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From: Peter Zijlstra <peterz@infradead.org>
To: David Rientjes <rientjes@google.com>
Cc: Hans Schillstrom <hans@schillstrom.com>,
	Christoph Lameter <cl@gentwo.org>, Ingo Molnar <mingo@redhat.com>,
	Pekka Enberg <penberg@cs.helsinki.fi>,
	Matt Mackall <mpm@selenic.com>,
	Sitsofe Wheeler <sitsofe@yahoo.com>,
	linux-mm@kvack.org
Subject: Re: possible slab deadlock while doing ifenslave
Date: Fri, 14 Oct 2011 01:21:14 +0200	[thread overview]
Message-ID: <1318548074.2374.0.camel@twins> (raw)
In-Reply-To: <alpine.DEB.2.00.1110131557090.10968@chino.kir.corp.google.com>

On Thu, 2011-10-13 at 16:03 -0700, David Rientjes wrote:

> Ok, I think this may be related to what Sitsofe reported in the "lockdep 
> recursive locking detected" thread on LKML (see 
> http://marc.info/?l=linux-kernel&m=131805699106560).
> 
> Peter and Christoph hypothesized that 056c62418cc6 ("slab: fix lockdep 
> warnings") may not have had full coverage when setting lockdep classes for 
> kmem_list3 locks that may be called inside of each other because of 
> off-slab metadata.
> 
> I think it's safe to say there is no deadlock possibility here or we would 
> have seen it since 2006 and this is just a matter of lockdep annotation 
> that needs to be done.  So don't worry too much about the warning even 
> though I know it's annoying and it suppresses future lockdep output (even 
> more annoying!).
> 
> I'm not sure if there's a patch to address that yet, I think one was in 
> the works.  If not, I'll take a look at rewriting that lockdep annotation.

Urgh, I so totally forgot about that.. :-/ So no, no patch yet.

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  reply	other threads:[~2011-10-13 23:21 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-12  8:19 possible slab deadlock while doing ifenslave Hans Schillstrom
2011-10-12 20:35 ` David Rientjes
2011-10-13  8:19   ` Hans Schillstrom
2011-10-13 23:03     ` David Rientjes
2011-10-13 23:21       ` Peter Zijlstra [this message]
2011-10-14  6:30       ` Hans Schillstrom
2011-11-28 21:19       ` Peter Zijlstra
2011-11-28 21:20         ` Peter Zijlstra
2011-11-29 14:58           ` Christoph Lameter
2011-11-29 15:38             ` Peter Zijlstra
2011-11-29 14:55         ` Christoph Lameter

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