Re: Reading perf counters at ftrace trace boundaries

zhangwei(Jovi)
2013-08-12T02:25:21Z

On 2013/8/12 8:03, Karim Yaghmour wrote:
>
> Wondering if there's a way for reading perf counters in the kernel. I'd
> like to read/record perf counters on ftrace function tracing
> entries/exits to provide a rundown of the value of various counters on
> function call boundaries.
>
> [ Steven: apologies for sending you a duplicate here of what I somewhat
> already sent privately. ]
>

If you want to base on ftrace, below two approach maybe take into use:

- register_ftrace_function/unregister_ftrace_function

- perf_event_create_kernel_counter (function event id is 1)

the first one is simplest, IMO.

You need to write your own kernel module to use these approach.

jovi.