Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932690AbbFHN5f (ORCPT ); Mon, 8 Jun 2015 09:57:35 -0400 Received: from cantor2.suse.de ([195.135.220.15]:52432 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752966AbbFHN4x (ORCPT ); Mon, 8 Jun 2015 09:56:53 -0400 From: Mel Gorman To: Linux-MM Cc: Rik van Riel , Johannes Weiner , Michal Hocko , LKML , Mel Gorman Subject: [PATCH 08/25] mm, vmscan: By default have direct reclaim only shrink once per node Date: Mon, 8 Jun 2015 14:56:14 +0100 Message-Id: <1433771791-30567-9-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 2.3.5 In-Reply-To: <1433771791-30567-1-git-send-email-mgorman@suse.de> References: <1433771791-30567-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2380 Lines: 67 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 --- mm/vmscan.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 4d7ddaf4f2f4..50aa650ac206 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2468,14 +2468,6 @@ 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. * @@ -2490,6 +2482,7 @@ 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 @@ -2502,11 +2495,18 @@ 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)) { - 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; + reclaim_idx = zone_idx(zone); /* * Take care memory controller reclaiming has small influence -- 2.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/