From faab3ae329a6efb96995aeb72a68a99f664fed38 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 23 Jun 2025 12:39:55 -0700 Subject: rcu: Document that rcu_barrier() hurries lazy callbacks This commit adds to the rcu_barrier() kerneldoc header stating that this function hurries lazy callbacks and that it does not normally result in additional RCU grace periods. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/rcu/tree.c') diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8eff357b0436..1291e0761d70 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3800,6 +3800,11 @@ static void rcu_barrier_handler(void *cpu_in) * to complete. For example, if there are no RCU callbacks queued anywhere * in the system, then rcu_barrier() is within its rights to return * immediately, without waiting for anything, much less an RCU grace period. + * In fact, rcu_barrier() will normally not result in any RCU grace periods + * beyond those that were already destined to be executed. + * + * In kernels built with CONFIG_RCU_LAZY=y, this function also hurries all + * pending lazy RCU callbacks. */ void rcu_barrier(void) { -- cgit v1.2.3