Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964799Ab2KNJP3 (ORCPT ); Wed, 14 Nov 2012 04:15:29 -0500 Received: from mail-pb0-f46.google.com ([209.85.160.46]:38870 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932792Ab2KNJPY (ORCPT ); Wed, 14 Nov 2012 04:15:24 -0500 Date: Wed, 14 Nov 2012 01:15:22 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrew Morton cc: KAMEZAWA Hiroyuki , KOSAKI Motohiro , Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch 2/4] mm, oom: cleanup pagefault oom handler In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2865 Lines: 88 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. Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michal Hocko Signed-off-by: David Rientjes --- mm/oom_kill.c | 49 +++++++------------------------------------------ 1 files changed, 7 insertions(+), 42 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c --- 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); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/