From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:48729) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TF3db-0005WC-Be for qemu-devel@nongnu.org; Fri, 21 Sep 2012 09:51:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TF3dV-0001Hy-Cj for qemu-devel@nongnu.org; Fri, 21 Sep 2012 09:51:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6942) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TF3dV-0001Gc-4G for qemu-devel@nongnu.org; Fri, 21 Sep 2012 09:51:17 -0400 Message-ID: <505C70C8.5010406@redhat.com> Date: Fri, 21 Sep 2012 09:51:04 -0400 From: Rik van Riel MIME-Version: 1.0 References: <1348224383-1499-1-git-send-email-mgorman@suse.de> In-Reply-To: <1348224383-1499-1-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/9] Reduce compaction scanning and lock contention List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mel Gorman Cc: Richard Davies , KVM , QEMU-devel , LKML , Linux-MM , Avi Kivity , Andrew Morton , Shaohua Li On 09/21/2012 06:46 AM, Mel Gorman wrote: > Hi Andrew, > > Richard Davies and Shaohua Li have both reported lock contention > problems in compaction on the zone and LRU locks as well as > significant amounts of time being spent in compaction. This series > aims to reduce lock contention and scanning rates to reduce that CPU > usage. Richard reported at https://lkml.org/lkml/2012/9/21/91 that > this series made a big different to a problem he reported in August > (http://marc.info/?l=kvm&m=134511507015614&w=2). > One way or the other, this series has a large impact on the amount of > scanning compaction does when there is a storm of THP allocations. Andrew, Mel and I have discussed the stuff in this series quite a bit, and I am convinced this is the way forward with compaction. -- All rights reversed