Tracked this down on an Ultra Enterprise 3000. It's a 6-way machine. Odd
thing about this machine (and it's good for finding bugs like this) is that
the CPU id's are not 0 based. For instance, on my machine the CPU's are
6/7/10/11/14/15.
This caused some NULL pointer dereference in kernel/workqueue.c because for
single_threaded workqueue's, it hardcoded the cpu to 0.
I changed the 0's to any_online_cpu(cpu_online_mask), which cpumask.h
claims is "First cpu in mask". So this fits the same usage.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
bce61dd49d