From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbaLSNCS (ORCPT ); Fri, 19 Dec 2014 08:02:18 -0500 Received: from cantor2.suse.de ([195.135.220.15]:59525 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752013AbaLSNCQ (ORCPT ); Fri, 19 Dec 2014 08:02:16 -0500 From: Vlastimil Babka To: Andrew Morton , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Vlastimil Babka , Mel Gorman , Johannes Weiner , Michal Hocko , Vladimir Davydov , Rik van Riel , Subject: [PATCH 2/2] mm, vmscan: wake up all pfmemalloc-throttled processes at once Date: Fri, 19 Dec 2014 14:01:56 +0100 Message-Id: <1418994116-23665-2-git-send-email-vbabka@suse.cz> X-Mailer: git-send-email 2.1.2 In-Reply-To: <1418994116-23665-1-git-send-email-vbabka@suse.cz> References: <1418994116-23665-1-git-send-email-vbabka@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Kswapd in balance_pgdate() currently uses wake_up() on processes waiting in throttle_direct_reclaim(), which only wakes up a single process. This might leave processes waiting for longer than necessary, until the check is reached in the next loop iteration. Processes might also be left waiting if zone was fully balanced in single iteration. Note that the comment in balance_pgdat() also says "Wake them", so waking up a single process does not seem intentional. Thus, replace wake_up() with wake_up_all(). Signed-off-by: Vlastimil Babka Cc: Mel Gorman Cc: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Rik van Riel --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 162c3f8..60b999c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3178,7 +3178,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, */ if (waitqueue_active(&pgdat->pfmemalloc_wait) && pfmemalloc_watermark_ok(pgdat)) - wake_up(&pgdat->pfmemalloc_wait); + wake_up_all(&pgdat->pfmemalloc_wait); /* * Fragmentation may mean that the system cannot be rebalanced -- 2.1.2