Messages in this thread | | | Subject | Re: [PATCH 2/4] ftrace - add function_duration tracer | From | Steven Rostedt <> | Date | Thu, 10 Dec 2009 09:29:27 -0500 |
| |
On Thu, 2009-12-10 at 13:03 +0100, Frederic Weisbecker wrote:
> This makes me feel I'm going to try converting the function graph tracer > into an event during the next cycle. It does not mean I could make it > usable as a perf event right away in the same shot that said, as you can > guess this is not a trivial plug. The current perf fast path is not yet > adapted for that.
I curious how you plan on doing this. The current event system shows one event per trace point. A straight forward approach would make every entry and exit of a function a trace point and that would lead to a very large kernel to handle that.
Perhaps we could abstract out all entries and exits. We need to be able to link to a single point (entry or exit) not all. This also has the added issue of using the ftrace infrastructure of nop the mcount call. We also need a way to enable a set of functions.
We may be able to abstract this out, but I'm hesitant on making this the only interface.
-- Steve
| |