From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752406AbcFUOR5 (ORCPT ); Tue, 21 Jun 2016 10:17:57 -0400 Received: from outbound-smtp03.blacknight.com ([81.17.249.16]:49554 "EHLO outbound-smtp03.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752096AbcFUOR4 (ORCPT ); Tue, 21 Jun 2016 10:17:56 -0400 From: Mel Gorman To: Andrew Morton , Linux-MM Cc: Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML , Mel Gorman Subject: [PATCH 09/27] mm, vmscan: By default have direct reclaim only shrink once per node Date: Tue, 21 Jun 2016 15:15:48 +0100 Message-Id: <1466518566-30034-10-git-send-email-mgorman@techsingularity.net> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1466518566-30034-1-git-send-email-mgorman@techsingularity.net> References: <1466518566-30034-1-git-send-email-mgorman@techsingularity.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Direct reclaim iterates over all zones in the zonelist and shrinking them but this is in conflict with node-based reclaim. In the default case, only shrink once per node. Signed-off-by: Mel Gorman Acked-by: Johannes Weiner Acked-by: Vlastimil Babka --- mm/vmscan.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index ce712ca1f696..2dafaa06884b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2546,14 +2546,6 @@ static inline bool compaction_ready(struct zone *zone, int order, int classzone_ * try to reclaim pages from zones which will satisfy the caller's allocation * request. * - * We reclaim from a zone even if that zone is over high_wmark_pages(zone). - * Because: - * a) The caller may be trying to free *extra* pages to satisfy a higher-order - * allocation or - * b) The target zone may be at high_wmark_pages(zone) but the lower zones - * must go *over* high_wmark_pages(zone) to satisfy the `incremental min' - * zone defense algorithm. - * * If a zone is deemed to be full of pinned pages then just give it a light * scan then give up on it. */ @@ -2565,6 +2557,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc, unsigned long nr_soft_reclaimed; unsigned long nr_soft_scanned; gfp_t orig_mask; + pg_data_t *last_pgdat = NULL; /* * If the number of buffer_heads in the machine exceeds the maximum @@ -2589,10 +2582,19 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc, while (!populated_zone(zone->zone_pgdat->node_zones + classzone_idx)) { classzone_idx--; - continue; } /* + * Shrink each node in the zonelist once. If the zonelist is + * ordered by zone (not the default) then a node may be + * shrunk multiple times but in that case the user prefers + * lower zones being preserved + */ + if (zone->zone_pgdat == last_pgdat) + continue; + last_pgdat = zone->zone_pgdat; + + /* * Take care memory controller reclaiming has small influence * to global LRU. */ -- 2.6.4