Re: perf's handling of unfindable user symbols...

From: Masami Hiramatsu
Date: Wed Oct 17 2018 - 04:22:32 EST

On Tue, 16 Oct 2018 15:45:06 -0300
Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:

> So, I thought something had changed and in the past we would somehow
> find that address in the kallsyms, but I couldn't find anything to back
> that up, the patch introducing this is over a decade old, lots of things
> changed, so I was just thinking I was missing something.
> I tried a gtod busy loop to generate vdso activity and added a 'perf
> probe' at that branch, on x86_64 to see if it ever gets hit:
> Made thread__find_map() noinline, as 'perf probe' in lines of inline
> functions seems to not be working, only at function start. (Masami?)

Thank you for reporting it. Hmm, what happened when you did it?
I checked some points, but seems no problem.
(Would you see no line number? or defined event didn't work?)

Thank you,

Masami Hiramatsu <mhiramat@xxxxxxxxxx>