cancel
Showing results for 
Search instead for 
Did you mean: 

Archives Discussions

evk8888
Journeyman III

Task Parallelism in OPENCL

Trying to use clEnqueueTask to get parallelism in a 24 core machine

Hello all,

I am trying to run 5 different kernels on a 24 core cpu machine (24 compute units). I am using clEnqueueTask() to queue all the kernels to the cpu. This should theoritically use 5 cores on the cpu but uses only 1 core all the time. Interestingly if i am using different queues then the usage goes up to 2-3 cores but not the maximum. 

I would like to know if anybody as used task parallelism in opencl kindly throw some light to my problem...

thanks

0 Likes
6 Replies
nou
Exemplar

of course. task are serialized in one queue. you can get parallel task if you turn out-of-order queue which is not currently supported.

0 Likes

evk8888,

I do not think running different kernels concurrently is supported( atleast that is the case for ATI gpus). Are you using device fission extension?

Can you provide more information about your system configuration.

0 Likes

I have the queue in out of order enabled mode only, but it does not seem to use this feature. is it supported ?

Machine features are

Vendor: GenuineIntel
Device Name: Intel(R) Xeon(R) CPU           E7450  @ 2.40GHz
Max Work Group Size: 1024
Max Compute Units: 24

do you have any examples of this device fission technique?? I tried it but doesnt seem work right for me.

 

thanks

0 Likes

I would suspect both device-fission and out-of-order exec are highly architecture dependant, so I doubt you will be able to achieve what you want with StreamSDK.

Intel OpenCL SDK might have better support for harnessing all cores of Xeons in this manner.

But if anyone knows better, feel free to correct me.

0 Likes

i think meteor head is right . IIRC intel xeon is actually a 12 core CPU which appears as a 24 core CPU to OS using hyperthreading.

It would be nice if you can post the results from intel SDK.

0 Likes

Thanks guys. let me try doing tht.. also can anyone post some examples for device fission..

 

thanks

vinoth

0 Likes