From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752532Ab0AHFah (ORCPT ); Fri, 8 Jan 2010 00:30:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751802Ab0AHFaf (ORCPT ); Fri, 8 Jan 2010 00:30:35 -0500 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:44771 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750800Ab0AHFaf (ORCPT ); Fri, 8 Jan 2010 00:30:35 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Minchan Kim Subject: Re: [PATCH -mmotm-2010-01-06-14-34] check high watermark after shrink zone Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , Mel Gorman , Rik van Riel , linux-mm , lkml In-Reply-To: <20100108141235.ef56b567.minchan.kim@barrios-desktop> References: <20100108141235.ef56b567.minchan.kim@barrios-desktop> Message-Id: <20100108141654.C13E.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Fri, 8 Jan 2010 14:30:30 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Kswapd check that zone have enough free by zone_water_mark. > If any zone doesn't have enough page, it set all_zones_ok to zero. > all_zone_ok makes kswapd retry not sleeping. > > I think the watermark check before shrink zone is pointless. > Kswapd try to shrink zone then the check is meaningul. probably s/meaningul/meaningful/ ? Reviewed-by: KOSAKI Motohiro > > This patch move the check after shrink zone. > Signed-off-by: Minchan Kim > CC: KOSAKI Motohiro > CC: Mel Gorman > CC: Rik van Riel > --- > mm/vmscan.c | 21 +++++++++++---------- > 1 files changed, 11 insertions(+), 10 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 885207a..b81adf8 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2057,9 +2057,6 @@ loop_again: > priority != DEF_PRIORITY) > continue; > > - if (!zone_watermark_ok(zone, order, > - high_wmark_pages(zone), end_zone, 0)) > - all_zones_ok = 0; > temp_priority[i] = priority; > sc.nr_scanned = 0; > note_zone_scanning_priority(zone, priority); > @@ -2099,13 +2096,17 @@ loop_again: > total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2) > sc.may_writepage = 1; > > - /* > - * We are still under min water mark. it mean we have > - * GFP_ATOMIC allocation failure risk. Hurry up! > - */ > - if (!zone_watermark_ok(zone, order, min_wmark_pages(zone), > - end_zone, 0)) > - has_under_min_watermark_zone = 1; > + if (!zone_watermark_ok(zone, order, > + high_wmark_pages(zone), end_zone, 0)) { > + all_zones_ok = 0; > + /* > + * We are still under min water mark. it mean we have > + * GFP_ATOMIC allocation failure risk. Hurry up! > + */ > + if (!zone_watermark_ok(zone, order, min_wmark_pages(zone), > + end_zone, 0)) > + has_under_min_watermark_zone = 1; > + } >