rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment

The "pipe_count > RCU_TORTURE_PIPE_LEN" check has a comment saying "Should
not happen, but...".  This is only true when testing an RCU whose grace
periods are always long enough.  This commit therefore fixes this comment.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Closes: https://lore.kernel.org/lkml/CAHk-=wi7rJ-eGq+xaxVfzFEgbL9tdf6Kc8Z89rCpfcQOKm74Tw@mail.gmail.com/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 6b821a7037b03636c853b09695374349002db888..0cb5452ecd945d11780ebee2ae437190ee12c601 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -2000,7 +2000,8 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
        preempt_disable();
        pipe_count = READ_ONCE(p->rtort_pipe_count);
        if (pipe_count > RCU_TORTURE_PIPE_LEN) {
-               /* Should not happen, but... */
+               // Should not happen in a correct RCU implementation,
+               // happens quite often for torture_type=busted.
                pipe_count = RCU_TORTURE_PIPE_LEN;
        }
        completed = cur_ops->get_gp_seq();