Problem with Batch Queue multi core processing

[Maik Qualmann]

This problem is fixed in digiKam-5.8.0. The thread support for libraw was not 
activated, it only affects NEF files.

See here:

http://digikam.1695700.n4.nabble.com/Batch-RAW-Conversion-to-jpg-leads-to-unusable-jpg-tiff-when-using-all-kernels-td4703791.html

Maik

Am Samstag, 23. September 2017, 22:44:21 CEST schrieb Robert Zeller:
> Gilles,
> 
> My system has a 6 core CPU with 16 GB of main memory; OS is openSUSE
> Leap 42.3, I am running DK 5.7.0-178.7 as provided by SUSE distribution.
> 
> I am encountering a problem with multi core processing in BQM when
> converting NIKON raw files and using all 6 cores; BQM is using the
> following workflow:
> 
> Color Auto-correction
> 
> Sharpen Image
> 
> Color Effects
> 
> Convert to JPEG
> 
> This works fine with just ONE image in the run-Queue and "Work on all
> processor cores" enabled. With more than one image in the queue I only
> get a pattern of fine lines in RGB colors in the resulting jpegs .
> Disabling "Work on all processor cores" I get correct results for all
> pictures, but clearly at the prize of loosing all the possible speedup
> of the 6 cores.
> 
> With all cores enabled I can see that every core is allocating its one
> memory, and there is definitely enough memory on my system.
> 
> Could it be, that for some reason the memory gets mixed up among the six
> running jobs? Or am I doing something  wrong?
> 
> Best regards,
> 
> Robert Zeller