Reported-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Reported-by: Neeraj Upadhyay <quic_neeraju@xxxxxxxxxxx>
Reported-by: Boqun Feng <boqun.feng@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/rcu_segcblist.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c
index 81145c3ece25..c54ea2b6a36b 100644
--- a/kernel/rcu/rcu_segcblist.c
+++ b/kernel/rcu/rcu_segcblist.c
@@ -505,10 +505,10 @@ void rcu_segcblist_advance(struct rcu_segcblist *rsclp, unsigned long seq)
WRITE_ONCE(rsclp->tails[j], rsclp->tails[RCU_DONE_TAIL]);
/*
- * Callbacks moved, so clean up the misordered ->tails[] pointers
- * that now point into the middle of the list of ready-to-invoke
- * callbacks. The overall effect is to copy down the later pointers
- * into the gap that was created by the now-ready segments.
+ * Callbacks moved, so there might be an empty RCU_WAIT_TAIL
+ * and a non-empty RCU_NEXT_READY_TAIL. If so, copy the
+ * RCU_NEXT_READY_TAIL segment to fill the RCU_WAIT_TAIL gap
+ * created by the now-ready-to-invoke segments.
*/
for (j = RCU_WAIT_TAIL; i < RCU_NEXT_TAIL; i++, j++) {
if (rsclp->tails[j] == rsclp->tails[RCU_NEXT_TAIL])
--
2.31.1.189.g2e36527f23
