From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id 0ABE36B003D for ; Thu, 11 Jul 2013 11:44:13 -0400 (EDT) Received: by mail-qe0-f52.google.com with SMTP id i11so4523972qej.39 for ; Thu, 11 Jul 2013 08:44:13 -0700 (PDT) Date: Thu, 11 Jul 2013 08:44:08 -0700 From: Tejun Heo Subject: Re: [PATCH v2] vmpressure: make sure memcg stays alive until all users are signaled Message-ID: <20130711154408.GA9229@mtj.dyndns.org> References: <20130710184254.GA16979@mtj.dyndns.org> <20130711083110.GC21667@dhcp22.suse.cz> <51DE701C.6010800@huawei.com> <20130711092542.GD21667@dhcp22.suse.cz> <51DE7AAF.6070004@huawei.com> <20130711093300.GE21667@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130711093300.GE21667@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Li Zefan , Anton Vorontsov , cgroups@vger.kernel.org, linux-mm@kvack.org, Johannes Weiner , KAMEZAWA Hiroyuki , KOSAKI Motohiro Hello, Michal. On Thu, Jul 11, 2013 at 11:33:00AM +0200, Michal Hocko wrote: > +static inline > +struct mem_cgroup *vmpressure_to_mem_cgroup(struct vmpressure *vmpr) > +{ > + return container_of(vmpr, struct mem_cgroup, vmpressure); > +} > + > +void vmpressure_pin_memcg(struct vmpressure *vmpr) > +{ > + struct mem_cgroup *memcg = vmpressure_to_mem_cgroup(vmpr); > + > + css_get(&memcg->css); > +} > + > +void vmpressure_unpin_memcg(struct vmpressure *vmpr) > +{ > + struct mem_cgroup *memcg = vmpressure_to_mem_cgroup(vmpr); > + > + css_put(&memcg->css); > +} So, while this *should* work, can't we just cancel/flush the work item from offline? There doesn't seem to be any possible deadlocks from my shallow glance and those mutexes don't seem to be held for long (do they actually need to be mutexes? what blocks inside them?). Also, while at it, can you please remove the work_pending() check? They're almost always spurious or racy and should be avoided in general. Thanks. -- tejun -- 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