Date: Wed, 29 Feb 2012 09:24:30 -0600 (CST)
From: Christoph Lameter <cl@gentwo.org>
To: Namhyung Kim <namhyung.kim@lge.com>
cc: Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>,
        Namhyung Kim <namhyung@gmail.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH -next] slub: set PG_slab on all of slab pages
In-Reply-To: <1330505674-31610-1-git-send-email-namhyung.kim@lge.com>
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On Wed, 29 Feb 2012, Namhyung Kim wrote:

> Unlike SLAB, SLUB doesn't set PG_slab on tail pages, so if a user would
> call free_pages() incorrectly on a object in a tail page, she will get
> confused with the undefined result. Setting the flag would help her by
> emitting a warning on bad_page() in such a case.

NAK

You cannot free a tail page of a compound higher order page independently.
You must free the whole compound.

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