diff mbox series

[rcu,2/3] srcu: No need to advance/accelerate if no callback enqueued

Message ID 20231212174817.11919-2-neeraj.iitr10@gmail.com
State New
Headers
Series SRCU updates for v6.8 |

Commit Message

Neeraj Upadhyay (AMD) Dec. 12, 2023, 5:48 p.m. UTC 
  From: Frederic Weisbecker <frederic@kernel.org>

While in grace period start, there is nothing to accelerate and
therefore no need to advance the callbacks either if no callback is
to be enqueued.

Spare these needless operations in this case.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
---
 kernel/rcu/srcutree.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index e9356a103626..2bfc8ed1eed2 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -1261,9 +1261,11 @@  static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp,
 	 *     period (gp_num = X + 8). So acceleration fails.
 	 */
 	s = rcu_seq_snap(&ssp->srcu_sup->srcu_gp_seq);
-	rcu_segcblist_advance(&sdp->srcu_cblist,
-			      rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq));
-	WARN_ON_ONCE(!rcu_segcblist_accelerate(&sdp->srcu_cblist, s) && rhp);
+	if (rhp) {
+		rcu_segcblist_advance(&sdp->srcu_cblist,
+				      rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq));
+		WARN_ON_ONCE(!rcu_segcblist_accelerate(&sdp->srcu_cblist, s));
+	}
 	if (ULONG_CMP_LT(sdp->srcu_gp_seq_needed, s)) {
 		sdp->srcu_gp_seq_needed = s;
 		needgp = true;