Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752007Ab3JaEY6 (ORCPT ); Thu, 31 Oct 2013 00:24:58 -0400 Received: from mail-ee0-f53.google.com ([74.125.83.53]:58069 "EHLO mail-ee0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750762Ab3JaEY5 (ORCPT ); Thu, 31 Oct 2013 00:24:57 -0400 From: kosaki.motohiro@gmail.com To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, KOSAKI Motohiro , Mel Gorman Subject: [PATCH] mm: __rmqueue_fallback() should respect pageblock type Date: Thu, 31 Oct 2013 00:24:49 -0400 Message-Id: <1383193489-27331-1-git-send-email-kosaki.motohiro@gmail.com> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1800 Lines: 46 From: KOSAKI Motohiro When __rmqueue_fallback() don't find out a free block with the same size of required, it splits a larger page and puts back rest peiece of the page to free list. But it has one serious mistake. When putting back, __rmqueue_fallback() always use start_migratetype if type is not CMA. However, __rmqueue_fallback() is only called when all of start_migratetype queue are empty. That said, __rmqueue_fallback always put back memory to wrong queue except try_to_steal_freepages() changed pageblock type (i.e. requested size is smaller than half of page block). Finally, antifragmentation framework increase fragmenation instead of decrease. Mel's original anti fragmentation do the right thing. But commit 47118af076 (mm: mmzone: MIGRATE_CMA migration type added) broke it. This patch restores sane and old behavior. Cc: Mel Gorman Signed-off-by: KOSAKI Motohiro --- mm/page_alloc.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dd886fa..ea7bb9a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1101,7 +1101,7 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype) */ expand(zone, page, order, current_order, area, is_migrate_cma(migratetype) - ? migratetype : start_migratetype); + ? migratetype : new_type); trace_mm_page_alloc_extfrag(page, order, current_order, start_migratetype, migratetype, -- 1.7.1 -- 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/