[PATCH] rcu/torture: Change order of warning and trace dump

From: Anna-Maria Behnsen
Date: Mon Apr 11 2022 - 11:19:21 EST


Dumping a big ftrace buffer could lead to a RCU stall. So there is the
ftrace buffer and the stall information which needs to be printed. When
there is additionaly a WARN_ON() which describes the reason for the ftrace
buffer dump and the WARN_ON() is executed _after_ ftrace buffer dump, the
information get lost in the middle of the RCU stall information.

Therefore print WARN_ON() message before dumping the ftrace buffer in
rcu_torture_writer().

Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
Reviewed-by: Benedikt Spranger <b.spranger@xxxxxxxxxxxxx>
---
kernel/rcu/rcutorture.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 55d049c39608..cbbe37d7701e 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1287,8 +1287,8 @@ rcu_torture_writer(void *arg)
if (list_empty(&rcu_tortures[i].rtort_free) &&
rcu_access_pointer(rcu_torture_current) !=
&rcu_tortures[i]) {
- rcu_ftrace_dump(DUMP_ALL);
WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
+ rcu_ftrace_dump(DUMP_ALL);
}
if (stutter_waited)
sched_set_normal(current, oldnice);
--
2.20.1