Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU changes from Paul E. McKenney:

- Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar.

- Replace calls of RCU-bh and RCU-sched update-side functions
  to their vanilla RCU counterparts.  This series is a step
  towards complete removal of the RCU-bh and RCU-sched update-side
  functions.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- Documentation updates, including a number of flavor-consolidation
  updates from Joel Fernandes.

- Miscellaneous fixes.

- Automate generation of the initrd filesystem used for
  rcutorture testing.

- Convert spin_is_locked() assertions to instead use lockdep.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- SRCU updates, especially including a fix from Dennis Krein
  for a bag-on-head-class bug.

- RCU torture-test updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index f203b94f6b5b..1971869c4072 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -335,8 +335,7 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
 	/* Initialize and register callbacks for each crcu_array element. */
 	for (i = 0; i < n; i++) {
 		if (checktiny &&
-		    (crcu_array[i] == call_rcu ||
-		     crcu_array[i] == call_rcu_bh)) {
+		    (crcu_array[i] == call_rcu)) {
 			might_sleep();
 			continue;
 		}
@@ -352,8 +351,7 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
 	/* Wait for all callbacks to be invoked. */
 	for (i = 0; i < n; i++) {
 		if (checktiny &&
-		    (crcu_array[i] == call_rcu ||
-		     crcu_array[i] == call_rcu_bh))
+		    (crcu_array[i] == call_rcu))
 			continue;
 		for (j = 0; j < i; j++)
 			if (crcu_array[j] == crcu_array[i])
@@ -822,7 +820,8 @@ static int __init rcu_spawn_tasks_kthread(void)
 	struct task_struct *t;
 
 	t = kthread_run(rcu_tasks_kthread, NULL, "rcu_tasks_kthread");
-	BUG_ON(IS_ERR(t));
+	if (WARN_ONCE(IS_ERR(t), "%s: Could not start Tasks-RCU grace-period kthread, OOM is now expected behavior\n", __func__))
+		return 0;
 	smp_mb(); /* Ensure others see full kthread. */
 	WRITE_ONCE(rcu_tasks_kthread_ptr, t);
 	return 0;