Re: [RFC] perf/core: allow ftrace for functions in kernel/event/core.c

From: Song Liu
Date: Tue May 26 2020 - 17:47:18 EST




> On May 26, 2020, at 2:39 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Tue, May 26, 2020 at 02:28:26PM -0700, Song Liu wrote:
>> It is useful to trace functions in kernel/event/core.c. Allow ftrace for
>> them by removing $(CC_FLAGS_FTRACE) from Makefile.
>
> Did you try using the ftrace event with perf with this on?

I have tried a few things, like

perf stat -e probe:perf_read -I 1000
perf record -e probe:__x64_sys_perf_event_open -aR

They all work fine.

Do you have some tricky functions that we should double check?

Thanks,
Song