From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752537AbcBCKka (ORCPT ); Wed, 3 Feb 2016 05:40:30 -0500 Received: from mail-pf0-f174.google.com ([209.85.192.174]:36735 "EHLO mail-pf0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750741AbcBCKkZ (ORCPT ); Wed, 3 Feb 2016 05:40:25 -0500 Date: Wed, 3 Feb 2016 19:41:36 +0900 From: Sergey Senozhatsky To: Andrew Morton Cc: Johannes Weiner , Vladimir Davydov , Michal Hocko , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: Re: [PATCH] mm/workingset: do not forget to unlock page Message-ID: <20160203104136.GA517@swordfish> References: <1454493513-19316-1-git-send-email-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1454493513-19316-1-git-send-email-sergey.senozhatsky@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (02/03/16 18:58), Sergey Senozhatsky wrote: > > Do not leave page locked (and RCU read side locked) when > return from workingset_activation() due to disabled memcg > or page not being a page_memcg(). d'oh... sorry, the commit message is simply insane. apparently the patch fixes a new code mm-workingset-per-cgroup-cache-thrash-detection.patch added to -mm tree mm-simplify-lock_page_memcg.patch added to -mm tree so if there is an option to fold this patch into mm-simplify-lock_page_memcg, for example, as a -fix, then I wouldn't mind at all. a better commit message ===8<====8<==== >>From 1d6315221f2f81c53c99f9980158f8ae49dbd582 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Wed, 3 Feb 2016 18:49:16 +0900 Subject: [PATCH] mm/workingset: do not forget to unlock_page in workingset_activation Do not return from workingset_activation() with locked rcu and page. Signed-off-by: Sergey Senozhatsky --- mm/workingset.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/workingset.c b/mm/workingset.c index 14522ed..54138a9 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -315,8 +315,10 @@ void workingset_activation(struct page *page) * XXX: See workingset_refault() - this should return * root_mem_cgroup even for !CONFIG_MEMCG. */ - if (!mem_cgroup_disabled() && !page_memcg(page)) + if (!mem_cgroup_disabled() && !page_memcg(page)) { + unlock_page_memcg(page); return; + } lruvec = mem_cgroup_zone_lruvec(page_zone(page), page_memcg(page)); atomic_long_inc(&lruvec->inactive_age); unlock_page_memcg(page); -- 2.7.0