Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754857Ab3JaROq (ORCPT ); Thu, 31 Oct 2013 13:14:46 -0400 Received: from mail-yh0-f50.google.com ([209.85.213.50]:41177 "EHLO mail-yh0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752132Ab3JaROp (ORCPT ); Thu, 31 Oct 2013 13:14:45 -0400 Message-ID: <52729003.1060209@gmail.com> Date: Thu, 31 Oct 2013 13:14:43 -0400 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Mel Gorman CC: kosaki.motohiro@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, KOSAKI Motohiro , Yasuaki Ishimatsu 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> In-Reply-To: <20131031101525.GT2400@suse.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 912 Lines: 22 >> 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/