From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx152.postini.com [74.125.245.152]) by kanga.kvack.org (Postfix) with SMTP id 68F8E6B006E for ; Wed, 15 Aug 2012 05:24:10 -0400 (EDT) Date: Wed, 15 Aug 2012 11:24:05 +0200 From: Michal Hocko Subject: Re: [PATCH v2 07/11] mm: Allocate kernel pages to the right memcg Message-ID: <20120815092404.GA23985@dhcp22.suse.cz> References: <1344517279-30646-1-git-send-email-glommer@parallels.com> <1344517279-30646-8-git-send-email-glommer@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1344517279-30646-8-git-send-email-glommer@parallels.com> Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, devel@openvz.org, Johannes Weiner , Andrew Morton , kamezawa.hiroyu@jp.fujitsu.com, Christoph Lameter , David Rientjes , Pekka Enberg , Pekka Enberg , Suleiman Souhlal On Thu 09-08-12 17:01:15, Glauber Costa wrote: [...] > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index b956cec..da341dc 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2532,6 +2532,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, > struct page *page = NULL; > int migratetype = allocflags_to_migratetype(gfp_mask); > unsigned int cpuset_mems_cookie; > + void *handle = NULL; > > gfp_mask &= gfp_allowed_mask; > > @@ -2543,6 +2544,13 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, > return NULL; > > /* > + * Will only have any effect when __GFP_KMEMCG is set. > + * This is verified in the (always inline) callee > + */ > + if (!memcg_kmem_new_page(gfp_mask, &handle, order)) > + return NULL; When the previous patch introduced this function I thought the handle obfuscantion is to prevent from spreading struct mem_cgroup inside the page allocator but memcg_kmem_commit_page uses the type directly. So why that obfuscation? Even handle as a name sounds unnecessarily confusing. I would go with struct mem_cgroup **memcgp or even return the pointer on success or NULL otherwise. [...] > +EXPORT_SYMBOL(__free_accounted_pages); Why exported? Btw. this is called from call_rcu context but it itself calls call_rcu down the chain in mem_cgroup_put. Is it safe? [...] > +EXPORT_SYMBOL(free_accounted_pages); here again -- 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