[Intel-gfx] [RFC 00/17] Per-context and per-client engine busyness

[Tvrtko Ursulin]

On 25/10/2017 18:38, Chris Wilson wrote:
> Quoting Chris Wilson (2017-10-25 16:47:13)
>> Quoting Tvrtko Ursulin (2017-10-25 16:36:15)
>>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

>> I've prototyped a quick demo of intel-client-top which produces output like:
>>
>>      neverball[  6011]:  rcs0:  41.01%  bcs0:   0.00%  vcs0:   0.00%  vecs0:   0.00%
>>           Xorg[  5664]:  rcs0:  31.16%  bcs0:   0.00%  vcs0:   0.00%  vecs0:   0.00%
>>          xfwm4[  5727]:  rcs0:   0.00%  bcs0:   0.00%  vcs0:   0.00%  vecs0:   0.00%
> 
> +1
> +2 for a graph ;)

Where are those placement students when you need them! :)

>>> Another potential use for the per-client infrastructure is tieing it up with
>>> perf PMU. At the moment our perf PMU are global counters only. With the per-
>>> client infrastructure it should be possible to make it work in the task mode as
>>> well and so enable GPU busyness profiling of single tasks.
>>
>> ctx->pid can be misleading, as it set on creation, but the context can
>> be transferred over fd to the real client. (Typically that applies to
>> the default context, 0.)
> > Ok, I see that you update the pid when a new context is created. Still
> have the likes of libva that may use DRI3 without creating a context
> itself.

Hm, how rude of the protocol to provide this anonymization service!

I guess I could update on submission as well and then there is no escape.
 
> Back to the general niggle; I really would like to avoid adding custom
> i915 interfaces for this, that should be a last resort if we can find no
> way through e.g. perf.

I certainly plan to investigate adding pid filtering to the PMU. It is
supposed to be possible but I haven't tried it yet. Also not sure if it
will be exactly suitable for a top like tool. Will see if I manage to have
it working.

But what do you say about the simple per-context API (patch 13)? Do you
find using ctx get param for this acceptable or you can think of a different
way?

Regards,

Tvrtko