From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754864AbcDFL2D (ORCPT ); Wed, 6 Apr 2016 07:28:03 -0400 Received: from outbound-smtp10.blacknight.com ([46.22.139.15]:44251 "EHLO outbound-smtp10.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754082AbcDFLVV (ORCPT ); Wed, 6 Apr 2016 07:21:21 -0400 From: Mel Gorman To: 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: Wed, 6 Apr 2016 12:20:08 +0100 Message-Id: <1459941626-3290-10-git-send-email-mgorman@techsingularity.net> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1459941626-3290-1-git-send-email-mgorman@techsingularity.net> References: <1459941626-3290-1-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 --- mm/vmscan.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 132d9a04de6b..a631972d49e1 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2547,14 +2547,6 @@ static inline bool compaction_ready(struct zone *zone, int order) * 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. * @@ -2569,6 +2561,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc, unsigned long nr_soft_scanned; gfp_t orig_mask; bool reclaimable = false; + pg_data_t *last_pgdat = NULL; /* * If the number of buffer_heads in the machine exceeds the maximum @@ -2581,11 +2574,17 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc, for_each_zone_zonelist_nodemask(zone, z, zonelist, classzone_idx, sc->nodemask) { - if (!populated_zone(zone)) { - sc->reclaim_idx--; - classzone_idx--; + BUG_ON(!populated_zone(zone)); + + /* + * 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 -- 2.6.4