[Mesa-users] llvmpipe os mesa with my own llvm

burlen burlen.loring at gmail.com
Fri Jun 14 17:07:38 PDT 2013


On 05/24/2013 04:24 PM, Burlen Loring wrote:
> On 5/23/2013 1:09 PM, Burlen Loring wrote:
>> On 5/23/2013 6:57 AM, Brian Paul wrote:
>>> On 05/22/2013 04:40 PM, Burlen Loring wrote:
>>>> On 5/22/2013 9:02 AM, Brian Paul wrote:
>>>>> On 05/21/2013 04:43 PM, Burlen Loring wrote:
>>> Not sure what to say about the performance difference.  If the app 
>>> is dominated by vertex transformation, then varying LP_NUM_THREADS 
>>> might not make a lot of difference.
>
> still looking at why threading doesn't seem to be working as expected.

To close the loop on this, I found why threading wasn't working for me. 
It has nothing to do with Mesa. When running on the Cray XC30 the 
default CPU affinity used by the application launcher is "-cc cpu" where 
each process and any threads it creates are pinned to the same core. One 
has to either override this by passing the number of threads per process 
-d option, use numa node affinity "-cc numa_node" or disable the feature 
by passing the "-cc none" to the application launcher aprun.

also I tried a couple of runs using a larger dataset(54M tris), as you 
said with a large number of vertices to process the threading in the 
fragment pipeline helps only so much. Hopefully the vertex pipeline 
could be threaded in a future release. Are there plans for that?

Thanks
Burlen



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