Re: Fw: Re: Re: Howto make perf probe work

[Namhyung Kim <namhyung@kernel.org>]

> >HI,
> >Please enable kprobe_event config option in the kernel and build the same
> >and boot the board using it. Then please try to add event using perf probe
> >command
> 
> Thanks very much for your reply, and I already enable DEBUG_KPROBE_EVENT in kernel.
> I did success in "perf probe handle_mm_fault".
> 
> But when i want to to "perf probe" other Kernel symbol, such as do_page_fault.
> I came across other problems:
>     Added new event:
>     Failed to write event: Invalid argument
>     Error: Failed to add events. (-1)
> And when i type perf probe page_fault_entry:
>     Kernel symbol 'page_fault_entry' not found.
>     Error: Failed to add events. (-2)
> Please notice that "do_page_fault" and "page_fault_entry" are all Kernel symbols, which canbe find in  "/proc/kallsyms", but not recorgonized by perf (or even kprobe).
> Any idea for that?

For some reason, do_page_fault() is marked as __kprobe on some arch
which means it cannot be probed.

Thanks,
Namhyung