[PATCH] knfsd: provide sunrpc pool_mode module option

Provide a module param "pool_mode" for sunrpc.ko which allows a sysadmin to
choose the mode for mapping NFS thread service pools to CPUs.  Values are:

auto	    choose a mapping mode heuristically
global	    (default, same as the pre-2.6.19 code) a single global pool
percpu	    one pool per CPU
pernode	    one pool per NUMA node

Note that since 2.6.19 the hardcoded behaviour has been "auto", this patch
makes the default "global".

The pool mode can be changed after boot/modprobe using /sys, if the NFS and
lockd services have been shut down.  A useful side effect of this change is to
fix a small memory leak when unloading the module.

Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>