[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <alpine.DEB.2.10.1402181019550.28591@nuc>
Date: Tue, 18 Feb 2014 10:21:10 -0600 (CST)
From: Christoph Lameter <cl@...ux.com>
To: Joonsoo Kim <iamjoonsoo.kim@....com>
cc: Pekka Enberg <penberg@...nel.org>,
Andrew Morton <akpm@...ux-foundation.org>,
David Rientjes <rientjes@...gle.com>,
Wanpeng Li <liwanp@...ux.vnet.ibm.com>, linux-mm@...ck.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 9/9] slab: remove a useless lockdep annotation
On Mon, 17 Feb 2014, Joonsoo Kim wrote:
> > Why change the BAD_ALIEN_MAGIC?
>
> Hello, Christoph.
>
> BAD_ALIEN_MAGIC is only checked by slab_set_lock_classes(). We remove this
> function in this patch, so returning BAD_ALIEN_MAGIC is useless.
Its not useless. The point is if there is a pointer deref then we will see
this as a pointer value and know that it is realted to alien cache
processing.
> And, in fact, BAD_ALIEN_MAGIC is already useless, because alloc_alien_cache()
> can't be called on !CONFIG_NUMA. This function is called if use_alien_caches
> is positive, but on !CONFIG_NUMA, use_alien_caches is always 0. So we don't
> have any chance to meet this BAD_ALIEN_MAGIC in runtime.
Maybe it no longer serves a point. But note that caches may not be
populated because processors/nodes are not up yet.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists