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Date: Wed, 21 Mar 2007 08:30:27 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: "Pekka Enberg" <penberg@cs.helsinki.fi>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>, "Jarek Poplawski" <jarkao2@o2.pl>,
       "Eric Dumazet" <dada1@cosmosbay.com>, mpm@selenic.com,
       "Christoph Lameter" <clameter@sgi.com>, "ast@domdv.de" <ast@domdv.de>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] slab: deal with NULL pointers passed to kmem_cache_free
Message-Id: <20070321083027.437361f1.akpm@linux-foundation.org>
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On Wed, 21 Mar 2007 16:41:19 +0200 "Pekka Enberg" <penberg@cs.helsinki.fi> wrote:

> On 3/21/07, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > IMHO one way to find them is to actually slow down kmem_cache_free() and see
> > where the performance is hurt.
> 
> Yeah, I'll try to sneak a patch past Andrew.

That would be sneaky.

Thing is, such a patch would amount to adding a test-for-NULL to codepaths
which we *know* do not need it.  There is no point in doing that.