Commit db935dbd authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Linus Torvalds
Browse files

[PATCH] sched: add debugging 



These conditions should now be impossible, and we need to fix them if they
happen.

Signed-off-by: default avatarNick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 39507451

kernel/sched.c

+4 −10
Original line number Diff line number Diff line
@@ -1942,15 +1942,7 @@ static int load_balance(int this_cpu, runqueue_t *this_rq, 
		goto out_balanced;

	}



	/*

	 * This should be "impossible", but since load

	 * balancing is inherently racy and statistical,

	 * it could happen in theory.

	 */

	if (unlikely(busiest == this_rq)) {

		WARN_ON(1);

		goto out_balanced;

	}

	BUG_ON(busiest == this_rq);



	schedstat_add(sd, lb_imbalance[idle], imbalance);
@@ -2052,11 +2044,13 @@ static int load_balance_newidle(int this_cpu, runqueue_t *this_rq, 
	}



	busiest = find_busiest_queue(group);

	if (!busiest || busiest == this_rq) {

	if (!busiest) {

		schedstat_inc(sd, lb_nobusyq[NEWLY_IDLE]);

		goto out_balanced;

	}



	BUG_ON(busiest == this_rq);



	/* Attempt to move tasks */

	double_lock_balance(this_rq, busiest);