Commit 3d1adf7a authored by Zqiang's avatar Zqiang Committed by Paul E. McKenney
Browse files

rcu: Make rcu_blocking_is_gp() stop early-boot might_sleep() 



Currently, rcu_blocking_is_gp() invokes might_sleep() even during early
boot when interrupts are disabled and before the scheduler is scheduling.
This is at best an accident waiting to happen.  Therefore, this commit
moves that might_sleep() under an rcu_scheduler_active check in order
to ensure that might_sleep() is not invoked unless sleeping might actually
happen.

Signed-off-by: default avatarZqiang <qiang1.zhang@intel.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 2d7f00b2

kernel/rcu/tree.c

+3 −2
Original line number Diff line number Diff line
@@ -3333,9 +3333,10 @@ void __init kfree_rcu_scheduler_running(void) 
 */

static int rcu_blocking_is_gp(void)

{

	if (rcu_scheduler_active != RCU_SCHEDULER_INACTIVE)

	if (rcu_scheduler_active != RCU_SCHEDULER_INACTIVE) {

		might_sleep();

		return false;

	might_sleep();  /* Check for RCU read-side critical section. */

	}

	return true;

}