dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

mm: memcg: shorten preempt-disabled section around event checks 

Only the ratelimit checks themselves have to run with preemption
disabled, the resulting actions - checking for usage thresholds,
updating the soft limit tree - can and should run with preemption
enabled.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reported-by: Yong Zhang <yong.zhang0@gmail.com>
Tested-by: Yong Zhang <yong.zhang0@gmail.com>
Reported-by: Luis Henriques <henrix@camandro.org>
Tested-by: Luis Henriques <henrix@camandro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2012-01-12 17:18:23 -08:00 committed by Linus Torvalds
parent e94c8a9cbc
commit f53d7ce32e
1 changed files with 38 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

79
mm/memcontrol.c
View File

@ -748,37 +748,32 @@ static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
return total;
}
static bool __memcg_event_check(struct mem_cgroup *memcg, int target)
static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
enum mem_cgroup_events_target target)
{
unsigned long val, next;
val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
next = __this_cpu_read(memcg->stat->targets[target]);
/* from time_after() in jiffies.h */
return ((long)next - (long)val < 0);
}
static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target)
{
unsigned long val, next;
val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
switch (target) {
case MEM_CGROUP_TARGET_THRESH:
next = val + THRESHOLDS_EVENTS_TARGET;
break;
case MEM_CGROUP_TARGET_SOFTLIMIT:
next = val + SOFTLIMIT_EVENTS_TARGET;
break;
case MEM_CGROUP_TARGET_NUMAINFO:
next = val + NUMAINFO_EVENTS_TARGET;
break;
default:
return;
if ((long)next - (long)val < 0) {
switch (target) {
case MEM_CGROUP_TARGET_THRESH:
next = val + THRESHOLDS_EVENTS_TARGET;
break;
case MEM_CGROUP_TARGET_SOFTLIMIT:
next = val + SOFTLIMIT_EVENTS_TARGET;
break;
case MEM_CGROUP_TARGET_NUMAINFO:
next = val + NUMAINFO_EVENTS_TARGET;
break;
default:
break;
}
__this_cpu_write(memcg->stat->targets[target], next);
return true;
}
__this_cpu_write(memcg->stat->targets[target], next);
return false;
}
/*
@ -789,25 +784,27 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
{
preempt_disable();
/* threshold event is triggered in finer grain than soft limit */
if (unlikely(__memcg_event_check(memcg, MEM_CGROUP_TARGET_THRESH))) {
mem_cgroup_threshold(memcg);
__mem_cgroup_target_update(memcg, MEM_CGROUP_TARGET_THRESH);
if (unlikely(__memcg_event_check(memcg,
MEM_CGROUP_TARGET_SOFTLIMIT))) {
mem_cgroup_update_tree(memcg, page);
__mem_cgroup_target_update(memcg,
MEM_CGROUP_TARGET_SOFTLIMIT);
}
if (unlikely(mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_THRESH))) {
bool do_softlimit, do_numainfo;
do_softlimit = mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_SOFTLIMIT);
#if MAX_NUMNODES > 1
if (unlikely(__memcg_event_check(memcg,
MEM_CGROUP_TARGET_NUMAINFO))) {
atomic_inc(&memcg->numainfo_events);
__mem_cgroup_target_update(memcg,
MEM_CGROUP_TARGET_NUMAINFO);
}
do_numainfo = mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_NUMAINFO);
#endif
}
preempt_enable();
preempt_enable();
mem_cgroup_threshold(memcg);
if (unlikely(do_softlimit))
mem_cgroup_update_tree(memcg, page);
#if MAX_NUMNODES > 1
if (unlikely(do_numainfo))
atomic_inc(&memcg->numainfo_events);
#endif
} else
preempt_enable();
}
struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)