Messages in this thread | | | Date | Tue, 11 Apr 2017 14:32:08 -0700 | From | "Paul E. McKenney" <> | Subject | Re: There is a Tasks RCU stall warning |
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On Tue, Apr 11, 2017 at 05:21:07PM -0400, Steven Rostedt wrote: > On Tue, 11 Apr 2017 14:18:02 -0700 > "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote: > > > Hello, Steve, > > > > Network connectivity issues... :-/ > > ug > > > There is already a Tasks RCU stall warning, but it waits for > > ten -minutes- before complaining. You can change this with the > > rcupdate.rcu_task_stall_timeout kernel boot parameter, if you wish. > > > > Or did you wait longer than ten minutes? > > Hmm, I may have waited longer. But I can try again and shorten the > timeout.
Failing that, you might try carefully placed printk() calls in rcu_tasks_kthread(). The loop spinning on non-empty rcu_tasks_holdouts() should loop at most once per second, so you can get away with quite a bit of instrumentation. Unlike much of the rest of RCU. ;-)
Thanx, Paul
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