Hello Ulrich, I've noticed the same thing. It's definitely related to ubuntu 16.04. I store my images on an NFS share, and ubuntu wants to use NFS version 4. My host doesn't support version 4, so in order to avoid the apparently really slow negotiation, I sped things up a LOT by specifying option "nfsvers=3" in fstab:
999.999.9.999:/host_path /client_path nfs auto,nfsvers=3 0 0 This didn't totally solve the problem. It's still slower than before, but it's workable now. I hope this is helpful, Pete Hall On 09/09/2016 01:55 PM, Ulrich Pegelow wrote: > Hi, > > Am 09.09.2016 um 17:25 schrieb Aurélien PIERRE: >> since Ubuntu 16.04, the processing and exporting with OpenCL felt much >> slower than before. > [...] >> >> Any clues ? > > Not really. However, one thing is obvious: > > [opencl_profiling] spent 124,9889 seconds in [Write Image (from host > to device)] > [opencl_profiling] spent 35,1145 seconds in [Read Image (from device > to host)] > > All time is lost while transferring data between host memory and GPU > memory. That step is known to be timing critical but in your case it's > agonizingly slow. > > No idea what causes this slowdown. Knowing that you changed your > system I'd suspect the driver to be the culprit. > > Ulrich > > > > ___________________________________________________________________________ > > darktable developer mailing list > to unsubscribe send a mail to > [email protected] > -- Pete Hall [email protected] 608-290-0731
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