tree 08d6739686d1e032d8586ac081561df0cddf0cd7
parent ed13033f0287051577bc1678cde63a42fa419f3c
author Chris Wilson <chris@chris-wilson.co.uk> 1471537034 +0100
committer Chris Wilson <chris@chris-wilson.co.uk> 1471556219 +0100

drm/i915/cmdparser: Improve hash function

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 command from a batch buffer and use the full mask for that
 * client. The existing INSTR_CLIENT_MASK/SHIFT defines can be used for this.
 */

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-35-chris@chris-wilson.co.uk