Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758835AbZLNXwR (ORCPT ); Mon, 14 Dec 2009 18:52:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758812AbZLNXwN (ORCPT ); Mon, 14 Dec 2009 18:52:13 -0500 Received: from mail-yw0-f182.google.com ([209.85.211.182]:49425 "EHLO mail-yw0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758818AbZLNXwG (ORCPT ); Mon, 14 Dec 2009 18:52:06 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding; b=KvE6RguMsp9XPw3t7TkVsZA9x7r1Wk96my6P0gNmADfwUtM8u2FQnJuLlwEc2u9auY LdmkHv0Mg6/l402fi0SaMU+warJaiByvNILFLfgL0xnX9W6a0nt6eHyNfI/Siy8FRJ5u ag6lcfHMKpKOllqOuqPtFo0jY+elNJiDjERCw= Date: Tue, 15 Dec 2009 08:46:36 +0900 From: Minchan Kim 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 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> X-Mailer: Sylpheed 2.6.0 (GTK+ 2.16.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1369 Lines: 51 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/