Re: [PATCH 11/11] perf tools: Stop fallbacking to kallsyms for vdso symbols lookup

[Vinicius Costa Gomes]

Hi Jirka,

Jiri Olsa <jolsa@xxxxxxxxxx> writes:

> On Fri, Oct 26, 2018 at 04:19:52PM -0700, Vinicius Costa Gomes wrote:
>> Hi,
>> 
>> Adrian Hunter <adrian.hunter@xxxxxxxxx> writes:
>> 
>> > On 18/10/18 1:55 AM, Arnaldo Carvalho de Melo wrote:
>> >> From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
>> >> 
>> >> David reports that:
>> >> 
>> >> <quote>
>> >> Perf has this hack where it uses the kernel symbol map as a backup when
>> >> a symbol can't be found in the user's symbol table(s).
>> >
>> > I don't think this is a complete fix because it exposes new problems.
>> 
>> This commit broke function name resolution for 'perf record -g' for me.
>> 
>> What I mean is, with this commit applied:
>> 
>> $ ./tools/perf/perf record -g -- sleep 1
>> 
>> $ ./tools/perf/perf report
>> 
>> 'perf report' doesn't seem to be able to show the function names of the
>> trace.
>> 
>> If I revert this commit, function names are resolved fine.
>
> that commit just showed up some places where we have the
> ip resolve wrong.. would attached patch fix it for you?

Thank you for your patch.

I can some difference in the output, but I wouldn't say that it's fixed.

Here are some samples, if it's useful somehow:

https://gist.github.com/vcgomes/985626705e0968b973e426964f86a4b0

The "ping" tests were done running

$ sudo ./tools/perf/perf record -g -- ping -f -c 1000 127.0.0.1

And the "sleep" tests were done running

$ sudo ./tools/perf/perf record -g -- /bin/sleep 1


--
Vinicius