Daniel Vetter <daniel.vetter@ffwll.ch> writes:

> Since we don't guarantee that objects stay at the same gtt offset,
> userspace needs to reload all indirect state anyway, even with hw
> contexts. The hw provides a little pipe_control flag to disable at
> least some these indirect state pointers and hence avoid to
> save/restore them at context switch time.
>
> Seems to improve hw context switch throughput as measured by running
> glxgears by about 0.5%, barely above the noise on my ivb gt2 here.

I'd like to see some better testing than picking an fps number out of
glxgears.  I'm dubious of there being any measurable effect here.  But
then, I haven't even been able to figure out from the specs what exactly
is considered to be "indirect state".