From efacd02e4f57d94e934ba5c84f10f8ce91158770 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 12 Dec 2012 13:52:06 -0800 Subject: [PATCH] mm, oom: cleanup pagefault oom handler To lock the entire system from parallel oom killing, it's possible to pass in a zonelist with all zones rather than using for_each_populated_zone() for the iteration. This obsoletes try_set_system_oom() and clear_system_oom() so that they can be removed. Signed-off-by: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Reviewed-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 49 +++++++------------------------------------------ 1 file changed, 7 insertions(+), 42 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index fe36205a7f8a..0e30ff7b21c5 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -591,43 +591,6 @@ void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask) spin_unlock(&zone_scan_lock); } -/* - * Try to acquire the oom killer lock for all system zones. Returns zero if a - * parallel oom killing is taking place, otherwise locks all zones and returns - * non-zero. - */ -static int try_set_system_oom(void) -{ - struct zone *zone; - int ret = 1; - - spin_lock(&zone_scan_lock); - for_each_populated_zone(zone) - if (zone_is_oom_locked(zone)) { - ret = 0; - goto out; - } - for_each_populated_zone(zone) - zone_set_flag(zone, ZONE_OOM_LOCKED); -out: - spin_unlock(&zone_scan_lock); - return ret; -} - -/* - * Clears ZONE_OOM_LOCKED for all system zones so that failed allocation - * attempts or page faults may now recall the oom killer, if necessary. - */ -static void clear_system_oom(void) -{ - struct zone *zone; - - spin_lock(&zone_scan_lock); - for_each_populated_zone(zone) - zone_clear_flag(zone, ZONE_OOM_LOCKED); - spin_unlock(&zone_scan_lock); -} - /** * out_of_memory - kill the "best" process when we run out of memory * @zonelist: zonelist pointer @@ -708,15 +671,17 @@ out: /* * The pagefault handler calls here because it is out of memory, so kill a - * memory-hogging task. If a populated zone has ZONE_OOM_LOCKED set, a parallel - * oom killing is already in progress so do nothing. If a task is found with - * TIF_MEMDIE set, it has been killed so do nothing and allow it to exit. + * memory-hogging task. If any populated zone has ZONE_OOM_LOCKED set, a + * parallel oom killing is already in progress so do nothing. */ void pagefault_out_of_memory(void) { - if (try_set_system_oom()) { + struct zonelist *zonelist = node_zonelist(first_online_node, + GFP_KERNEL); + + if (try_set_zonelist_oom(zonelist, GFP_KERNEL)) { out_of_memory(NULL, 0, 0, NULL, false); - clear_system_oom(); + clear_zonelist_oom(zonelist, GFP_KERNEL); } schedule_timeout_killable(1); } -- 2.39.2