[Intel-gfx] patches for occlusion query fix on sandybridge

[david may]

Hello Eric,

Tuesday, December 14, 2010, 5:58:58 PM, you wrote:

> On Tue, 14 Dec 2010 12:55:59 +0800, Zhenyu Wang <zhenyuw at linux.intel.com> wrote:
>> It appears Sandybridge PIPE_CONTROL write out buffer need
>> to be set as cached, currently LLC cached, in order to read
>> back correct counter. Otherwise I can always be possible to
>> get corrupted 64-bit PS_DEPTH_COUNT from PIPE_CONTROL write.
>> 
>> So below patches try to add new flag during bo create with
>> cacheable type, to be sure that GTT entry's cache bits would
>> be setup for that.
>> 
>> This fixes occlusion query piglit test and mesa demos on my
>> sandybridge. Note that below patches don't include necessary
>> component version check changes.

> Why don't we just keep all of our BOs LLC cached?  This was supposed to
> be a big win of the new chipset, as it means we don't need to clflush.


Ohh,the implication here is that people are/have been writing the
code,But Not bothering Actually benching/Profiling it to see if it actually is faster and
 better throughput than before, that seems wrong, especially given sandy bridge is
 supposed to be better, i Do Hope you are/will be testing/benching/Profiling
  to see if it/all SB Code is actually  "a big win" one way or the other before passing for
 release.

-- 
Best regards,
 david                            mailto:david.may10 at ntlworld.com