[Intel-gfx] [PATCH 3/3] drm/i915: HSW GT3 Slices: Userspace can dynamically forcibly enable all slices

[Rodrigo Vivi]

please ignore this one and other two (libdrm and igt) with exec
flag... will do a v2 and resend soon..

On Tue, Oct 15, 2013 at 1:14 PM, Eric Anholt <eric at anholt.net> wrote:
> Rodrigo Vivi <rodrigo.vivi at gmail.com> writes:
>
>> Rendering buffers that need full GT power can request full power through
>> this I915_EXEC_GT_FULL flag. If the default is the power saving with half
>> slices off it executes LRIs to immediately enable all slices.
>
> How is userspace supposed to decide that the GPU needs to be at full
> power?  Power management is a system problem which wants awareness of
> the total load on the GPU from all clients, not just 1.  The kernel can
> get that information, but userspace can't.
>
> Basically, if you give userspace this knob, userspace will just have to
> set it on every batchbuffer.  At which point, why give them the knob at
> all?



-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br