[Mesa-dev] [PATCH 2/6] i965/sync: Stop cacheing fence's signal status

[Chad Versace]

On Sun 02 Oct 2016, Kenneth Graunke wrote:
> On Tuesday, September 27, 2016 11:51:20 PM PDT Chad Versace wrote:
> > Cacheing the signal status complicates the code for questionable
> > performance benefit. I added the cacheing long ago, and I now think it
> > was the wrong decision.
> > 
> > When we later add support for fences based on sync fds (that is, a fd
> > backed by struct sync_file in Linux 4.8), the cacheing becomes even more
> > hairy. So it's best to eliminate it now.
> > ---
> >  src/mesa/drivers/dri/i965/intel_syncobj.c | 27 ++-------------------------
> >  1 file changed, 2 insertions(+), 25 deletions(-)
> > 
> 
> Aside from making it faster to answer repeated "is it done yet?" queries
> (which I agree is of dubious value)...this also makes it possible to
> release batch_bo earlier.  Now you have to keep it around until the
> fence object is destroyed.  That seems less than ideal?

That's fair. To reduce the controversy in this patch series, I'll submit
a v2 without this patch.