Re: [RFC] ftrace / perf 'recursion'

From	Steven Rostedt <rostedt@goodmis.org>
Newsgroups	linux.kernel
Subject	Re: [RFC] ftrace / perf 'recursion'
Date	2016-08-17 17:10 +0200
Message-ID	<s7aDE-2HU-5@gated-at.bofh.it> (permalink)
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On Wed, 17 Aug 2016 16:57:09 +0200
Peter Zijlstra <peterz@infradead.org> wrote:

> We'd still need the irq_work to wake tasks stuck in poll() and friends.
> And once we're over the watermark, every new event will trigger that
> wakeup, and the wakeup will generate a new event etc..

I just byte the bullet for those (first OS world) issues. If one wants
to trace wake ups, and the wake up of the trace task gets traced, which
causes the trace task to wake up more often, and add more events, then
so be it. I like to see how the tracer affects the system as well. I
noticed that hiding the tracer can make it confusing if one sees gaps
in the trace, where it was the tracer causing it.

-- Steve

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Thread

[RFC] ftrace / perf 'recursion' Peter Zijlstra <peterz@infradead.org> - 2016-08-17 11:30 +0200
  Re: [RFC] ftrace / perf 'recursion' Peter Zijlstra <peterz@infradead.org> - 2016-08-17 12:40 +0200
    Re: [RFC] ftrace / perf 'recursion' Peter Zijlstra <peterz@infradead.org> - 2016-08-17 13:00 +0200
      Re: [RFC] ftrace / perf 'recursion' Steven Rostedt <rostedt@goodmis.org> - 2016-08-17 15:50 +0200
        Re: [RFC] ftrace / perf 'recursion' Peter Zijlstra <peterz@infradead.org> - 2016-08-17 16:10 +0200
          Re: [RFC] ftrace / perf 'recursion' Steven Rostedt <rostedt@goodmis.org> - 2016-08-17 16:30 +0200
            Re: [RFC] ftrace / perf 'recursion' Peter Zijlstra <peterz@infradead.org> - 2016-08-17 17:00 +0200
              Re: [RFC] ftrace / perf 'recursion' Steven Rostedt <rostedt@goodmis.org> - 2016-08-17 17:10 +0200

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