From ae74138da609c576b221c765efa8b81b2365f465 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Tue, 16 Oct 2007 23:26:00 -0700 Subject: [PATCH] oom: convert zone_scan_lock from mutex to spinlock There's no reason to sleep in try_set_zone_oom() or clear_zonelist_oom() if the lock can't be acquired; it will be available soon enough once the zonelist scanning is done. All other threads waiting for the OOM killer are also contingent on the exiting task being able to acquire the lock in clear_zonelist_oom() so it doesn't make sense to put it to sleep. Cc: Andrea Arcangeli Cc: Christoph Lameter Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 183a964ca61b..a64decb5b13f 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -28,7 +28,7 @@ int sysctl_panic_on_oom; int sysctl_oom_kill_allocating_task; -static DEFINE_MUTEX(zone_scan_mutex); +static DEFINE_SPINLOCK(zone_scan_mutex); /* #define DEBUG */ /** @@ -396,7 +396,7 @@ int try_set_zone_oom(struct zonelist *zonelist) z = zonelist->zones; - mutex_lock(&zone_scan_mutex); + spin_lock(&zone_scan_mutex); do { if (zone_is_oom_locked(*z)) { ret = 0; @@ -413,7 +413,7 @@ int try_set_zone_oom(struct zonelist *zonelist) zone_set_flag(*z, ZONE_OOM_LOCKED); } while (*(++z) != NULL); out: - mutex_unlock(&zone_scan_mutex); + spin_unlock(&zone_scan_mutex); return ret; } @@ -428,11 +428,11 @@ void clear_zonelist_oom(struct zonelist *zonelist) z = zonelist->zones; - mutex_lock(&zone_scan_mutex); + spin_lock(&zone_scan_mutex); do { zone_clear_flag(*z, ZONE_OOM_LOCKED); } while (*(++z) != NULL); - mutex_unlock(&zone_scan_mutex); + spin_unlock(&zone_scan_mutex); } /** -- 2.20.1