From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx186.postini.com [74.125.245.186]) by kanga.kvack.org (Postfix) with SMTP id E0B288D0033 for ; Fri, 11 May 2012 14:17:45 -0400 (EDT) Date: Fri, 11 May 2012 13:17:41 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH v2 04/29] slub: always get the cache from its page in kfree In-Reply-To: <4FAD566C.3000804@parallels.com> Message-ID: References: <1336758272-24284-1-git-send-email-glommer@parallels.com> <1336758272-24284-5-git-send-email-glommer@parallels.com> <4FAD531D.6030007@parallels.com> <4FAD566C.3000804@parallels.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, kamezawa.hiroyu@jp.fujitsu.com, Tejun Heo , Li Zefan , Greg Thelen , Suleiman Souhlal , Michal Hocko , Johannes Weiner , devel@openvz.org, Pekka Enberg On Fri, 11 May 2012, Glauber Costa wrote: > On 05/11/2012 03:06 PM, Christoph Lameter wrote: > > On Fri, 11 May 2012, Glauber Costa wrote: > > > > > > Adding a VM_BUG_ON may be useful to make sure that kmem_cache_free is > > > > always passed the correct slab cache. > > > > > > Well, problem is , it isn't always passed the "correct" slab cache. > > > At least not after this series, since we'll have child caches associated > > > with > > > the main cache. > > > > > > So we'll pass, for instance, kmem_cache_free(dentry_cache...), but will in > > > fact free from the memcg copy of the dentry cache. > > > > Urg. But then please only do this for the MEMCG case and add a fat big > > warning in kmem_cache_free. > > I can do that, of course. > Another option if you don't oppose, is to add another field in the kmem_cache > structure (I tried to keep them at a minimum), > to record the parent cache we got created from. > > Then, it gets trivial to do the following: > > VM_BUG_ON(page->slab != s && page->slab != s->parent_cache); Sounds ok but I need to catch up on what this whole memcg thing in slab allocators should accomplish in order to say something definite. -- 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