Description of problem: BOINC originally has ability to use multiple GPUs (including Intel/nvidia) for OpenCL calculation. However, F28 can utilize only one GPU at once for OpenCL. Version-Release number of selected component (if applicable): At least 7.8.x, 7.9.x, 7.10.x 7.11.0; ie. all the currently available versions. How reproducible: Install boinc-client on F28 computer with 2 or more nvidia/intel GPUs. Use boinc-manager to attach to OpenCL project(s). boinc requires <use_all_gpus>1</use_all_gpus> configuration in /var/lib/boinc/cc_config.xml to utilize multiple GPUs, however F28, this doesn't work. Only one GPU is used for OpenCL anyway. OTOH F27 works fine; multiple GPUs can be used in F27. F28 cannot do it.
Now I'm running F27, and after 9 or 10 hours of testing, boinc-client began to ignore multiple GPUs. It only uses one GPU again. I checked it with version 7.9 (coming with F27 package) and 7.11 (built from git).
The only thinkable remedy was to clear /var/lib/boinc directory and begin setting up, and it worked. It's very uneasy. It may be due to BOINC project, not to Fedora project.
Sorry, I forgot to write solution. It happens when the preference as to how many tasks should be stored is set to more than one day. If it's set to 1 day or less, this problem doesn't happen. Please close this issue.