From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760111AbZENHxX (ORCPT ); Thu, 14 May 2009 03:53:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755279AbZENHxO (ORCPT ); Thu, 14 May 2009 03:53:14 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:41392 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756810AbZENHxN (ORCPT ); Thu, 14 May 2009 03:53:13 -0400 From: KOSAKI Motohiro To: Minchan Kim Subject: Re: [PATCH] Prevent shrinking of active anon lru list in case of no swap space Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , LKML , linux-mm , Johannes Weiner , Rik van Riel In-Reply-To: <20090514164010.25335493.minchan.kim@barrios-desktop> References: <20090514155504.9B66.A69D9226@jp.fujitsu.com> <20090514164010.25335493.minchan.kim@barrios-desktop> Message-Id: <20090514164951.9B72.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: Thu, 14 May 2009 16:53:12 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Thu, 14 May 2009 16:19:52 +0900 (JST) > KOSAKI Motohiro wrote: > > > > > > > Now shrink_active_list is called several places. > > > But if we don't have a swap space, we can't reclaim anon pages. > > > So, we don't need deactivating anon pages in anon lru list. > > > > > > Signed-off-by: Minchan Kim > > > Cc: KOSAKI Motohiro > > > Cc: Johannes Weiner > > > Cc: Rik van Riel > > > > hm, The analysis seems right. but > > > > In general branch should put into non frequency path. > > why caller modification as following patch is wrong? > > Yes. You're right. Firstly I though that. > But there are a few place where inactve_anon_is_low is called. > In addition to it, we always have to call with (nr_swap_pages <= 0) with it. > So alone inactive_anon_is_low is lost function's meaning. > > I think it's meaningless. > But We can improve one function wrapper. > > /* I can't be remind proper function name. Can you suggest me ? */ > if (do_we_have_to_shrink_list(zone, &sc)) > > > int do_we_have_to_shrink_list(...) > { > if (inactive_anon_is_low(zone, &sc) && (nr_swap_pages <= 0)) > > } > > What do you think ? The idea except function-name is good. hmm.. sorry. I have no alternative idea. > > > > > /* > > * Do some background aging of the anon list, to give > > * pages a chance to be referenced before reclaiming. > > */ > > - if (inactive_anon_is_low(zone, &sc)) > > + if (inactive_anon_is_low(zone, &sc) && (nr_swap_pages <= 0)) > > shrink_active_list(SWAP_CLUSTER_MAX, zone, > > &sc, priority, 0); > > > > > > > > > > > --- > > > mm/vmscan.c | 6 ++++++ > > > 1 files changed, 6 insertions(+), 0 deletions(-) > > > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > > index 2f9d555..e4d71f4 100644 > > > --- a/mm/vmscan.c > > > +++ b/mm/vmscan.c > > > @@ -1238,6 +1238,12 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, > > > enum lru_list lru; > > > struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); > > > > > > + /* > > > + * we can't shrink anon list in case of no swap space. > > > + */ > > > + if (file == 0 && nr_swap_pages <= 0) > > > + return; > > > + > > > > > > lru_add_drain(); > > > spin_lock_irq(&zone->lru_lock); > > > pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order, > > > -- > > > 1.5.4.3 > > > > > > > > > -- > > > Kinds Regards > > > Minchan Kim > > > > > > > > > -- > Kinds Regards > Minchan Kim > > -- > 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