Re: Lockup in tracepoint unregister in sched switch ftrace plugin
From: Ingo Molnar
Date: Tue Oct 21 2008 - 08:09:37 EST
* Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> [ Paul, Thomas, wake up ]
> On Mon, 20 Oct 2008, Steven Rostedt wrote:
> > which calls unregister_trace_sched_switch define as macro to:
> > kernel/tracepoint.c: tracepoint_probe_unregister
> > " " : remove_tracepoint
> > kernel/rcupdate.c: rcu_barrier_sched
> > " " : _rcu_barrier
> > where it gets stuck at that "wait_for_completion".
> > I'm not sure if, because this is a scheduler trace point that we are
> > hitting some kind of race that is preventing the wait_for_completion to
> > finish, or what.
> Note, I just booted this kernel with CONFIG_NOHZ=n and it booted fine.
> This looks like a bug somewhere in tracepoints/RCU/dynamic-ticks
does it work with fb02fbc14 reverted? (see the reverter patch below or