Re: [PATCH 0/5][RFC] [RFC] function profiler

[Ingo Molnar <mingo@elte.hu>]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> The following patches are RFC, and to discuss is this work would be
> useful.
> 
> This patch series adds a function profiler hook to the function tracer
> and function graph tracer. That is, it uses the mcount calls to track the
> functions being called. Now with the function graph tracer it also
> keeps track of the times the functions have been executing.
> 
> Note, this is similar to oprofile, but is not a sampling approach, but
> a true recorder. Of course, by recording every function the overhead
> compared to oprofile is higher. With the use of dynamic ftrace, you could
> just trace certain functions, or just a certain module. The flexibility
> is a bit greater with this profiling.
> 
> The last patch adds another feature to the function graph. It gives
> the ability to only trace the amount of time inside a function and
> not the amount spent in sub functions that are also recorded. That is,
> if A calls B, you can decide if the time spent in A should include the
> time spent in B. This is an option added to trace_options.
> 
> Again, this is all RFC, but if there is any interest in having this
> feature, prehaps we should include it.
> 
> -- Steve
> 
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: rfc/tip/tracing/function-profiler
> 
> 
> Steven Rostedt (5):
>       tracing: add function profiler
>       tracing: move function profiler data out of function struct
>       tracing: adding function timings to function profiler
>       tracing: make the function profiler per cpu
>       function-graph: add option to calculate graph time or not
> 
> ----
>  include/linux/ftrace.h               |    3 +-
>  kernel/trace/Kconfig                 |   15 +
>  kernel/trace/ftrace.c                |  558 +++++++++++++++++++++++++++++++++-
>  kernel/trace/trace.c                 |   15 +-
>  kernel/trace/trace.h                 |    4 +-
>  kernel/trace/trace_functions_graph.c |   25 ++-
>  kernel/trace/trace_output.c          |   10 +
>  kernel/trace/trace_output.h          |    2 +
>  8 files changed, 608 insertions(+), 24 deletions(-)

Pulled into tip:tracing/profiling, thanks Steve!

	Ingo