[Mesa-dev] [PATCH 05/18] i965: Reuse our VBO for streaming fast-clear vertices

[Chris Wilson]

On Tue, Jul 07, 2015 at 01:42:47PM +0300, Martin Peres wrote:
> On 06/07/15 19:43, Kenneth Graunke wrote:
> >On Monday, July 06, 2015 11:33:10 AM Chris Wilson wrote:
> >>Rather than allocating a fresh page every time we clear a buffer, keep
> >>that page around between invocations by tracking the last used offset
> >>and only allocating a fresh page when we wrap.
> >>
> >>Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> >>---
> >>  src/mesa/drivers/dri/i965/brw_meta_fast_clear.c | 17 ++++++++++++++---
> >>  1 file changed, 14 insertions(+), 3 deletions(-)
> >This looks okay to me.  Do you have any performance data to justify the
> >extra complexity?
> 
> I actually get a negative performance improvement on a customer
> benchmark (-1.3%). Could it be because we are waiting on the VBO at
> some point?
> 
> What benchmark did you try to get a perf improvement?

For this something as simple and cpu bound as windowed glxgears:
14550 -> 15400 (+-30fps both sides).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre