From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx193.postini.com [74.125.245.193]) by kanga.kvack.org (Postfix) with SMTP id 7F6CB6B00BD for ; Wed, 3 Apr 2013 04:50:59 -0400 (EDT) Date: Wed, 3 Apr 2013 10:50:56 +0200 From: Michal Hocko Subject: Re: [PATCH -v2] memcg: don't do cleanup manually if mem_cgroup_css_online() fails Message-ID: <20130403085056.GD14384@dhcp22.suse.cz> References: <20130402141646.GQ24345@dhcp22.suse.cz> <515AE948.1000704@parallels.com> <20130402142825.GA32520@dhcp22.suse.cz> <515AEC3A.2030401@parallels.com> <20130402150422.GB32520@dhcp22.suse.cz> <515BA6C9.2000704@huawei.com> <20130403074300.GA14384@dhcp22.suse.cz> <515BDEF2.1080900@huawei.com> <20130403081843.GC14384@dhcp22.suse.cz> <515BEA61.9080100@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <515BEA61.9080100@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Li Zefan Cc: Glauber Costa , Johannes Weiner , KAMEZAWA Hiroyuki , LKML , Cgroups , linux-mm@kvack.org On Wed 03-04-13 16:37:53, Li Zefan wrote: > >>> But memcg_update_cache_sizes calls memcg_kmem_clear_activated on the > >>> error path. > >>> > >> > >> But memcg_kmem_mark_dead() checks the ACCOUNT flag not the ACCOUNTED flag. > >> Am I missing something? > >> > > > > Dang. You are right! Glauber, is there any reason why > > memcg_kmem_mark_dead checks only KMEM_ACCOUNTED_ACTIVE rather than > > KMEM_ACCOUNTED_MASK? > > > > This all is very confusing to say the least. > > > > Anyway, this all means that Li's first patch is correct. I am not sure I > > like it though. I think that the refcount cleanup should be done as > > close to where it has been taken as possible otherwise we will end up in > > this "chase the nasty details" again and again. There are definitely two > > bugs here. The one introduced by e4715f01 and the other one introduced > > even earlier (I haven't checked that history yet). I think we should do > > something like the 2 follow up patches but if you guys think that the smaller > > patch from Li is more appropriate then I will not block it. > > > > Or we can queue my patch for 3.9, and then see if we want to change the > tear down process, and if yes we make the change for 3.10. OK, I thought it would be easier but I always end up with something similar to your patch. So feel free to add my Acked-by and parts of my changelog that fit (namely obvious bug introduced by e4715f01 and documentnation of the clean-up path). I have a split up version in case others like it more - will follow. Thanks! -- Michal Hocko SUSE Labs -- 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