From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f52.google.com (mail-wm0-f52.google.com [74.125.82.52]) by kanga.kvack.org (Postfix) with ESMTP id 8EF8B828DF for ; Tue, 23 Feb 2016 10:19:56 -0500 (EST) Received: by mail-wm0-f52.google.com with SMTP id g62so214971107wme.0 for ; Tue, 23 Feb 2016 07:19:56 -0800 (PST) Received: from outbound-smtp12.blacknight.com (outbound-smtp12.blacknight.com. [46.22.139.17]) by mx.google.com with ESMTPS id d3si45309363wja.39.2016.02.23.07.19.55 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Feb 2016 07:19:55 -0800 (PST) Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp12.blacknight.com (Postfix) with ESMTPS id 51E361C195A for ; Tue, 23 Feb 2016 15:19:55 +0000 (GMT) Date: Tue, 23 Feb 2016 15:19:53 +0000 From: Mel Gorman Subject: [PATCH 22/27] mm, vmscan: Only wakeup kswapd once per node for the requested classzone Message-ID: <20160223151953.GH2854@techsingularity.net> References: <1456239890-20737-1-git-send-email-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1456239890-20737-1-git-send-email-mgorman@techsingularity.net> Sender: owner-linux-mm@kvack.org List-ID: To: Linux-MM Cc: Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML 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 9f1492b077be..e92765eb0a1e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3411,6 +3411,7 @@ 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; @@ -3424,8 +3425,16 @@ 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, 0)) - return; + + /* Only wake kswapd if all zones are unbalanced */ + for (z = 0; z <= zone_idx(zone); z++) { + zone = pgdat->node_zones + z; + if (!populated_zone(zone)) + continue; + + if (zone_balanced(zone, order, 0, 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