Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753232AbbKXLzj (ORCPT ); Tue, 24 Nov 2015 06:55:39 -0500 Received: from mail-wm0-f42.google.com ([74.125.82.42]:38223 "EHLO mail-wm0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752769AbbKXLzM (ORCPT ); Tue, 24 Nov 2015 06:55:12 -0500 From: Michal Hocko To: Andrew Morton Cc: Johannes Weiner , Vladimir Davydov , Vlastimil Babka , Mel Gorman , , LKML , Michal Hocko Subject: [PATCH 2/2] mm, vmscan: do not overestimate anonymous reclaimable pages Date: Tue, 24 Nov 2015 12:55:00 +0100 Message-Id: <1448366100-11023-3-git-send-email-mhocko@kernel.org> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1448366100-11023-1-git-send-email-mhocko@kernel.org> References: <1448366100-11023-1-git-send-email-mhocko@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1682 Lines: 50 From: Michal Hocko zone_reclaimable_pages considers all anonymous pages on LRUs reclaimable if there is at least one entry on the swap storage left. This can be really misleading when the swap is short on space and skew reclaim decisions based on zone_reclaimable_pages. Fix this by clamping the number to the minimum of the available swap space and anon LRU pages. Signed-off-by: Michal Hocko --- mm/vmscan.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 946d348f5040..646001a1f279 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -195,15 +195,20 @@ static bool sane_reclaim(struct scan_control *sc) static unsigned long zone_reclaimable_pages(struct zone *zone) { unsigned long nr; + long nr_swap = get_nr_swap_pages(); nr = zone_page_state(zone, NR_ACTIVE_FILE) + zone_page_state(zone, NR_INACTIVE_FILE) + zone_page_state(zone, NR_ISOLATED_FILE); - if (get_nr_swap_pages() > 0) - nr += zone_page_state(zone, NR_ACTIVE_ANON) + - zone_page_state(zone, NR_INACTIVE_ANON) + - zone_page_state(zone, NR_ISOLATED_ANON); + if (nr_swap > 0) { + unsigned long anon; + + anon = zone_page_state(zone, NR_ACTIVE_ANON) + + zone_page_state(zone, NR_INACTIVE_ANON) + + zone_page_state(zone, NR_ISOLATED_ANON); + nr += min_t(unsigned long, nr_swap, anon); + } return nr; } -- 2.6.2 -- 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/