1 files changed, 14 insertions, 6 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9ceb93f848cd..21775eebb8f0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1593,15 +1593,23 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
 }
 
 /*
- * Awaken the grace-period kthread.  Don't do a self-awaken, and don't
- * bother awakening when there is nothing for the grace-period kthread
- * to do (as in several CPUs raced to awaken, and we lost), and finally
- * don't try to awaken a kthread that has not yet been created.  If
- * all those checks are passed, track some debug information and awaken.
+ * Awaken the grace-period kthread.  Don't do a self-awaken (unless in
+ * an interrupt or softirq handler), and don't bother awakening when there
+ * is nothing for the grace-period kthread to do (as in several CPUs raced
+ * to awaken, and we lost), and finally don't try to awaken a kthread that
+ * has not yet been created.  If all those checks are passed, track some
+ * debug information and awaken.
+ *
+ * So why do the self-wakeup when in an interrupt or softirq handler
+ * in the grace-period kthread's context?  Because the kthread might have
+ * been interrupted just as it was going to sleep, and just after the final
+ * pre-sleep check of the awaken condition.  In this case, a wakeup really
+ * is required, and is therefore supplied.
  */
 static void rcu_gp_kthread_wake(void)
 {
-        if (current == rcu_state.gp_kthread ||
+        if ((current == rcu_state.gp_kthread &&
+             !in_interrupt() && !in_serving_softirq()) ||
             !READ_ONCE(rcu_state.gp_flags) ||
             !rcu_state.gp_kthread)
                 return;