[Mesa-dev] [PATCH 17/17] i965: Disentangle batch and state buffer flushing.

[Chris Wilson]

Quoting Kenneth Graunke (2017-09-06 01:09:50)
> We now flush the batch when either the batchbuffer or statebuffer
> reaches the original intended batch size, instead of when the sum of
> the two reaches a certain size (which makes no sense now that they're
> separate buffers).
> 
> With this change, we also need to update our "are we near the end?"
> estimate to require separate batch and state buffer space.  I obtained
> these estimates by looking at the size of draw calls in the Unreal 4
> Elemental Demo (using INTEL_DEBUG=flush and always_flush_batch=true).
> 
> This will increase the batch size by perhaps 2-4x, which will almost
> certainly have a performance impact, and may impact overall system
> responsiveness.
> 
> XXX: benchmark, may need a lot of tuning.

What were you thoughts to not flushing the batch on swapping the state,
since that just needs to re-emit STATE_BASE?
-Chris