[v2,2/2] rcu/kvfree: Switch to expedited version in slow path

Commit Message

Uladzislau Rezki Sept. 4, 2024, 2:39 p.m. UTC

For a single argument and its slow path, switch to expedited
version of synchronize_rcu(). This version is considered to
be more faster, thus under a high memory pressure a slow path
becoms more efficient.

Note, latency-sensitive workloads should use rcutree.gp_normal=1,
which will make that synchronize_rcu_expedited() act like a regular
synchronize_rcu(), so no harm done to them.

Signed-off-by: Uladzislau Rezki (Sony) <[e-mail]>
---
 kernel/rcu/tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 182772494cb0..87a64fcffa7f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3856,7 +3856,7 @@  void kvfree_call_rcu(struct rcu_head *head, void *ptr)
 	 */
 	if (!success) {
 		debug_rcu_head_unqueue((struct rcu_head *) ptr);
-		cond_synchronize_rcu_full(&old_snap);
+		cond_synchronize_rcu_expedited_full(&old_snap);
 		kvfree(ptr);
 	}
 }