From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx157.postini.com [74.125.245.157]) by kanga.kvack.org (Postfix) with SMTP id B7FC16B004D for ; Tue, 15 May 2012 13:43:54 -0400 (EDT) Message-ID: <4FB295C5.7080008@redhat.com> Date: Tue, 15 May 2012 13:43:33 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 1/2] swap: allow swap readahead to be merged References: <1336996709-8304-1-git-send-email-ehrhardt@linux.vnet.ibm.com> <1336996709-8304-2-git-send-email-ehrhardt@linux.vnet.ibm.com> In-Reply-To: <1336996709-8304-2-git-send-email-ehrhardt@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: ehrhardt@linux.vnet.ibm.com Cc: linux-mm@kvack.org, axboe@kernel.dk On 05/14/2012 07:58 AM, ehrhardt@linux.vnet.ibm.com wrote: > From: Christian Ehrhardt > > Swap readahead works fine, but the I/O to disk is almost always done in page > size requests, despite the fact that readahead submits 1< at a time. > On older kernels the old per device plugging behavior might have captured > this and merged the requests, but currently all comes down to much more I/Os > than required. > > On a single device this might not be an issue, but as soon as a server runs > on shared san resources savin I/Os not only improves swapin throughput but > also provides a lower resource utilization. > Signed-off-by: Christian Ehrhardt Acked-by: Rik van Riel -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org