[PATCH] rcu: add rcu_sync torture type to rcutorture

Use the newly-generic synchronous deferred free function to implement torture
testing for RCU using synchronize_rcu rather than the asynchronous call_rcu.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index 2180ef9..6714b53 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -53,9 +53,10 @@
 		a kernel that disables the scheduling-clock interrupt to
 		idle CPUs.  Boolean parameter, "1" to test, "0" otherwise.
 
-torture_type	The type of RCU to test: "rcu" for the rcu_read_lock()
-		API, "rcu_bh" for the rcu_read_lock_bh() API, and "srcu"
-		for the "srcu_read_lock()" API.
+torture_type	The type of RCU to test: "rcu" for the rcu_read_lock() API,
+		"rcu_sync" for rcu_read_lock() with synchronous reclamation,
+		"rcu_bh" for the rcu_read_lock_bh() API, and "srcu" for the
+		"srcu_read_lock()" API.
 
 verbose		Enable debug printk()s.  Default is disabled.