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    SubjectRe: [ANNOUNCE] New utility: 'trace'
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    On Wed, 2010-11-17 at 13:53 +0100, Frederic Weisbecker wrote:
    > On Wed, Nov 17, 2010 at 12:35:50PM +0100, Peter Zijlstra wrote:
    > > On Wed, 2010-11-17 at 09:30 +0100, Ingo Molnar wrote:
    > > > > For example I'm currently working with dozens of trace_printk() and I would be
    > > > > very happy to turn some of them off half of the time.
    > > >
    > > > I guess we could try such a patch. If you send a prototype i'd be interested in
    > > > testing it out.
    > >
    > > I don't see the point, the kernel shouldn't contain any trace_printk()s
    > > to begin with..
    >
    >
    > It's oriented toward developers. Those who use dozens of tracepoints in
    > their tree because they are debugging something or developing a new feature,
    > they might to deactivate/reactivate some of these independant points.
    >
    > This can also apply to dynamic_printk of course.
    >
    > Well, the very first and main point is to standardize trace_printk into
    > a trace event so that it gets usable by perf tools. I have been asked many
    > times "how to use trace_printk() with perf?".

    Thing is, since its these dev who add the trace_printk()s to begin with,
    I don't see the point in splitting them out, if you didn't want them why
    did you add them to begin with?!

    As to the trace_printk() to perf interface, you could do like mingo did
    and create a fake event and use the regular tracepoint interface, or
    hook it up directly and create a PERF_RECORD_TEXT field.

    Personally I like the trace_printk() as a TRACE_EVENT(printk), it also
    allows removing lots of the special casing concerning trace_printk from
    ftrace.




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