From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752354AbbAUJfE (ORCPT ); Wed, 21 Jan 2015 04:35:04 -0500 Received: from smtp.codeaurora.org ([198.145.11.231]:36662 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750813AbbAUJe5 (ORCPT ); Wed, 21 Jan 2015 04:34:57 -0500 From: Vinayak Menon To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, mgorman@suse.de, minchan@kernel.org, vbabka@suse.cz, rientjes@google.com, iamjoonsoo.kim@lge.com, Vinayak Menon Subject: [PATCH] mm: compaction: fix the page state calculation in too_many_isolated Date: Wed, 21 Jan 2015 15:04:24 +0530 Message-Id: <1421832864-30643-1-git-send-email-vinmenon@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit "3611badc1baa" (mm: vmscan: fix the page state calculation in too_many_isolated) fixed an issue where a number of tasks were blocked in reclaim path for seconds, because of vmstat_diff not being synced in time. A similar problem can happen in isolate_migratepages_block, similar calculation is performed. This patch fixes that. Signed-off-by: Vinayak Menon --- mm/compaction.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 546e571..2d9730d 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -537,21 +537,43 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc) mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]); } -/* Similar to reclaim, but different enough that they don't share logic */ -static bool too_many_isolated(struct zone *zone) +static bool __too_many_isolated(struct zone *zone, int safe) { unsigned long active, inactive, isolated; - inactive = zone_page_state(zone, NR_INACTIVE_FILE) + + if (safe) { + inactive = zone_page_state_snapshot(zone, NR_INACTIVE_FILE) + + zone_page_state_snapshot(zone, NR_INACTIVE_ANON); + active = zone_page_state_snapshot(zone, NR_ACTIVE_FILE) + + zone_page_state_snapshot(zone, NR_ACTIVE_ANON); + isolated = zone_page_state_snapshot(zone, NR_ISOLATED_FILE) + + zone_page_state_snapshot(zone, NR_ISOLATED_ANON); + } else { + inactive = zone_page_state(zone, NR_INACTIVE_FILE) + zone_page_state(zone, NR_INACTIVE_ANON); - active = zone_page_state(zone, NR_ACTIVE_FILE) + + active = zone_page_state(zone, NR_ACTIVE_FILE) + zone_page_state(zone, NR_ACTIVE_ANON); - isolated = zone_page_state(zone, NR_ISOLATED_FILE) + + isolated = zone_page_state(zone, NR_ISOLATED_FILE) + zone_page_state(zone, NR_ISOLATED_ANON); + } return isolated > (inactive + active) / 2; } +/* Similar to reclaim, but different enough that they don't share logic */ +static bool too_many_isolated(struct zone *zone) +{ + /* + * __too_many_isolated(safe=0) is fast but inaccurate, because it + * doesn't account for the vm_stat_diff[] counters. So if it looks + * like too_many_isolated() is about to return true, fall back to the + * slower, more accurate zone_page_state_snapshot(). + */ + if (unlikely(__too_many_isolated(zone, 0))) + return __too_many_isolated(zone, 1); + return 0; +} + /** * isolate_migratepages_block() - isolate all migrate-able pages within * a single pageblock -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation