From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754613AbcEaNNf (ORCPT ); Tue, 31 May 2016 09:13:35 -0400 Received: from mx2.suse.de ([195.135.220.15]:38094 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752878AbcEaNIg (ORCPT ); Tue, 31 May 2016 09:08:36 -0400 From: Vlastimil Babka To: Michal Hocko , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman , Joonsoo Kim , David Rientjes , Rik van Riel , Hugh Dickins , Vlastimil Babka Subject: [PATCH v2 01/18] mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT mode Date: Tue, 31 May 2016 15:08:01 +0200 Message-Id: <20160531130818.28724-2-vbabka@suse.cz> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160531130818.28724-1-vbabka@suse.cz> References: <20160531130818.28724-1-vbabka@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hugh Dickins At present MIGRATE_SYNC_LIGHT is allowing __isolate_lru_page() to isolate a PageWriteback page, which __unmap_and_move() then rejects with -EBUSY: of course the writeback might complete in between, but that's not what we usually expect, so probably better not to isolate it. When tested by stress-highalloc from mmtests, this has reduced the number of page migrate failures by 60-70%. Signed-off-by: Hugh Dickins Signed-off-by: Vlastimil Babka Acked-by: Michal Hocko --- mm/compaction.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index 1427366ad673..e611f3f90f5f 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1146,7 +1146,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, struct page *page; const isolate_mode_t isolate_mode = (sysctl_compact_unevictable_allowed ? ISOLATE_UNEVICTABLE : 0) | - (cc->mode == MIGRATE_ASYNC ? ISOLATE_ASYNC_MIGRATE : 0); + (cc->mode != MIGRATE_SYNC ? ISOLATE_ASYNC_MIGRATE : 0); /* * Start at where we last stopped, or beginning of the zone as -- 2.8.3