From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 729C26B004D for ; Thu, 26 Nov 2009 23:36:25 -0500 (EST) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id nAR4aMrd003753 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Fri, 27 Nov 2009 13:36:23 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 7165C45DE51 for ; Fri, 27 Nov 2009 13:36:22 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 4F24545DE4E for ; Fri, 27 Nov 2009 13:36:22 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 281941DB8041 for ; Fri, 27 Nov 2009 13:36:22 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id B9FE81DB8043 for ; Fri, 27 Nov 2009 13:36:21 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH-RFC] cfq: Disable low_latency by default for 2.6.32 In-Reply-To: <20091126121945.GB13095@csn.ul.ie> References: <20091126121945.GB13095@csn.ul.ie> Message-Id: <20091127133511.A7DB.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Fri, 27 Nov 2009 13:36:20 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, Jens Axboe , Andrew Morton , Linus Torvalds , Frans Pop , Jiri Kosina , Sven Geggus , Karol Lewandowski , Tobias Oetiker , Pekka Enberg , Rik van Riel , Christoph Lameter , Stephan von Krawczynski , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: > Signed-off-by: Mel Gorman > --- > block/cfq-iosched.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c > index aa1e953..dc33045 100644 > --- a/block/cfq-iosched.c > +++ b/block/cfq-iosched.c > @@ -2543,7 +2543,7 @@ static void *cfq_init_queue(struct request_queue *q) > cfqd->cfq_slice[1] = cfq_slice_sync; > cfqd->cfq_slice_async_rq = cfq_slice_async_rq; > cfqd->cfq_slice_idle = cfq_slice_idle; > - cfqd->cfq_latency = 1; > + cfqd->cfq_latency = 0; > cfqd->hw_tag = 1; > cfqd->last_end_sync_rq = jiffies; > return cfqd; Great. Probably we can reenable this feature at 2.6.33. but there isn't any reason to take any risk at 2.6.32. i.e. This simple disabling is best. I like this. Reviewed-by: KOSAKI Motohiro -- 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