From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752290Ab2IUNvY (ORCPT ); Fri, 21 Sep 2012 09:51:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33644 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751203Ab2IUNvX (ORCPT ); Fri, 21 Sep 2012 09:51:23 -0400 Message-ID: <505C70C8.5010406@redhat.com> Date: Fri, 21 Sep 2012 09:51:04 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120827 Thunderbird/15.0 MIME-Version: 1.0 To: Mel Gorman CC: Andrew Morton , Richard Davies , Shaohua Li , Avi Kivity , QEMU-devel , KVM , Linux-MM , LKML Subject: Re: [PATCH 0/9] Reduce compaction scanning and lock contention 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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