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1663 Discussions

Disable TBB on CPU fallback

Alexander_Herz
Beginner
270 Views

Hi,

I have a slightly obscure problem :) For testing purposes we're running opencl inside a linux VM, so the actual gfx hardware is not accessable. We're using the CPU fallback from intel's opencl impl instead. Apparently, this impl is using TBB to get better performance but our environment does not allow for third parties to create any threads. We don't need any performance, just that it works at all. Is there a way (maybe by setting an environment variable) to disable the multi-threading inside intel's CPU based opencl driver?

Thx, Alex

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6 Replies
Raghupathi_M_Intel
270 Views

I believe that's not possible. You may be able to play with global and local sizes to restrict the number of threads but the runtime still depends on tbb. I will fwd your question to see if there are workarounds.

Raghu

Raghupathi_M_Intel
270 Views

Ok. Looks like there is no way to disable TBB.

Yuri_K_Intel
Employee
270 Views
Hi Alexander, Is it possible to adjust VM settings so it uses only 1 core (without HT)? Probably this will prevent TBB from creating new threads. Thanks, Yuri
Maxim_S_Intel
Employee
270 Views
Alexander_Herz
Beginner
270 Views

Great, immidate exec seems to fix my problem.

I assume the standard TBB ENV vars also work here?

Regards,

Alex

Raghupathi_M_Intel
270 Views

Thanks Max. I wasn't aware of the extension. Moreover I misunderstood the question as "completely disabling tbb".

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