From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752531AbdIIWyY (ORCPT ); Sat, 9 Sep 2017 18:54:24 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41335 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768AbdIIWYk (ORCPT ); Sat, 9 Sep 2017 18:24:40 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Vladimir Davydov" , "Michal Hocko" , "Yu Zhao" , "Linus Torvalds" Date: Sat, 09 Sep 2017 22:47:39 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 086/106] swap: cond_resched in swap_cgroup_prepare() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.93-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Yu Zhao commit ef70762948dde012146926720b70e79736336764 upstream. I saw need_resched() warnings when swapping on large swapfile (TBs) because continuously allocating many pages in swap_cgroup_prepare() took too long. We already cond_resched when freeing page in swap_cgroup_swapoff(). Do the same for the page allocation. Link: http://lkml.kernel.org/r/20170604200109.17606-1-yuzhao@google.com Signed-off-by: Yu Zhao Acked-by: Michal Hocko Acked-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings --- mm/page_cgroup.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/page_cgroup.c +++ b/mm/page_cgroup.c @@ -399,6 +399,9 @@ static int swap_cgroup_prepare(int type) if (!page) goto not_enough_page; ctrl->map[idx] = page; + + if (!(idx % SWAP_CLUSTER_MAX)) + cond_resched(); } return 0; not_enough_page: