From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754685Ab1G2Nbr (ORCPT ); Fri, 29 Jul 2011 09:31:47 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:42732 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753056Ab1G2Nbq (ORCPT ); Fri, 29 Jul 2011 09:31:46 -0400 X-Authority-Analysis: v=1.1 cv=YhhhcVvq/Bf3xBNEvzTEV9JHGW2mXul7kEbaqsyQnMQ= c=1 sm=0 a=U1bfttRP1WkA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=pGLkceISAAAA:8 a=ufHFDILaAAAA:8 a=omOdbC7AAAAA:8 a=meVymXHHAAAA:8 a=Dgdb2dsZrN-3O5mmCdsA:9 a=B9aZ9RYxEGQFHp5ocRsA:7 a=PUjeQqilurYA:10 a=MSl-tDqOz04A:10 a=l7ZknGph1ugA:10 a=jeBq3FmKZ4MA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Subject: Re: [PATCH v3 RESEND] cgroup/kmemcheck: Annotate alloc_page() for cgroup allocations From: Steven Rostedt To: LKML Cc: containers@lists.linux-foundation.org, Johannes Weiner , KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , Minchan Kim , Andrew Morton , Dave Hansen , Catalin Marinas , Randy Dunlap , Michal Hocko , Paul Menage , LiZefan In-Reply-To: <1311732644.21143.5.camel@gandalf.stny.rr.com> References: <1311699911.3526.87.camel@gandalf.stny.rr.com> <20110726173816.GA26597@tiehlicka.suse.cz> <1311702110.3526.98.camel@gandalf.stny.rr.com> <1311702244.3526.100.camel@gandalf.stny.rr.com> <1311704249.3526.106.camel@gandalf.stny.rr.com> <20110726184342.GB26597@tiehlicka.suse.cz> <1311707088.21143.0.camel@gandalf.stny.rr.com> <1311732644.21143.5.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset="ISO-8859-15" Date: Fri, 29 Jul 2011 09:31:41 -0400 Message-ID: <1311946302.21143.37.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.32.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew, On Tue, 2011-07-26 at 22:10 -0400, Steven Rostedt wrote: > [ Resending with CGROUP maintainers Cc'd this time ] Paul sent me a note saying that these patches usually go through -mm, want to take them? Thanks, -- Steve > > When the cgroup base was allocated with kmalloc, it was necessary to > annotate the variable with kmemcheck_not_leak(). But because it has > recently been changed to be allocated with alloc_page() (which skips > kmemleak checks) causes a warning on boot up. > > I was triggering this output: > > allocated 8388608 bytes of page_cgroup > please try 'cgroup_disable=memory' option if you don't want memory cgroups > kmemleak: Trying to color unknown object at 0xf5840000 as Grey > Pid: 0, comm: swapper Not tainted 3.0.0-test #12 > Call Trace: > [] ? printk+0x1d/0x1f^M > [] paint_ptr+0x4f/0x78 > [] kmemleak_not_leak+0x58/0x7d > [] ? __rcu_read_unlock+0x9/0x7d > [] kmemleak_init+0x19d/0x1e9 > [] start_kernel+0x346/0x3ec > [] ? loglevel+0x18/0x18 > [] i386_start_kernel+0xaa/0xb0 > > After a bit of debugging I tracked the object 0xf840000 (and others) > down to the cgroup code. The change from allocating base with kmalloc to > alloc_page() has the base not calling kmemleak_alloc() which adds the > pointer to the object_tree_root, but kmemleak_not_leak() adds it to the > crt_early_log[] table. On kmemleak_init(), the entry is found in the > early_log[] but not the object_tree_root, and this error message is > displayed. > > If alloc_page() fails then it defaults back to vmalloc() which still > uses the kmemleak_alloc() which makes us still need the > kmemleak_not_leak() call. The solution is to call the kmemleak_alloc() > directly if the alloc_page() succeeds. > > Reviewed-by: Michal Hocko > Reviewed-by: Minchan Kim > Acked-by: Johannes Weiner > Acked-by: KAMEZAWA Hiroyuki > Signed-off-by: Steven Rostedt > > diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c > index 53bffc6..1eb534a 100644 > --- a/mm/page_cgroup.c > +++ b/mm/page_cgroup.c > @@ -133,10 +133,13 @@ struct page *lookup_cgroup_page(struct page_cgroup *pc) > static void *__meminit alloc_page_cgroup(size_t size, int nid) > { > void *addr = NULL; > + gfp_t flags = GFP_KERNEL | __GFP_NOWARN; > > - addr = alloc_pages_exact_nid(nid, size, GFP_KERNEL | __GFP_NOWARN); > - if (addr) > + addr = alloc_pages_exact_nid(nid, size, flags); > + if (addr) { > + kmemleak_alloc(addr, size, 1, flags); > return addr; > + } > > if (node_state(nid, N_HIGH_MEMORY)) > addr = vmalloc_node(size, nid); > >