From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ea0-f171.google.com (mail-ea0-f171.google.com [209.85.215.171]) by kanga.kvack.org (Postfix) with ESMTP id 6F29E6B003A for ; Thu, 19 Dec 2013 04:19:05 -0500 (EST) Received: by mail-ea0-f171.google.com with SMTP id h10so324809eak.16 for ; Thu, 19 Dec 2013 01:19:04 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l44si3469074eem.40.2013.12.19.01.19.04 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 19 Dec 2013 01:19:04 -0800 (PST) Date: Thu, 19 Dec 2013 10:19:03 +0100 From: Michal Hocko Subject: Re: [PATCH 2/6] memcg, slab: kmem_cache_create_memcg(): free memcg params on error Message-ID: <20131219091903.GF9331@dhcp22.suse.cz> References: <6f02b2d079ffd0990ae335339c803337b13ecd8c.1387372122.git.vdavydov@parallels.com> <9420ad797a2cfa14c23ad1ba6db615a2a51ffee0.1387372122.git.vdavydov@parallels.com> <20131218170649.GC31080@dhcp22.suse.cz> <52B292FD.8040603@parallels.com> <20131219084845.GB9331@dhcp22.suse.cz> <52B2B5E8.6020307@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52B2B5E8.6020307@parallels.com> Sender: owner-linux-mm@kvack.org List-ID: To: Vladimir Davydov Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, devel@openvz.org, Johannes Weiner , Glauber Costa , Christoph Lameter , Pekka Enberg , Andrew Morton On Thu 19-12-13 13:01:28, Vladimir Davydov wrote: > On 12/19/2013 12:48 PM, Michal Hocko wrote: > > On Thu 19-12-13 10:32:29, Vladimir Davydov wrote: > >> On 12/18/2013 09:06 PM, Michal Hocko wrote: > >>> On Wed 18-12-13 17:16:53, Vladimir Davydov wrote: > >>>> Plus, rename memcg_register_cache() to memcg_init_cache_params(), > >>>> because it actually does not register the cache anywhere, but simply > >>>> initialize kmem_cache::memcg_params. > >>> I've almost missed this is a memory leak fix. > >> Yeah, the comment is poor, sorry about that. Will fix it. > >> > >>> I do not mind renaming and the name but wouldn't > >>> memcg_alloc_cache_params suit better? > >> As you wish. I don't have a strong preference for memcg_init_cache_params. > > I really hate naming... but it seems that alloc is a better fit. _init_ > > would expect an already allocated object. > > > > Btw. memcg_free_cache_params is called only once which sounds > > suspicious. The regular destroy path should use it as well? > > [...] > > The usual destroy path uses memcg_release_cache(), which does the trick. > Plus, it actually "unregisters" the cache. BTW, I forgot to substitute > kfree(s->memcg_params) with the new memcg_free_cache_params() there. > Although it currently does not break anything, better to fix it in case > new memcg_free_cache_params() will have to do something else. > > And you're right about the naming is not good. > > Currently we have: > > on create: > memcg_register_cache() > memcg_cache_list_add() > on destroy: > memcg_release_cache() > > After this patch we would have: > > on create: > memcg_alloc_cache_params() > memcg_register_cache() > on destroy: > memcg_release_cache() > > Still not perfect: "alloc" does not have corresponding "free", while > "register" does not have corresponding "unregister", everything is done > by "release". > > What do you think about splitting memcg_release_cache() into two functions: > > memcg_unregister_cache() > memcg_free_cache_params() yes I am all for cleaning up this mess. I am still trying to wrap my head around what is each of this function responsible for. Absolute lack of documentation is not helping at all... > > ? > > 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