Messages in this thread |  | | Date | Tue, 18 Feb 2014 10:21:10 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [PATCH 9/9] slab: remove a useless lockdep annotation |
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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.
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