It appears that at least some of the rcutorture writer stall messages
coincide with unusually long CPU-online operations, for example, no
fewer than 205 seconds in a recent test. It is of course possible that
the writer stall is not unrelated to this unusually long CPU-hotplug
operation, and so this commit adds the rcutorture writer task's CPU to
the stall message to gain more information about this possible connection.
Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
---
kernel/rcu/rcutorture.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index b48d2107f176..75ac749ced7c 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1319,11 +1319,12 @@ rcu_torture_stats_print(void)
srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
&flags, &gpnum, &completed);
wtp = READ_ONCE(writer_task);
- pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state
%#lx\n",
+ pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state
%#lx cpu %d\n",
rcu_torture_writer_state_getname(),
rcu_torture_writer_state,
gpnum, completed, flags,
- wtp == NULL ? ~0UL : wtp->state);
+ wtp == NULL ? ~0UL : wtp->state,
+ wtp == NULL ? -1 : (int)task_cpu(wtp));
show_rcu_gp_kthreads();
rcu_ftrace_dump(DUMP_ALL);
}
--
2.5.2
