diff mbox series

[07/10] rcu: Make rcu_blocking_is_gp() stop early-boot might_sleep()

Message ID 20230105002305.1768591-7-paulmck@kernel.org (mailing list archive)
State New, archived
Headers show
Series Miscellaneous fixes for v6.3 | expand

Commit Message

Paul E. McKenney Jan. 5, 2023, 12:23 a.m. UTC 
From: Zqiang <qiang1.zhang@intel.com>

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: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/tree.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 0147e69ea85a9..15f9765064727 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -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;
 }