Messages in this thread | | | Date | Sat, 20 Sep 2008 10:37:28 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: Reading EeePC900 battery info causes stalls (was Re: How how latent should non-preemptive scheduling be?) |
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On Sat, 20 Sep 2008, Sitsofe Wheeler wrote:
> Steven Rostedt wrote: > > The wake up tracing is CONFIG_SCHED_TRACER. If you do not see "wakeup" as > > one of the available tracers in available_tracers, then check > > your dmesg and see if you have CONFIG_FTRACE_STARTUP_TEST enabled. There was > > a known bug that would cause the wakeup tracing to fail the test. When a > > trace fails the startup test, it is disabled. > > This is exactly the case (dmesg reports the ftrace wakeup startup test > failed). That's what I get for not reading my dmesg more carefully...
OK, that is probably the known bug you are hitting. Simply disable the CONFIG_FTRACE_STARTUP_TEST and you should have the wakeup tracer. The bug is with the test, not the tracer, so it should not hurt you.
-- Steve
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