Once removed, an rcu_torture element can be deferred-freed by a chain of call_rcu() invocations, with each callback invoking another round of call_rcu() until either a fixed number of call_rcu() invocations have been chained or until the test ends. This means that if the test ends, some of the rcu_torture elements will be "stranded" partway through the deferred-free process, which results in false-positive warnings from rcu_torture_writer() due to lack of forward progress should the test end just at the end of a stutter interval.
This commit therefore suppresses rcu_torture_writer()'s forward-progress checks when the test ends in order to avoid these false-positive reports.. Reported-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/rcutorture.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index ef6f6dedf4c4..a3f5488a319a 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1014,7 +1014,8 @@ rcu_torture_writer(void *arg) rcu_torture_writer_state = RTWS_STUTTER; if (stutter_wait("rcu_torture_writer") && !READ_ONCE(rcu_fwd_cb_nodelay) && - !cur_ops->slow_gps) + !cur_ops->slow_gps && + !torture_must_stop()) for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) if (list_empty(&rcu_tortures[i].rtort_free) && rcu_access_pointer(rcu_torture_current) != -- 2.17.1
