[PATCH 1/2] softlockup: convert read_lock in hung_task to rcu_read_lock

[Mandeep Singh Baines <msb@google.com>]

Peter Zijlstra suggested the use of RCU.

Signed-off-by: Mandeep Singh Baines <msb@google.com>
---
 kernel/hung_task.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index ba8ccd4..a841db3 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -127,7 +127,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout)
 	if (test_taint(TAINT_DIE) || did_panic)
 		return;
 
-	read_lock(&tasklist_lock);
+	rcu_read_lock();
 	do_each_thread(g, t) {
 		if (!--max_count)
 			goto unlock;
@@ -136,7 +136,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout)
 			check_hung_task(t, now, timeout);
 	} while_each_thread(g, t);
  unlock:
-	read_unlock(&tasklist_lock);
+	rcu_read_unlock();
 }
 
 static void update_poll_jiffies(void)
-- 
1.5.4.5