Line of code that fails with Intel driver, but works with AMD and NVIDIA.

[simone_t_1]

Hello,

following line of code (OpenCL C++ bindings 1.2) fails with Intel runtime 14.2 (on ArchLinux) -  (segmentation fault), but works with AMD and NVIDIA.

`cl_context_properties cps = getContext(queue).getInfo<CL_CONTEXT_PROPERTIES>()[1];`

Is this a bug in the Intel driver?

The context is created in this constructor:

https://github.com/AvtechScientific/ASL/blob/a14703fa5e4ec933248a5b9ed17ca719570ba6e5/src/acl/aclHardware.cxx#L50

Context properties are passed here:

https://github.com/AvtechScientific/ASL/blob/a14703fa5e4ec933248a5b9ed17ca719570ba6e5/src/acl/aclHardware.cxx#L74
https://github.com/AvtechScientific/ASL/blob/a14703fa5e4ec933248a5b9ed17ca719570ba6e5/src/acl/aclHardware.cxx#L81

Here is the getContext():

https://github.com/AvtechScientific/ASL/blob/a14703fa5e4ec933248a5b9ed17ca719570ba6e5/src/acl/aclHardware.cxx#L174

Everything fails on this line:
https://github.com/AvtechScientific/ASL/blob/a14703fa5e4ec933248a5b9ed17ca719570ba6e5/src/acl/aclHardware.cxx#L139

once called here with the queues being an Intel device
https://github.com/AvtechScientific/ASL/blob/a14703fa5e4ec933248a5b9ed17ca719570ba6e5/src/acl/aclHardware.cxx#L105

It looks like `getInfo<CL_CONTEXT_PROPERTIES>()` returns garbage...

Thank you.

[Robert_I_Intel]

Hi Simone,

Couple of questions:

1. Which OS are you running on? Which processor are you using?

2. Is it an option to move to 15.1 runtime? Do you see the same issues there?

3. Could you create a small reproducer together with the Makefile so I can try this on my system?

Thanks!

[simone_t_1]

Hi Robert,

thank you for the quick reply! I was told that this issue was fixed in 14.2 in Driver Version between 1.2.0.8 (which doesn't work) and 1.2.0.82248 (which does work). So if you can tell me in which exactly version the fix of getInfo<CL_CONTEXT_PROPERTIES> output happened - it would help, so I can put that info on the ASL's wiki; otherwise the issue seems to be not that urgent.

You may use ASL for HPC tests of your hardware - just an idea...

Thanks.

ST

[simone_t_1]

Hi Robert,

it's me again, could you, please, tell me where one can download Intel runtime with the driver version 1.2.0.82248. Is it 14.2 or 15.1? Or something else?

thank you.

[Robert_I_Intel]

Hi Simone,

From what I understand, you will need 14.2 as it is the only thing that will run on your system. I believe to run 15.1, you will need a specific version of OS (SLES or RedHat). You can get your drivers here: https://software.intel.com/en-us/articles/opencl-drivers

Please let me know if that worked for you.

[simone_t_1]

Arch has already this package installed and it doesn't work:

https://aur.archlinux.org/packages/intel-opencl-runtime/

Can you confirm that 15.1 has driver version 1.2.0.82248? I'm asking because the guy who got it working insisted that he had 14.2 (on RHEL 6.3 though). It's a bit strange - can 14.2 on Arch have 1.2.0.8 and on RHEL 6.3 - 1.2.0.82248??!!

Thanks.

[Robert_I_Intel]

According to release notes, 15.1 package should return 1.2.0.57 as the driver version (the correct version is actually 5.0.0.57). 14.2 does have a version 1.2.0.8, at least from what I can gather. Potentially, it could be that driver returns a different version depending on the hardware you are running, but I agree it would be a bit strange.

I believe what you want is the CPU driver from this package:

http://registrationcenter.intel.com/irc_nas/3809/intel_sdk_for_ocl_applications_xe_2013_r3_sdk_3.2.1.16712_x64.tgz