[PATCH] Use alloc_percpu to allocate workqueues locally

This patch makes the workqueus use alloc_percpu instead of an array.  The
workqueues are placed on nodes local to each processor.

The workqueue structure can grow to a significant size on a system with
lots of processors if this patch is not applied.  64 bit architectures with
all debugging features enabled and configured for 512 processors will not
be able to boot without this patch.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>