On Fri, 19 Oct 2012, Glauber Costa wrote:

struct page already have this information. If we start chaining
caches, this information will always be more trustworthy than
whatever is passed into the function

Yes it does but the information is not standardized between the allocators
yet. Coul you unify that? Come out with a struct page overlay that is as
much the same as possible. Then kfree can also be unified because the
lookup is always the same. That way you can move kfree into slab_common
and avoid modifying multiple allocators.