From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 117E86B017B for ; Thu, 14 May 2009 03:39:46 -0400 (EDT) Received: by pxi37 with SMTP id 37so582678pxi.12 for ; Thu, 14 May 2009 00:40:23 -0700 (PDT) Date: Thu, 14 May 2009 16:40:10 +0900 From: Minchan Kim Subject: Re: [PATCH] Prevent shrinking of active anon lru list in case of no swap space Message-Id: <20090514164010.25335493.minchan.kim@barrios-desktop> In-Reply-To: <20090514155504.9B66.A69D9226@jp.fujitsu.com> References: <20090514141025.239cafe5.minchan.kim@barrios-desktop> <20090514155504.9B66.A69D9226@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Minchan Kim , Andrew Morton , LKML , linux-mm , Johannes Weiner , Rik van Riel List-ID: 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 ? > > /* > * 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