Messages in this thread | | | Subject | Re: timer: lockup in run_timer_softirq() | From | Steven Rostedt <> | Date | Thu, 11 Jul 2013 12:59:32 -0400 |
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On Thu, 2013-07-11 at 12:55 -0400, Steven Rostedt wrote:
> > > > Other than that, a function tracer environment that is safer to use might be > > useful for other people as well. > > Not sure how to make the environment safe, as the main purpose of the > function trace is to debug those hard to debug locations, like NMIs, > RCU, dynamic ticks, etc. To ensure a "safe" environment, it would > cripple the tracer. > > Hmm, what would you state as a safe environment? How can we detect if > the environment is safe to trace or not?
Maybe I misunderstood you. You mean to have this environment be something for not just perf, and have the macro be:
NONSAFE_TRACE(__local_bh_enable);
?
Then, any ftrace user could set a flag in the registering of its ops to 'safe_only_functions'. And it will ignore all of these locations. There's really not many of them, so it may not be too hard to weed out.
-- Steve
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