_mask & __GFP_WAIT))

			goto out;

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