[Intel-gfx] [PATCH] drm/i915: add a tracepoint for gpu frequency changes

[Ben Widawsky]

On 2012-09-01 12:22, Chris Wilson wrote:
> On Sat, 01 Sep 2012 11:35:13 -0700, Ben Widawsky <ben at bwidawsk.net> 
> wrote:
>> I have no problem with Daniel's patch. It's just a matter of cutting
>> through some scheduler BS of "when the GPU wants to change 
>> frequency"
>> vs. "when we actually change the GPU frequency." I think *both* are
>> interesting.
>
> We already trace the interrupt, which has been invaluable in
> debugging. And there is no other source currently... :)
> -Chris

No we do not trace it (/me is looking on cgit, so perhaps a bit error 
prone). Sure we trace GT interrupts, but not pm interrupts (again, 
unless I am missing something via code browsing on the web).

Furthermore, even if we have added a generic interrupt trace event and 
I've missed it: I think it's still nice to have a power/performance 
specific one for users like powerTOP, as opposed to driver developers.

-- 
Ben Widawsky, Intel Open Source Technology Center