From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) by kanga.kvack.org (Postfix) with ESMTP id EE50B6B0289 for ; Tue, 12 Apr 2016 06:45:35 -0400 (EDT) Received: by mail-wm0-f43.google.com with SMTP id f198so181880182wme.0 for ; Tue, 12 Apr 2016 03:45:35 -0700 (PDT) Received: from outbound-smtp10.blacknight.com (outbound-smtp10.blacknight.com. [46.22.139.15]) by mx.google.com with ESMTPS id u62si23174693wme.91.2016.04.12.03.45.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 12 Apr 2016 03:45:35 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail06.blacknight.ie [81.17.255.152]) by outbound-smtp10.blacknight.com (Postfix) with ESMTPS id B4F6F1C2236 for ; Tue, 12 Apr 2016 11:45:34 +0100 (IST) From: Mel Gorman Subject: [PATCH 22/28] mm, vmscan: Only wakeup kswapd once per node for the requested classzone Date: Tue, 12 Apr 2016 11:44:58 +0100 Message-Id: <1460457904-754-9-git-send-email-mgorman@techsingularity.net> In-Reply-To: <1460457904-754-1-git-send-email-mgorman@techsingularity.net> References: <1460456783-30996-1-git-send-email-mgorman@techsingularity.net> <1460457904-754-1-git-send-email-mgorman@techsingularity.net> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Linux-MM Cc: Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML , Mel Gorman kswapd is woken when zones are below the low watermark but the wakeup decision is not taking the classzone into account. Now that reclaim is node-based, it is only required to wake kswapd once per node and only if all zones are unbalanced for the requested classzone. Note that one node might be checked multiple times but there is no cheap way of tracking what nodes have already been visited for zoneslists that be ordered by either zone or node. Signed-off-by: Mel Gorman --- mm/vmscan.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 9f2376ad4ce3..1931e98d2f67 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3423,6 +3423,7 @@ static int kswapd(void *p) void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx) { pg_data_t *pgdat; + int z; if (!populated_zone(zone)) return; @@ -3436,8 +3437,16 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx) pgdat->kswapd_order = max(pgdat->kswapd_order, order); if (!waitqueue_active(&pgdat->kswapd_wait)) return; - if (zone_balanced(zone, order, 0)) - return; + + /* Only wake kswapd if all zones are unbalanced */ + for (z = 0; z <= classzone_idx; z++) { + zone = pgdat->node_zones + z; + if (!populated_zone(zone)) + continue; + + if (zone_balanced(zone, order, classzone_idx)) + return; + } trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order); wake_up_interruptible(&pgdat->kswapd_wait); -- 2.6.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org