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From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Subject: Re: [patch 1/7] slab: introduce kzfree()
Cc: kosaki.motohiro@jp.fujitsu.com, David Vrabel <david.vrabel@csr.com>,
       Johannes Weiner <hannes@cmpxchg.org>,
       Andrew Morton <akpm@linux-foundation.org>,
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       linux-kernel@vger.kernel.org, Matt Mackall <mpm@selenic.com>,
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       Nick Piggin <npiggin@suse.de>
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Date: Thu, 19 Feb 2009 10:22:24 +0900 (JST)
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> On Wed, 2009-02-18 at 10:50 +0000, David Vrabel wrote:
> > Johannes Weiner wrote:
> > > +void kzfree(const void *p)
> > 
> > Shouldn't this be void * since it writes to the memory?
> 
> No. kfree() writes to the memory as well to update freelists, poisoning
> and such so kzfree() is not at all different from it.

I don't think so. It's debetable thing.

poisonig is transparent feature from caller.
but the caller of kzfree() know to fill memory and it should know.