If rcu_report_unblock_qs_rnp() is invoked on something other than preemptible RCU or if there are still preempted tasks blocking the current grace period, something went badly wrong in the caller. This commit therefore adds WARN_ON_ONCE() to these conditions, but leaving the legitimate reason for early exit (rnp->qsmask != 0) unwarned.
Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/tree.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a5dfb18d9b62..42ac3dd88fc5 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2308,8 +2308,10 @@ static void rcu_report_unblock_qs_rnp(struct rcu_state *rsp, struct rcu_node *rnp_p; raw_lockdep_assert_held_rcu_node(rnp); - if (rcu_state_p == &rcu_sched_state || rsp != rcu_state_p || - rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) { + if (WARN_ON_ONCE(rcu_state_p == &rcu_sched_state) || + WARN_ON_ONCE(rsp != rcu_state_p) || + WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)) || + rnp->qsmask != 0) { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return; /* Still need more quiescent states! */ } -- 2.17.1
