Re: [Intel-gfx] [PATCH v2 6/6] drm/i915: Improve hash function for the command parser

2015-11-20 Thread Ville Syrjälä
On Fri, Nov 20, 2015 at 10:56:01AM +, Chris Wilson wrote: > The existing code's hashfunction is very suboptimal (most 3D commands > use the same bucket degrading the hash to a long list). The code even > acknowledge that the issue was known and the fix simple: Do we have any statistics/some ea

[Intel-gfx] [PATCH v2 6/6] drm/i915: Improve hash function for the command parser

2015-11-20 Thread Chris Wilson
The existing code's hashfunction is very suboptimal (most 3D commands use the same bucket degrading the hash to a long list). The code even acknowledge that the issue was known and the fix simple: /* * If we attempt to generate a perfect hash, we should be able to look at bits * 31:29 of a comma