From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754909Ab3KAJBL (ORCPT ); Fri, 1 Nov 2013 05:01:11 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:41164 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752736Ab3KAJBI (ORCPT ); Fri, 1 Nov 2013 05:01:08 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v2.0.1 X-SHieldMailCheckerPolicyVersion: FJ-ISEC-20120718-3 Message-ID: <52736DA4.8000303@jp.fujitsu.com> Date: Fri, 1 Nov 2013 18:00:20 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: KOSAKI Motohiro , Mel Gorman CC: , , , KOSAKI Motohiro Subject: Re: [PATCH] mm: get rid of unnecessary pageblock scanning in setup_zone_migrate_reserve References: <1382562092-15570-1-git-send-email-kosaki.motohiro@gmail.com> <20131030151904.GO2400@suse.de> <527169BB.8020104@gmail.com> <20131031101525.GT2400@suse.de> <52729003.1060209@gmail.com> In-Reply-To: <52729003.1060209@gmail.com> Content-Type: text/plain; charset="ISO-8859-15"; format=flowed Content-Transfer-Encoding: 7bit X-SecurityPolicyCheck-GC: OK by FENCE-Mail Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mel and Kosaki, Thank you for posting patches. I tested your patches. And following table shows time of onlining a memory section. Amount of memory | 128GB | 192GB | 256GB| ------------------------------------------------ linux-3.12-rc7 | 24.3 | 30.2 | 45.6 | Kosaki's first patch | 8.3 | 8.3 | 8.6 | Mel + Kosaki's nit pick | 10.9 | 19.2 | 31.3 | ------------------------------------------------ (millisecond) 128GB : 4 nodes and each node has 32GB of memory 192GB : 6 nodes and each node has 32GB of memory 256GB : 8 nodes and each node has 32GB of memory In my result, Mel's patch does not seem to fix the problem since time is increasing with increasing amount of memory. Thanks, Yasuaki Ishimatsu (2013/11/01 2:14), KOSAKI Motohiro wrote: >>> Nit. I would like to add following hunk. This is just nit because moving >>> reserve pageblock is extreme rare. >>> >>> if (block_migratetype == MIGRATE_RESERVE) { >>> + found++; >>> set_pageblock_migratetype(page, MIGRATE_MOVABLE); >>> move_freepages_block(zone, page, MIGRATE_MOVABLE); >>> } >> >> I don't really see the advantage but if you think it is necessary then I >> do not object either. > > For example, a zone has five pageblock b1,b2,b3,b4,b5 and b1 has MIGRATE_RESERVE. > When hotremove b1 and hotadd again, your code need to scan all of blocks. But > mine only need to scan b1 and b2. I mean that's a hotplug specific optimization. > >