From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id CB7C56B0253 for ; Mon, 18 Jul 2016 07:23:11 -0400 (EDT) Received: by mail-wm0-f70.google.com with SMTP id r190so55998196wmr.0 for ; Mon, 18 Jul 2016 04:23:11 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id 201si14240703wms.49.2016.07.18.04.23.10 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 18 Jul 2016 04:23:10 -0700 (PDT) From: Vlastimil Babka Subject: [PATCH 1/8] mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT mode Date: Mon, 18 Jul 2016 13:22:55 +0200 Message-Id: <20160718112302.27381-2-vbabka@suse.cz> In-Reply-To: <20160718112302.27381-1-vbabka@suse.cz> References: <20160718112302.27381-1-vbabka@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Mel Gorman , Joonsoo Kim , David Rientjes , Rik van Riel , Hugh Dickins , Vlastimil Babka 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 cd93ea24c565..892e397655dc 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1200,7 +1200,7 @@ 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 -- 2.9.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org