[Intel-gfx] [PATCH 0/4] prevent stalls due to tiling changes and bo reuse

[Chris Wilson]

On Thu, 22 Apr 2010 22:12:48 +0200, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> Hi all,
> 
> This patch-set prevents stalls due to bo reuse in libdrm. After having
> tried to fix the set_tiling stall both in libdrm and the kernel, I think
> fixing this in the kernel is the better option: This way gem nicely
> abstracts away the execution semantics. The only place where the
> asynchronous nature of the gpu leaks is in the busy ioctl, which userspace
> should call to check whether a mmap of the bo would stall.
> 
> Performance gains are minimal, but strictly positive (neglecting a 1% noise
> level).  cairo perf traces on my i945:
> 
> old: without-patches
> new: with-patches
> Speedups
> ========
>  xlib-rgba       firefox-planet-gnome-0    62418.67 (64895.61 1.98%) -> 57833.66
>  (61105.65 2.92%):  1.08x speedup

That's a little better than what I see here, but there is just about some
improvements over the noise.

The patches themselves look worthwhile cleanups.
-ickle

-- 
Chris Wilson, Intel Open Source Technology Centre