Commit d22959aa authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Clarify fill-the-gap comment in rcu_segcblist_advance() 



Reported-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Reported-by: default avatarNeeraj Upadhyay <quic_neeraju@quicinc.com>
Reported-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent cfe43f47

kernel/rcu/rcu_segcblist.c

+4 −4
Original line number Diff line number Diff line
@@ -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])