Regression caused by "drm/radeon: Don't increment pipe_id in kgd_init_pipeline"

[Oded Gabbay]

On 02/13/2015 12:01 PM, Michel Dänzer wrote:
>
> Hi Oded,
>
>
> the commit in the subject (5a8888a3119eb5b67f6e90605be9ed2e04807126)
> somehow causes degraded CPU (!) performance on my Kaveri box. E.g. a
> piglit run takes about 15% longer, and I suspect the same is true for
> e.g. compiling the kernel, though I haven't measured that explicitly.
>
> In addition to the measurably worse performance, the commit causes the
> CPU fan to stay significantly quieter during CPU-bound tasks, so maybe
> the commit somehow causes the CPU not to achieve turbo clocks or
> something like that.
>
> I'm attaching my .config. I don't see any difference in dmesg with or
> without the commit.
>
>
Hi Michel,
Thanks for catching that.
As we talked on IRC, there is indeed a bug in amdkfd.
I will publish the fix you tested to be included in 3.20 and mark it as stable.
I will also add piglit to my regression tests.

	Oded