Support for Perf CTF traces now in master (was Re: FW: [RFC 0/5] perf tools: Add perf data CTF conversion)

[Alexandre Montplaisir <alexmonthy@voxpopuli.im>]

On 11/09/2014 08:31 PM, Alexandre Montplaisir wrote:
> On 2014-11-05 10:25 PM, Alexandre Montplaisir wrote:
>>
>>>
>>>> But if you could for example tell me the perf equivalents of all the
>>>> strings in that file, I could hack together such wrapper. With that,
>>>> in theory, perf traces should behave exactly the same as LTTng traces
>>>> in the viewer!
>>> Oooh, that would be awesome. So I installed maven but didn't get much
>>> further. Let me gather this for you.
>>
>> Awesome, thanks!
>>
>> I am travelling this week, so I'm a bit busy, but I will try to 
>> prototype a "wrapper" for the kernel analysis, and adding support for 
>> the perf events, whenever I have a chance. I'll keep you posted.
>
> Ok, some good news!
>
> I managed to get the CTF traces from perf working in Trace Compass! 
> See attached screenshots. This is showing the "ctf-out2" trace from 
> your previous email. The other trace seems to have less events 
> enabled, so it would only show some WAIT_FOR_CPU states in the view.
>
> If anybody wishes to try it, you can grab the whole branch ending at 
> https://git.eclipse.org/r/#/c/36200/ . Or run:
> $ git fetch 
> git://git.eclipse.org/gitroot/tracecompass/org.eclipse.tracecompass 
> refs/changes/00/36200/3 && git checkout FETCH_HEAD

Just a quick note, this branch is now merged to master. So anyone who 
pulls the code from the master branch at
git://git.eclipse.org/gitroot/tracecompass/org.eclipse.tracecompass.git
should be able to load perf-CTF traces in the viewer. The trace type is 
now called "Common Trace Format -> Linux Kernel Trace" and should 
support both LTTng kernel and perf traces in CTF format (although 
auto-detection should work in most cases).

This was based on the most recent file format I was aware of, we will 
update it accordingly if required.

Testing welcome!

Cheers,
Alexandre

>
> It reuses much of the code from the LTTng analysis, which is why it 
> was relatively quick to do. For now, it looks for the domain in the 
> CTF environment to be "kernel-perf". But this will be easy to update, 
> if needed, once the final format is decided.
>
> Maybe I missed it, but I couldn't find the system call names in the 
> trace. Using the sys_enter and sys_exit events, the viewer is able to 
> determine the kernel-mode states (in blue), but we cannot show the 
> exact system call names like we do with LTTng.
> There is also something weird with the arrows in the Control Flow View 
> (disabled in the screenshot), I don't know if it's due to the 
> particularity of the trace or to a bug in the view. We'll investigate.
>
> Feedback is very welcome.
>
> Cheers,
> Alexandre