From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f199.google.com (mail-qt0-f199.google.com [209.85.216.199]) by kanga.kvack.org (Postfix) with ESMTP id BAB826B0292 for ; Thu, 31 Aug 2017 08:19:41 -0400 (EDT) Received: by mail-qt0-f199.google.com with SMTP id e2so1329690qta.8 for ; Thu, 31 Aug 2017 05:19:41 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id r76si2878376qkh.369.2017.08.31.05.19.40 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 31 Aug 2017 05:19:40 -0700 (PDT) Date: Thu, 31 Aug 2017 14:19:37 +0200 From: Artem Savkov Subject: Re: possible circular locking dependency mmap_sem/cpu_hotplug_lock.rw_sem Message-ID: <20170831121908.kin3mm25ebszhpvn@shodan.usersys.redhat.com> References: <20170807140947.nhfz2gel6wytl6ia@shodan.usersys.redhat.com> <20170830141543.qhipikpog6mkqe5b@dhcp22.suse.cz> <20170830154315.sa57wasw64rvnuhe@dhcp22.suse.cz> <20170831111006.i7srs56xki4bjx34@shodan.usersys.redhat.com> <20170831120951.hqlu2ai5i7hly7nk@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170831120951.hqlu2ai5i7hly7nk@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Thomas Gleixner , "Paul E. McKenney" , LKML , Johannes Weiner , linux-mm@kvack.org On Thu, Aug 31, 2017 at 02:09:51PM +0200, Michal Hocko wrote: > On Thu 31-08-17 13:10:06, Artem Savkov wrote: > > Hi Michal, > > > > On Wed, Aug 30, 2017 at 05:43:15PM +0200, Michal Hocko wrote: > > > The previous patch is insufficient. drain_all_stock can still race with > > > the memory offline callback and the underlying memcg disappear. So we > > > need to be more careful and pin the css on the memcg. This patch > > > instead... > > > > Tried this on top of rc7 and it does fix the splat for me. > > Thanks for testing! Can I assume your Tested-by? Didn't test much more than the case that was causing it, but yes. Reported-and-tested-by: Artem Savkov -- Regards, Artem -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org