Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932903AbbFHN71 (ORCPT ); Mon, 8 Jun 2015 09:59:27 -0400 Received: from cantor2.suse.de ([195.135.220.15]:52411 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752910AbbFHN5N (ORCPT ); Mon, 8 Jun 2015 09:57:13 -0400 From: Mel Gorman To: Linux-MM Cc: Rik van Riel , Johannes Weiner , Michal Hocko , LKML , Mel Gorman Subject: [PATCH 18/25] mm, vmscan: Only wakeup kswapd once per node for the requested classzone Date: Mon, 8 Jun 2015 14:56:24 +0100 Message-Id: <1433771791-30567-19-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: 1708 Lines: 51 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 | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index e1fbd89ab750..69916bb9acba 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3381,6 +3381,7 @@ static int kswapd(void *p) void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx) { pg_data_t *pgdat; + int z; bool dummy; if (!populated_zone(zone)) @@ -3395,8 +3396,14 @@ 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, &dummy)) - return; + + /* Only wake kswapd if all zones are unbalanced */ + for (z = 0; z <= zone_idx(zone); z++) { + zone = pgdat->node_zones + z; + + if (zone_balanced(zone, order, 0, classzone_idx, &dummy)) + return; + } trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order); wake_up_interruptible(&pgdat->kswapd_wait); -- 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/