Messages in this thread | | | Date | Mon, 20 Oct 2008 23:48:48 -0400 (EDT) | From | Steven Rostedt <> | Subject | Lockup in tracepoint unregister in sched switch ftrace plugin |
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Mathieu,
I just downloaded the latest git repo from Linus's tree, and the sched_switch start up test locks up. I traced it down to the first unregister of a trace point. Here's the call path that I see.
kernel/trace/trace.c: register_tracer kernel/trace/trace_selftest.c: trace_selftest_startup_sched_switch kernel/trace/trace_sched_switch.c: sched_switch_trace_ctrl_update " " : stop_sched_trace " " : tracing_stop_cmdline_record " " : tracing_stop_sched_switch " " : tracing_sched_unregister
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.
I'll look more at it tomorrow.
-- Steve
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