dm-crypt: use unbound workqueue for request processing

Use unbound workqueue so that work is automatically ballanced between
available CPUs.

Note: workqueue implementation is somehow buggy, so it still does not yield
full parallelization across multiple CPUs.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 drivers/md/dm-crypt.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux-3.2-fast/drivers/md/dm-crypt.c
===================================================================
--- linux-3.2-fast.orig/drivers/md/dm-crypt.c	2012-01-25 03:48:55.000000000 +0100
+++ linux-3.2-fast/drivers/md/dm-crypt.c	2012-01-25 03:49:03.000000000 +0100
@@ -1651,8 +1651,9 @@ static int crypt_ctr(struct dm_target *t
 	cc->crypt_queue = alloc_workqueue("kcryptd",
 					  WQ_NON_REENTRANT|
 					  WQ_CPU_INTENSIVE|
-					  WQ_MEM_RECLAIM,
-					  1);
+					  WQ_MEM_RECLAIM|
+					  WQ_UNBOUND,
+					  num_online_cpus());
 	if (!cc->crypt_queue) {
 		ti->error = "Couldn't create kcryptd queue";
 		goto bad;