[PATCH] rcutorture: add call_rcu_bh() operations

Add operations for the call_rcu_bh() variant of RCU.  Also add an
rcu_batches_completed_bh() function, which is needed by rcutorture.

Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 48 insertions, 2 deletions

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 20e9710fc21c..c0e1cb95dd4f 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -182,6 +182,15 @@ long rcu_batches_completed(void)
         return rcu_ctrlblk.completed;
 }
 
+/*
+ * Return the number of RCU batches processed thus far.  Useful
+ * for debug and statistics.
+ */
+long rcu_batches_completed_bh(void)
+{
+        return rcu_bh_ctrlblk.completed;
+}
+
 static void rcu_barrier_callback(struct rcu_head *notused)
 {
         if (atomic_dec_and_test(&rcu_barrier_cpu_count))
@@ -619,6 +628,7 @@ module_param(qlowmark, int, 0);
 module_param(rsinterval, int, 0);
 #endif
 EXPORT_SYMBOL_GPL(rcu_batches_completed);
+EXPORT_SYMBOL_GPL(rcu_batches_completed_bh);
 EXPORT_SYMBOL_GPL(call_rcu);
 EXPORT_SYMBOL_GPL(call_rcu_bh);
 EXPORT_SYMBOL_GPL(synchronize_rcu);
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index c96b5edd6ed1..4d1c3d247127 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -66,7 +66,7 @@ MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
 module_param(shuffle_interval, int, 0);
 MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
 module_param(torture_type, charp, 0);
-MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu)");
+MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh)");
 
 #define TORTURE_FLAG "-torture:"
 #define PRINTK_STRING(s) \
@@ -246,8 +246,44 @@ static struct rcu_torture_ops rcu_ops = {
         .name = "rcu"
 };
 
+/*
+ * Definitions for rcu_bh torture testing.
+ */
+
+static int rcu_bh_torture_read_lock(void)
+{
+        rcu_read_lock_bh();
+        return 0;
+}
+
+static void rcu_bh_torture_read_unlock(int idx)
+{
+        rcu_read_unlock_bh();
+}
+
+static int rcu_bh_torture_completed(void)
+{
+        return rcu_batches_completed_bh();
+}
+
+static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
+{
+        call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops rcu_bh_ops = {
+        .init = NULL,
+        .cleanup = NULL,
+        .readlock = rcu_bh_torture_read_lock,
+        .readunlock = rcu_bh_torture_read_unlock,
+        .completed = rcu_bh_torture_completed,
+        .deferredfree = rcu_bh_torture_deferred_free,
+        .stats = NULL,
+        .name = "rcu_bh"
+};
+
 static struct rcu_torture_ops *torture_ops[] =
-        { &rcu_ops, NULL };
+        { &rcu_ops, &rcu_bh_ops, NULL };
 
 /*
  * RCU torture writer kthread.  Repeatedly substitutes a new structure