From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753150AbZLOAfs (ORCPT ); Mon, 14 Dec 2009 19:35:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750907AbZLOAfr (ORCPT ); Mon, 14 Dec 2009 19:35:47 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:50079 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750793AbZLOAfq (ORCPT ); Mon, 14 Dec 2009 19:35:46 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Minchan Kim Subject: Re: [PATCH 6/8] Stop reclaim quickly when the task reclaimed enough lots pages Cc: kosaki.motohiro@jp.fujitsu.com, Rik van Riel , lwoodman@redhat.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: <20091215091107.219644fe.minchan.kim@barrios-desktop> References: <20091214213103.BBC0.A69D9226@jp.fujitsu.com> <20091215091107.219644fe.minchan.kim@barrios-desktop> Message-Id: <20091215092654.CDB3.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: Tue, 15 Dec 2009 09:35:41 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Mon, 14 Dec 2009 21:31:36 +0900 (JST) > KOSAKI Motohiro wrote: > > > > > From latency view, There isn't any reason shrink_zones() continue to > > reclaim another zone's page if the task reclaimed enough lots pages. > > > > Signed-off-by: KOSAKI Motohiro > > --- > > mm/vmscan.c | 16 ++++++++++++---- > > 1 files changed, 12 insertions(+), 4 deletions(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index 0880668..bf229d3 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1654,7 +1654,7 @@ static void shrink_zone_end(struct zone *zone, struct scan_control *sc) > > /* > > * This is a basic per-zone page freer. Used by both kswapd and direct reclaim. > > */ > > -static void shrink_zone(int priority, struct zone *zone, > > +static int shrink_zone(int priority, struct zone *zone, > > struct scan_control *sc) > > { > > unsigned long nr[NR_LRU_LISTS]; > > @@ -1669,7 +1669,7 @@ static void shrink_zone(int priority, struct zone *zone, > > > > ret = shrink_zone_begin(zone, sc); > > if (ret) > > - return; > > + return ret; > > > > /* If we have no swap space, do not bother scanning anon pages. */ > > if (!sc->may_swap || (nr_swap_pages <= 0)) { > > @@ -1692,6 +1692,7 @@ static void shrink_zone(int priority, struct zone *zone, > > &reclaim_stat->nr_saved_scan[l]); > > } > > > > + ret = 0; > > while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] || > > nr[LRU_INACTIVE_FILE]) { > > for_each_evictable_lru(l) { > > @@ -1712,8 +1713,10 @@ static void shrink_zone(int priority, struct zone *zone, > > * with multiple processes reclaiming pages, the total > > * freeing target can get unreasonably large. > > */ > > - if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY) > > + if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY) { > > + ret = -ERESTARTSYS; > > Just nitpick. > > shrink_zone's return value is matter? > shrink_zones never handle that. shrink_zones() stop vmscan quickly if ret isn't !0. if we already scanned rather than nr_to_reclaim, we can stop vmscan. > As a matter of fact, I am worried about this patch. > > My opinion is we put aside this patch until we can solve Larry's problem. > We could apply this patch in future. > > I don't want to see the side effect while we focus Larry's problem. > But If you mind my suggestion, I also will not bother you by this nitpick. > > Thanks for great cleanup and improving VM, Kosaki. :) I agree with Larry's issue is highest priority.