From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933066AbcFISGk (ORCPT ); Thu, 9 Jun 2016 14:06:40 -0400 Received: from outbound-smtp02.blacknight.com ([81.17.249.8]:37702 "EHLO outbound-smtp02.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932849AbcFISGh (ORCPT ); Thu, 9 Jun 2016 14:06:37 -0400 From: Mel Gorman To: Andrew Morton , Linux-MM Cc: Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML , Mel Gorman Subject: [PATCH 07/27] mm, vmscan: Remove balance gap Date: Thu, 9 Jun 2016 19:04:23 +0100 Message-Id: <1465495483-11855-8-git-send-email-mgorman@techsingularity.net> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1465495483-11855-1-git-send-email-mgorman@techsingularity.net> References: <1465495483-11855-1-git-send-email-mgorman@techsingularity.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The balance gap was introduced to apply equal pressure to all zones when reclaiming for a higher zone. With node-based LRU, the need for the balance gap is removed and the code is dead so remove it. Signed-off-by: Mel Gorman --- mm/vmscan.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 9368af4cfb06..96bf841f9352 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2488,7 +2488,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc, */ static inline bool compaction_ready(struct zone *zone, int order, int classzone_idx) { - unsigned long balance_gap, watermark; + unsigned long watermark; bool watermark_ok; /* @@ -2497,9 +2497,7 @@ static inline bool compaction_ready(struct zone *zone, int order, int classzone_ * there is a buffer of free pages available to give compaction * a reasonable chance of completing and allocating the page */ - balance_gap = min(low_wmark_pages(zone), DIV_ROUND_UP( - zone->managed_pages, KSWAPD_ZONE_BALANCE_GAP_RATIO)); - watermark = high_wmark_pages(zone) + balance_gap + (2UL << order); + watermark = high_wmark_pages(zone) + (2UL << order); watermark_ok = zone_watermark_ok_safe(zone, 0, watermark, classzone_idx); /* @@ -2962,10 +2960,9 @@ static void age_active_anon(struct pglist_data *pgdat, } while (memcg); } -static bool zone_balanced(struct zone *zone, int order, - unsigned long balance_gap, int classzone_idx) +static bool zone_balanced(struct zone *zone, int order, int classzone_idx) { - unsigned long mark = high_wmark_pages(zone) + balance_gap; + unsigned long mark = high_wmark_pages(zone); return zone_watermark_ok_safe(zone, order, mark, classzone_idx); } @@ -3007,7 +3004,7 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining, if (!populated_zone(zone)) continue; - if (zone_balanced(zone, order, 0, classzone_idx)) + if (zone_balanced(zone, order, classzone_idx)) return true; } @@ -3110,7 +3107,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) break; } - if (!zone_balanced(zone, order, 0, 0)) { + if (!zone_balanced(zone, order, 0)) { classzone_idx = i; break; } else { @@ -3178,7 +3175,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) if (!populated_zone(zone)) continue; - if (zone_balanced(zone, sc.order, 0, classzone_idx)) { + if (zone_balanced(zone, sc.order, classzone_idx)) { clear_bit(PGDAT_CONGESTED, &pgdat->flags); clear_bit(PGDAT_DIRTY, &pgdat->flags); goto out; @@ -3389,7 +3386,7 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx) } if (!waitqueue_active(&pgdat->kswapd_wait)) return; - if (zone_balanced(zone, order, 0, 0)) + if (zone_balanced(zone, order, 0)) return; trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order); -- 2.6.4