From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f182.google.com (mail-lb0-f182.google.com [209.85.217.182]) by kanga.kvack.org (Postfix) with ESMTP id 8A2E06B0031 for ; Thu, 19 Dec 2013 04:01:36 -0500 (EST) Received: by mail-lb0-f182.google.com with SMTP id l4so329054lbv.27 for ; Thu, 19 Dec 2013 01:01:35 -0800 (PST) Received: from relay.parallels.com (relay.parallels.com. [195.214.232.42]) by mx.google.com with ESMTPS id le8si1302846lab.33.2013.12.19.01.01.35 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 19 Dec 2013 01:01:35 -0800 (PST) Message-ID: <52B2B5E8.6020307@parallels.com> Date: Thu, 19 Dec 2013 13:01:28 +0400 From: Vladimir Davydov MIME-Version: 1.0 Subject: Re: [PATCH 2/6] memcg, slab: kmem_cache_create_memcg(): free memcg params on error 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> In-Reply-To: <20131219084845.GB9331@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko 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 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() ? Thanks. -- 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