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>
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
index 76be077..2081680 100644
--- a/include/linux/vmpressure.h
+++ b/include/linux/vmpressure.h
@@ -12,7 +12,7 @@
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 736a601..f4ee6a1 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -180,12 +180,12 @@
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 @@
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_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);