Messages in this thread | | | Date | Thu, 10 Dec 2009 08:08:00 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 2/4] ftrace - add function_duration tracer |
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* Tim Bird <tim.bird@am.sony.com> wrote:
> Add function duration tracer. > > Signed-off-by: Tim Bird <tim.bird@am.sony.com> > --- > kernel/trace/Kconfig | 8 > kernel/trace/Makefile | 1 > kernel/trace/trace.c | 32 ++ > kernel/trace/trace_duration.c | 527 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 568 insertions(+)
Please do it in a cleaner an more generic fashion: add a "function event" that perf can see and process, so all the output embellishment can be done outside of the kernel, in tools/perf/.
We want to wind down the current maze of ftrace plugins, not extend them. We already obsoleted the following ftrace plugins: scheduler, sysprof, blktrace, kmem, scheduler, etc. There's more work ongoing and broad agreement between folks developing it that this is the way forward.
The function tracer / function graph tracer is a holdout due to its complexity - but that by no means weakens the argument and the necessity to migrate it.
ftrace plugins were a nice idea originally and a clear improvement over existing alternatives, but now that we've got a technicaly superior, unified event framework that can do what the old plugins did and much more, we want to improve that and not look back ...
Thanks,
ingo
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