[Beignet] Graphical Glitches and Local Memory Performance Issue

[Pan, Xiuli]

Hi,

Could you make this as a bug report to Beignet on https://bugs.freedesktop.org/
It will help us to track the status and you can also provide some more information and reproduce codes.

As for the Local buffer type, it seems to be our query API's bug. Our implementation does not use the global buffer as local memory. We will have a patch fix it.
 
Thanks
Xiuli

-----Original Message-----
From: Beignet [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of Artyom Beilis
Sent: Sunday, January 22, 2017 5:38 PM
To: beignet at lists.freedesktop.org
Subject: [Beignet] Graphical Glitches and Local Memory Performance Issue

Hello,

I'm trying to use Beignet driver to use OpenCL:

I have tested in on two platforms:

Platform #1  i5-3470 with Intel® HD Graphics 2500
--------------------------------------------------------------------------

Some of clinfo output:

  Platform Profile:                              FULL_PROFILE
  Platform Version:                              OpenCL 1.2 beignet 1.3
  Platform Name:                                 Intel Gen OCL Driver
  Platform Vendor:                               Intel
  ...
  Local memory type:                             Global
  Local memory size:                             65536
  ...
  Unified memory for Host and Device:            1
  ...
  Name:                                          Intel(R) HD Graphics
IvyBridge GT1
  Vendor:                                        Intel
  Device OpenCL C version:                       OpenCL C 1.2 beignet 1.3
  Driver version:                                1.3

I tested both beignet 1.2.1 and now recent 1.3 using Linux 4.4

The biggest issue is immediate graphical glitches I get when I start an OpenCL program including clinfo. So even when computation complete fine the GUI becomes unusable until reboot.

-------------------------------------------------------------
Platform #2  i5-6600 with Intel® HD Graphics 530

Works OK but significantly slower than using same GPU under Windows with Intel OpenCL drivers.

The biggest hit that I see in profiling comes from reduction - use of local memory is very slow:
I see same:
  -----------
  Local memory type:                             Global
  --------

On beignet 1.2.1 - using Global memory for local simulation gives significant performance reduction and makes the performance mush slower for comparable CPU implementation

On Windows OpenCL implementation I see that the Local memory type is Local and performance is much better.

Question:

1. Is there any fix for graphical glitches that occur?
2. Is there a way to enable Local memory support as LOCAL memory and not Global.


Thanks,
   Artyom
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