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Date: Wed, 16 Jan 2013 08:59:43 +0800
From: Liu Bo <bo.li.liu@oracle.com>
To: Christoph Lameter <cl@linux.com>
Cc: linux-mm@kvack.org, linux-btrfs@vger.kernel.org,
        linux-kernel@vger.kernel.org, Zach Brown <zab@zabbo.net>,
        Pekka Enberg <penberg@kernel.org>
Subject: Re: [PATCH] mm/slab: add a leak decoder callback
Message-ID: <20130116005942.GA3942@liubo>
Reply-To: bo.li.liu@oracle.com
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On Tue, Jan 15, 2013 at 04:30:52PM +0000, Christoph Lameter wrote:
> On Mon, 14 Jan 2013, Liu Bo wrote:
> 
> > This adds a leak decoder callback so that kmem_cache_destroy()
> > can use to generate debugging output for the allocated objects.
> 
> Interesting idea.
> 
> > @@ -3787,6 +3789,9 @@ static int slab_unmergeable(struct kmem_cache *s)
> >  	if (s->ctor)
> >  		return 1;
> >
> > +	if (s->decoder)
> > +		return 1;
> > +
> >  	/*
> >  	 * We may have set a slab to be unmergeable during bootstrap.
> >  	 */
> 
> The merge processing occurs during kmem_cache_create and you are setting
> up the decoder field afterwards! Wont work.

You're right, I miss the lock part.

thanks,
liubo