Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754693Ab3J3UTM (ORCPT ); Wed, 30 Oct 2013 16:19:12 -0400 Received: from mail-yh0-f44.google.com ([209.85.213.44]:47110 "EHLO mail-yh0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752698Ab3J3UTK (ORCPT ); Wed, 30 Oct 2013 16:19:10 -0400 Message-ID: <527169BB.8020104@gmail.com> Date: Wed, 30 Oct 2013 16:19:07 -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> In-Reply-To: <20131030151904.GO2400@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: 1974 Lines: 52 > @@ -3926,11 +3929,11 @@ static void setup_zone_migrate_reserve(struct zone *zone) > /* > * Reserve blocks are generally in place to help high-order atomic > * allocations that are short-lived. A min_free_kbytes value that > - * would result in more than 2 reserve blocks for atomic allocations > - * is assumed to be in place to help anti-fragmentation for the > - * future allocation of hugepages at runtime. > + * would result in more than MAX_MIGRATE_RESERVE_BLOCKS reserve blocks > + * for atomic allocations is assumed to be in place to help > + * anti-fragmentation for the future allocation of hugepages at runtime. > */ > - reserve = min(2, reserve); > + reserve = min(MAX_MIGRATE_RESERVE_BLOCKS, reserve); > > for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { > if (!pfn_valid(pfn)) > @@ -3956,6 +3959,7 @@ static void setup_zone_migrate_reserve(struct zone *zone) > /* If this block is reserved, account for it */ > if (block_migratetype == MIGRATE_RESERVE) { > reserve--; > + found++; > continue; > } > > @@ -3970,6 +3974,10 @@ static void setup_zone_migrate_reserve(struct zone *zone) > } > } > > + /* If all possible reserve blocks have been found, we're done */ > + if (found >= MAX_MIGRATE_RESERVE_BLOCKS) > + break; > + > /* > * If the reserve is met and this is a previous reserved block, > * take it back 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); } -- 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/