From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id B59A06B005C for ; Wed, 15 Jul 2009 23:21:42 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n6G3Ljnp016584 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Thu, 16 Jul 2009 12:21:45 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 3F8C245DE4E for ; Thu, 16 Jul 2009 12:21:45 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 818C945DE62 for ; Thu, 16 Jul 2009 12:21:44 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 47290E38011 for ; Thu, 16 Jul 2009 12:21:44 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id DB068E3800B for ; Thu, 16 Jul 2009 12:21:43 +0900 (JST) Date: Thu, 16 Jul 2009 12:19:56 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH -mm] throttle direct reclaim when too many pages are isolated already Message-Id: <20090716121956.fc50949f.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090715223854.7548740a@bree.surriel.com> References: <20090715223854.7548740a@bree.surriel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: KOSAKI Motohiro , LKML , linux-mm , Andrew Morton , Wu Fengguang List-ID: On Wed, 15 Jul 2009 22:38:53 -0400 Rik van Riel wrote: > When way too many processes go into direct reclaim, it is possible > for all of the pages to be taken off the LRU. One result of this > is that the next process in the page reclaim code thinks there are > no reclaimable pages left and triggers an out of memory kill. > > One solution to this problem is to never let so many processes into > the page reclaim path that the entire LRU is emptied. Limiting the > system to only having half of each inactive list isolated for > reclaim should be safe. > > Signed-off-by: Rik van Riel > --- > This patch goes on top of Kosaki's "Account the number of isolated pages" > patch series. > > mm/vmscan.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > Index: mmotm/mm/vmscan.c > =================================================================== > --- mmotm.orig/mm/vmscan.c 2009-07-08 21:37:01.000000000 -0400 > +++ mmotm/mm/vmscan.c 2009-07-08 21:39:02.000000000 -0400 > @@ -1035,6 +1035,27 @@ int isolate_lru_page(struct page *page) > } > > /* > + * Are there way too many processes in the direct reclaim path already? > + */ > +static int too_many_isolated(struct zone *zone, int file) > +{ > + unsigned long inactive, isolated; > + > + if (current_is_kswapd()) > + return 0; > + > + if (file) { > + inactive = zone_page_state(zone, NR_INACTIVE_FILE); > + isolated = zone_page_state(zone, NR_ISOLATED_FILE); > + } else { > + inactive = zone_page_state(zone, NR_INACTIVE_ANON); > + isolated = zone_page_state(zone, NR_ISOLATED_ANON); > + } > + > + return isolated > inactive; > +} Why this means "too much" ? And, could you put this check under scanning_global_lru(sc) ? Thanks, -Kame > + > +/* > * shrink_inactive_list() is a helper for shrink_zone(). It returns the number > * of reclaimed pages > */ > @@ -1049,6 +1070,10 @@ static unsigned long shrink_inactive_lis > struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); > int lumpy_reclaim = 0; > > + while (unlikely(too_many_isolated(zone, file))) { > + schedule_timeout_interruptible(HZ/10); > + } > + > /* > * If we need a large contiguous chunk of memory, or have > * trouble getting a small set of contiguous pages, we > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org