Fix for the "kmem [-s|-S] <address>" command, and the "rd -S[S]"
and "bt -F[F]" options.  Without the patch, if the page structure
associated with a memory address still contains a (stale) pointer to
the address of a kmem_cache structure, but whose page.flags does not
have the PG_slab bit set, the address is incorrectly presumed to be
contained within that slab cache.  As as result, the "kmem" command
may display one or more messages indicating a "bad inuse counter", a
"bad next pointer" or a "bad s_mem pointer", followed by an "address
not found in cache" error message.  The "rd -S[S]" and "bt -F[F]"
commands may mislabel memory locations as belonging to slab caches.
(anderson@redhat.com)