From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id B62096B0047 for ; Mon, 14 Dec 2009 18:52:07 -0500 (EST) Received: by gxk24 with SMTP id 24so2216022gxk.6 for ; Mon, 14 Dec 2009 15:52:06 -0800 (PST) Date: Tue, 15 Dec 2009 08:46:36 +0900 From: Minchan Kim Subject: Re: [PATCH 5/8] Use io_schedule() instead schedule() Message-Id: <20091215084636.c7790658.minchan.kim@barrios-desktop> In-Reply-To: <20091214213026.BBBD.A69D9226@jp.fujitsu.com> References: <20091211164651.036f5340@annuminas.surriel.com> <20091214210823.BBAE.A69D9226@jp.fujitsu.com> <20091214213026.BBBD.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: Rik van Riel , lwoodman@redhat.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, minchan.kim@gmail.com List-ID: On Mon, 14 Dec 2009 21:30:54 +0900 (JST) KOSAKI Motohiro wrote: > All task sleeping point in vmscan (e.g. congestion_wait) use > io_schedule. then shrink_zone_begin use it too. > > Signed-off-by: KOSAKI Motohiro > --- > mm/vmscan.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 3562a2d..0880668 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1624,7 +1624,7 @@ static int shrink_zone_begin(struct zone *zone, struct scan_control *sc) > max_zone_concurrent_reclaimers) > break; > > - schedule(); > + io_schedule(); Hmm. We have many cond_resched which is not io_schedule in vmscan.c. In addition, if system doesn't have swap device space and out of page cache due to heavy memory pressue, VM might scan & drop pages until priority is zero or zone is unreclaimable. I think it would be not a IO wait. > > /* > * If other processes freed enough memory while we waited, > -- > 1.6.5.2 > > > -- Kind 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