slub: tid must be retrieved from the percpu area of the current processor

As Steven Rostedt has pointer out: rescheduling could occur on a
different processor after the determination of the per cpu pointer and
before the tid is retrieved. This could result in allocation from the
wrong node in slab_alloc().

The effect is much more severe in slab_free() where we could free to the
freelist of the wrong page.

The window for something like that occurring is pretty small but it is
possible.

Change-Id: I9e658e97ed2096f658d6e67739764a86151f13e3
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Git-commit: 7cccd80b4397699902aced1ad3d692d384aaab77
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Merge "slub: tid must be retrieved from the percpu area of the current processor" into android-4.4