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authorMichal Hocko <mhocko@suse.cz>2013-07-31 13:53:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-31 14:41:03 -0700
commit22f2020f84c6da2dd0acb2dce12e39e59ff7c8be (patch)
tree34188bc4df41de78fbbc4c45c8b913ea8f7f7761
parent62e32ac3505a0cab1c5ef8ea2c0eab3b26ed855f (diff)
vmpressure: change vmpressure::sr_lock to spinlock
There is nothing that can sleep inside critical sections protected by this lock and those sections are really small so there doesn't make much sense to use mutex for them. Change the log to a spinlock Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-by: Tejun Heo <tj@kernel.org> Cc: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Li Zefan <lizefan@huawei.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/vmpressure.h2
-rw-r--r--mm/vmpressure.c10
2 files changed, 6 insertions, 6 deletions
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
index 76be077340e..2081680e015 100644
--- a/include/linux/vmpressure.h
+++ b/include/linux/vmpressure.h
@@ -12,7 +12,7 @@ struct vmpressure {
unsigned long scanned;
unsigned long reclaimed;
/* The lock is used to keep the scanned/reclaimed above in sync. */
- struct mutex sr_lock;
+ struct spinlock sr_lock;
/* The list of vmpressure_event structs. */
struct list_head events;
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 736a6011c2c..f4ee6a190a4 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -180,12 +180,12 @@ static void vmpressure_work_fn(struct work_struct *work)
if (!vmpr->scanned)
return;
- mutex_lock(&vmpr->sr_lock);
+ spin_lock(&vmpr->sr_lock);
scanned = vmpr->scanned;
reclaimed = vmpr->reclaimed;
vmpr->scanned = 0;
vmpr->reclaimed = 0;
- mutex_unlock(&vmpr->sr_lock);
+ spin_unlock(&vmpr->sr_lock);
do {
if (vmpressure_event(vmpr, scanned, reclaimed))
@@ -240,11 +240,11 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
if (!scanned)
return;
- mutex_lock(&vmpr->sr_lock);
+ spin_lock(&vmpr->sr_lock);
vmpr->scanned += scanned;
vmpr->reclaimed += reclaimed;
scanned = vmpr->scanned;
- mutex_unlock(&vmpr->sr_lock);
+ spin_unlock(&vmpr->sr_lock);
if (scanned < vmpressure_win || work_pending(&vmpr->work))
return;
@@ -367,7 +367,7 @@ void vmpressure_unregister_event(struct cgroup *cg, struct cftype *cft,
*/
void vmpressure_init(struct vmpressure *vmpr)
{
- mutex_init(&vmpr->sr_lock);
+ spin_lock_init(&vmpr->sr_lock);
mutex_init(&vmpr->events_lock);
INIT_LIST_HEAD(&vmpr->events);
INIT_WORK(&vmpr->work, vmpressure_work_fn);