Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751951AbaKDCfz (ORCPT ); Mon, 3 Nov 2014 21:35:55 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:47586 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751163AbaKDCft (ORCPT ); Mon, 3 Nov 2014 21:35:49 -0500 X-Original-SENDERIP: 10.177.222.213 X-Original-MAILFROM: iamjoonsoo.kim@lge.com From: Joonsoo Kim To: Andrew Morton Cc: Vlastimil Babka , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim , Michal Nazarewicz , Naoya Horiguchi , Christoph Lameter , Rik van Riel , Mel Gorman , Zhang Yanfei , Joonsoo Kim Subject: [PATCH v2 for v3.18] mm/compaction: skip the range until proper target pageblock is met Date: Tue, 4 Nov 2014 11:37:29 +0900 Message-Id: <1415068649-18040-1-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit 7d49d8868336 ("mm, compaction: reduce zone checking frequency in the migration scanner") makes side-effect that change iteration range calculation. Before change, block_end_pfn is calculated using start_pfn, but, now, blindly add pageblock_nr_pages to previous value. This cause the problem that isolation_start_pfn is larger than block_end_pfn when we isolate the page with more than pageblock order. In this case, isolation would be failed due to invalid range parameter. To prevent this, this patch recalculate the range to find valid target pageblock. Without this patch, CMA with more than pageblock order always fail, but, with this patch, it will succeed. Changes from v1: recalculate the range rather than just skipping to find valid one. add code comment. Signed-off-by: Joonsoo Kim --- mm/compaction.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/compaction.c b/mm/compaction.c index ec74cf0..4f0151c 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -479,6 +479,16 @@ isolate_freepages_range(struct compact_control *cc, block_end_pfn = min(block_end_pfn, end_pfn); + /* + * pfn could pass the block_end_pfn if isolated freepage + * is more than pageblock order. In this case, we adjust + * scanning range to right one. + */ + if (pfn >= block_end_pfn) { + block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); + block_end_pfn = min(block_end_pfn, end_pfn); + } + if (!pageblock_pfn_to_page(pfn, block_end_pfn, cc->zone)) break; -- 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/