[PATCH] CPU Scheduler: fix potential error in runqueue nr_uninterruptible count

[PATCH] CPU Scheduler: fix potential error in runqueue nr_uninterruptible count

Problem:

In the function try_to_wake_up(), when the runqueue's nr_uninterruptible
field is decremented it's possible (on SMP systems) that the pointer no
longer points to the runqueue that the task being woken was on when it went
to sleep.  This would cause the wrong runqueue's field to be decremented
and the correct one tp remain unchanged.

Fix:

Save a pointer to the old runqueue at the beginning of the function and use
it when decrementing nr_uninterruptible.

Signed-off-by: Peter Williams <pwil3058@bigpond.net.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>