Keep GPU busy

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Chris Rampson

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Message 1742588 - Posted: 16 Nov 2015, 17:11:10 UTC

I want to keep my GPUs (GTX560Ti's) busy, but I always see some task grabbing ALL of the CPUs - while the GPUs are idle. What is the best strategy to keep those CUDA cores glowing? Thanks.
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Message 1742601 - Posted: 16 Nov 2015, 17:43:31 UTC
Last modified: 16 Nov 2015, 17:46:55 UTC

Runnning stock (openCL) under Linux on host 6415298

edit: you'll need to enable a bunch of log flags. also when the GPU sits idle. do you actually have GPU tasks on the system?

are you keeping a core free to feed the GPU? (is that necessary under linux too?)
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Richard Haselgrove Project Donor
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Message 1742610 - Posted: 16 Nov 2015, 18:04:25 UTC - in response to Message 1742601.  
Last modified: 16 Nov 2015, 18:06:43 UTC

do you actually have GPU tasks on the system?

Yes, he does. Currently from both SETI and Milkyway, and recently from Einstein and GPUGrid.

I suspect that the answer may involve the Milkyway N-Body MT tasks, most recently reported complete about 30 minutes ago.

And it may also involve asking whether an upgrade beyond BOINC version 7.2.42 is available from his distro.
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Message 1742614 - Posted: 16 Nov 2015, 18:18:33 UTC - in response to Message 1742610.  

I can upgrade to the latest BOINC version (standard 64bit Linux). Milkyway does love grabbing all 8 CPUs while CUDA sleeps ...
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Message 1742617 - Posted: 16 Nov 2015, 18:29:15 UTC - in response to Message 1742614.  

Actually, the BOINC version is probably OK - the bug I was worried about was fixed round about version 6.12.6

This may well involve poring over the debug logs - specifically <cpu_sched_debug>. I'll let William guide you through that - he's been away from the boards for a while, and was wanting to find his feet again (probably tomorrow morning, European time, now).
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Profile Mike Special Project $75 donor
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Message 1742663 - Posted: 16 Nov 2015, 22:55:33 UTC - in response to Message 1742601.  

Runnning stock (openCL) under Linux on host 6415298

edit: you'll need to enable a bunch of log flags. also when the GPU sits idle. do you actually have GPU tasks on the system?

are you keeping a core free to feed the GPU? (is that necessary under linux too?)


Yes, it is necessary,especially with an AMD FX CPU.


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Message 1742814 - Posted: 17 Nov 2015, 10:17:07 UTC - in response to Message 1742614.  
Last modified: 17 Nov 2015, 10:31:02 UTC

I can upgrade to the latest BOINC version (standard 64bit Linux). Milkyway does love grabbing all 8 CPUs while CUDA sleeps ...

yes, please.

and then please enable the cpu_sched_debug log flag in cc_config.xml.

There should be a convenient 'event log options' under 'options' to enable and disable log flags.
You will have to let it run until the problem occurs and then post the relevant part of the log.

Also, while the milkyway (MW) mt task is running have a look in the advanced view of BOINC manager if there are entries on CPU/GPU usage.


edit: @ Mike Thanks. I figured, but prefer to ask when uncertain. Nothing worse than disseminating incorrect tech info.
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Message 1751551 - Posted: 24 Dec 2015, 18:14:43 UTC

There are no controls for telling BOINC to use the CUDA device. I rarely ever see both GPUs working at the same time. I think I need to build a second computer and have a single GPU in each ...
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Message boards : Number crunching : Keep GPU busy


 
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