Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752129AbaBNGyO (ORCPT ); Fri, 14 Feb 2014 01:54:14 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:44298 "EHLO LGEAMRELO02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751760AbaBNGyJ (ORCPT ); Fri, 14 Feb 2014 01:54:09 -0500 X-AuditID: 9c93017e-b7cf9ae000004b4b-02-52fdbd8c227f From: Joonsoo Kim To: Andrew Morton Cc: Mel Gorman , Vlastimil Babka , Joonsoo Kim , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim Subject: [PATCH v2 4/5] mm/compaction: check pageblock suitability once per pageblock Date: Fri, 14 Feb 2014 15:54:02 +0900 Message-Id: <1392360843-22261-5-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1392360843-22261-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1392360843-22261-1-git-send-email-iamjoonsoo.kim@lge.com> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org isolation_suitable() and migrate_async_suitable() is used to be sure that this pageblock range is fine to be migragted. It isn't needed to call it on every page. Current code do well if not suitable, but, don't do well when suitable. 1) It re-checks isolation_suitable() on each page of a pageblock that was already estabilished as suitable. 2) It re-checks migrate_async_suitable() on each page of a pageblock that was not entered through the next_pageblock: label, because last_pageblock_nr is not otherwise updated. This patch fixes situation by 1) calling isolation_suitable() only once per pageblock and 2) always updating last_pageblock_nr to the pageblock that was just checked. Additionally, move PageBuddy() check after pageblock unit check, since pageblock check is the first thing we should do and makes things more simple. [vbabka@suse.cz: rephrase commit description] Acked-by: Vlastimil Babka Signed-off-by: Joonsoo Kim diff --git a/mm/compaction.c b/mm/compaction.c index b1ba297..56536d3 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -520,26 +520,31 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, /* If isolation recently failed, do not retry */ pageblock_nr = low_pfn >> pageblock_order; - if (!isolation_suitable(cc, page)) - goto next_pageblock; + if (last_pageblock_nr != pageblock_nr) { + int mt; + + last_pageblock_nr = pageblock_nr; + if (!isolation_suitable(cc, page)) + goto next_pageblock; + + /* + * For async migration, also only scan in MOVABLE + * blocks. Async migration is optimistic to see if + * the minimum amount of work satisfies the allocation + */ + mt = get_pageblock_migratetype(page); + if (!cc->sync && !migrate_async_suitable(mt)) { + cc->finished_update_migrate = true; + skipped_async_unsuitable = true; + goto next_pageblock; + } + } /* Skip if free */ if (PageBuddy(page)) continue; /* - * For async migration, also only scan in MOVABLE blocks. Async - * migration is optimistic to see if the minimum amount of work - * satisfies the allocation - */ - if (!cc->sync && last_pageblock_nr != pageblock_nr && - !migrate_async_suitable(get_pageblock_migratetype(page))) { - cc->finished_update_migrate = true; - skipped_async_unsuitable = true; - goto next_pageblock; - } - - /* * Check may be lockless but that's ok as we recheck later. * It's possible to migrate LRU pages and balloon pages * Skip any other type of page @@ -621,7 +626,6 @@ check_compact_cluster: next_pageblock: low_pfn = ALIGN(low_pfn + 1, pageblock_nr_pages) - 1; - last_pageblock_nr = pageblock_nr; } acct_isolated(zone, locked, cc); -- 1.7.9.5 -- 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/