From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755495Ab2GaEuW (ORCPT ); Tue, 31 Jul 2012 00:50:22 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:48525 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755332Ab2GaEuF (ORCPT ); Tue, 31 Jul 2012 00:50:05 -0400 Message-Id: <20120731044313.162306105@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Tue, 31 Jul 2012 05:43:22 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Minchan Kim , KOSAKI Motohiro , Mel Gorman , Rik van Riel , Johannes Weiner , Andrea Arcangeli Subject: [ 12/73] mm/vmscan.c: consider swap space when deciding whether to continue reclaim In-Reply-To: <20120731044310.013763753@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Minchan Kim commit 86cfd3a45042ab242d47f3935a02811a402beab6 upstream. Stable note: Not tracked in Bugzilla. This patch reduces kswapd CPU usage on swapless systems with high anonymous memory usage. It's pointless to continue reclaiming when we have no swap space and lots of anon pages in the inactive list. Without this patch, it is possible when swap is disabled to continue trying to reclaim when there are only anonymous pages in the system even though that will not make any progress. Signed-off-by: Minchan Kim Cc: KOSAKI Motohiro Acked-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Johannes Weiner Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- mm/vmscan.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 974162c..b935e6f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2000,8 +2000,9 @@ static inline bool should_continue_reclaim(struct zone *zone, * inactive lists are large enough, continue reclaiming */ pages_for_compaction = (2UL << sc->order); - inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON) + - zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE); + inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE); + if (nr_swap_pages > 0) + inactive_lru_pages += zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON); if (sc->nr_reclaimed < pages_for_compaction && inactive_lru_pages > pages_for_compaction) return true;