[Intel-gfx] Supporting Intel GPU tracing in gpuvis

[Pierre-Loup A. Griffais]

On 09/06/2017 12:45 PM, Michael Sartain wrote:
> On Wed, Sep 6, 2017, at 03:09 AM, Chris Wilson wrote:
>> We already have those tracepoint equivs and a script to generate a
>> similar visualisation: intel-gpu-tools/scripts/trace.pl, but only
>> looking at the scheduling issue from the gpu pov. But it's really only a
>> dev toy atm, plugging the gap between userspace and the gpu has been on
>> the perennial wishlist.
> 
> Ah, cool. I'll take a look at the events in trace.pl and try doing some
> captures with it on my intel laptop.

Yep, thanks, that's helpful; not sure why I got dropped there but Mike 
kindly re-added me (am not on intel-gfx).

Since you called out many more events than we were expecting, should we 
assume the situation is not quite as simple as amdgpu where we have a 
tracepoint for work getting queued on HW pipes, and a tracepoint for 
work finishing? With the tracepoint in the initial ioctl for work 
submission and the appropriate seqnos, just these three let us 
reconstruct the whole timeline for all HW pipes, and attribute it to a 
userspace process. I understand that last one does not yet exist for 
Intel, as you pointed out. If you had any pointers on where to add it, 
maybe we could prototype something, but not sure how much work we'll be 
able to do directly on Intel HW.

Thanks,
  - Pierre-Loup

> 
> Thanks for the pointer Chris.
>   -Mike
>