[PATCH 4.9 032/130] rcu: Remove cond_resched() from Tiny synchronize_sched()

From: Greg Kroah-Hartman
Date: Tue Jan 24 2017 - 02:59:47 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

commit f466ae66fa6a599f9a53b5f9bafea4b8cfffa7fb upstream.

It is now legal to invoke synchronize_sched() at early boot, which causes
Tiny RCU's synchronize_sched() to emit spurious splats. This commit
therefore removes the cond_resched() from Tiny RCU's synchronize_sched().

Fixes: 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue")
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
kernel/rcu/tiny.c | 4 ----
1 file changed, 4 deletions(-)

--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -185,9 +185,6 @@ static __latent_entropy void rcu_process
* benefits of doing might_sleep() to reduce latency.)
*
* Cool, huh? (Due to Josh Triplett.)
- *
- * But we want to make this a static inline later. The cond_resched()
- * currently makes this problematic.
*/
void synchronize_sched(void)
{
@@ -195,7 +192,6 @@ void synchronize_sched(void)
lock_is_held(&rcu_lock_map) ||
lock_is_held(&rcu_sched_lock_map),
"Illegal synchronize_sched() in RCU read-side critical section");
- cond_resched();
}
EXPORT_SYMBOL_GPL(synchronize_sched);