From addb9efebb2ee2202d324e75b593b39868528f68 Mon Sep 17 00:00:00 2001
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Date: Sat, 18 Oct 2008 20:28:10 -0700
Subject: [PATCH] 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: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/memcontrol.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6f8b5b3b38b2..10846b9656aa 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -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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