From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx197.postini.com [74.125.245.197]) by kanga.kvack.org (Postfix) with SMTP id B51FC6B0044 for ; Tue, 24 Apr 2012 16:21:47 -0400 (EDT) Received: by yhr47 with SMTP id 47so1016353yhr.14 for ; Tue, 24 Apr 2012 13:21:46 -0700 (PDT) Date: Tue, 24 Apr 2012 13:21:43 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH 17/23] kmem controller charge/uncharge infrastructure In-Reply-To: <20120424142232.GC8626@somewhere> Message-ID: References: <1334959051-18203-1-git-send-email-glommer@parallels.com> <1335138820-26590-6-git-send-email-glommer@parallels.com> <20120424142232.GC8626@somewhere> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Frederic Weisbecker Cc: Glauber Costa , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, devel@openvz.org, KAMEZAWA Hiroyuki , Michal Hocko , Johannes Weiner , Greg Thelen , Suleiman Souhlal , Christoph Lameter , Pekka Enberg On Tue, 24 Apr 2012, Frederic Weisbecker wrote: > > This seems horribly inconsistent with memcg charging of user memory since > > it charges to p->mm->owner and you're charging to p. So a thread attached > > to a memcg can charge user memory to one memcg while charging slab to > > another memcg? > > Charging to the thread rather than the process seem to me the right behaviour: > you can have two threads of a same process attached to different cgroups. > > Perhaps it is the user memory memcg that needs to be fixed? > No, because memory is represented by mm_struct, not task_struct, so you must charge to p->mm->owner to allow for moving threads amongst memcgs later for memory.move_charge_at_immigrate. You shouldn't be able to charge two different memcgs for memory represented by a single mm. > > > + > > > + if (!mem_cgroup_kmem_enabled(memcg)) > > > + goto out; > > > + > > > + mem_cgroup_get(memcg); > > > + ret = memcg_charge_kmem(memcg, gfp, size) == 0; > > > + if (ret) > > > + mem_cgroup_put(memcg); > > > +out: > > > + rcu_read_unlock(); > > > + return ret; > > > +} > > > +EXPORT_SYMBOL(__mem_cgroup_charge_kmem); > > > + > > > +void __mem_cgroup_uncharge_kmem(size_t size) > > > +{ > > > + struct mem_cgroup *memcg; > > > + > > > + rcu_read_lock(); > > > + memcg = mem_cgroup_from_task(current); > > > + > > > + if (!mem_cgroup_kmem_enabled(memcg)) > > > + goto out; > > > + > > > + mem_cgroup_put(memcg); > > > + memcg_uncharge_kmem(memcg, size); > > > +out: > > > + rcu_read_unlock(); > > > +} > > > +EXPORT_SYMBOL(__mem_cgroup_uncharge_kmem); -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org