From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id 64B9C6B0005 for ; Tue, 26 Feb 2013 15:54:23 -0500 (EST) From: ebiederm@xmission.com (Eric W. Biederman) References: <20130213031056.GA32135@marvin.atrad.com.au> <20130213042552.GC32135@marvin.atrad.com.au> <511BADEA.3070403@linux.vnet.ibm.com> <20130226063916.GM16712@marvin.atrad.com.au> <512CD435.30704@linux.vnet.ibm.com> Date: Tue, 26 Feb 2013 12:54:08 -0800 In-Reply-To: <512CD435.30704@linux.vnet.ibm.com> (Dave Hansen's message of "Tue, 26 Feb 2013 07:26:45 -0800") Message-ID: <87d2vmkd8v.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: OOM triggered with plenty of memory free Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Jonathan Woithe , David Rientjes , linux-mm@kvack.org Dave Hansen writes: > On 02/25/2013 10:39 PM, Jonathan Woithe wrote: >> On Wed, Feb 13, 2013 at 07:14:50AM -0800, Dave Hansen wrote: >>> David's analysis looks spot-on. The only other thing I'll add is that >>> it just looks weird that all three kmalloc() caches are so _even_: >>> >>>>> kmalloc-128 1234556 1235168 128 32 1 : tunables 0 0 0 : slabdata 38599 38599 0 >>>>> kmalloc-64 1238117 1238144 64 64 1 : tunables 0 0 0 : slabdata 19346 19346 0 >>>>> kmalloc-32 1236600 1236608 32 128 1 : tunables 0 0 0 : slabdata 9661 9661 0 >>> >>> It's almost like something goes and does 3 allocations in series and >>> leaks them all. > ... >> Given these observations it seems that 2.6.35.11 was leaking memory, >> probably as a result of a bug in the fork() execution path. At this stage >> kmemleak is not showing the same recurring problem under 3.7.9. > > Your kmemleak data shows that the leaks are always from either 'struct > cred', or 'struct pid'. Those are _generally_ tied to tasks, but you > only have a couple thousand task_structs. > > My suspicion would be that something is allocating those structures, but > a refcount got leaked somewhere. 2.6.35.11 is about the same era that > this code went in: > > http://lists.linux-foundation.org/pipermail/containers/2010-June/024720.html > > and it deals with both creds and 'struct pid'. Eric, do you recall any > bugs like this that got fixed along the way? > > I do think it's fairly safe to assume that 3.7.9 doesn't have this > bug. I remember that at one point there was a very subtle leak of I think struct pid. That leak was not associated with the socket code but something else. Eric -- 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