I was trying to post this as a comment to the darktable blog, but
cannot find a way to create a comment; I'm posting here in the hopes
that it will be useful. Shall I post this on the flicker group and
Google+? Maybe it would be useful to include it on the darktable site,
too. Thanks everyone!
===
Summarising the discussion on darktable-users mailing list (main
contributors to the solution were Ulrich Pegelow and Federico Bruni):
darktable lost access to OpenCL upon upgrading to Ubuntu 14.04
('trusty thar') or Linux Mint 17.https://launchpad.net/~xorg-edgers/+archive/ubuntu/ppa contains up-to-date nvidia drivers; some older versions fail to compile darktable's OpenCL kernels (files that contain the GPU-accelerated image operations). Now, in order to make use of said OpenCL kernels, darktable needs the system library libOpenCL.so which must be accessible to the system's dynamic loader (ld.so). Reason is that the function flow is like this: darktable -> libOpenCL.so -> libnvidia-opencl.so.1 -> kernel driver -> hardware libOpenCL.so is contained in nvidia-opencl-dev libOpenCL.so will read the vendor-specific information file (ICD file) to find the library which contains the (vendor-specific) implementation. nvidia-opencl-icd-* contains both /etc/OpenCL/vendors/nvidia.icd and the library libnvidia-opencl.so.1 it points to. On my system, /usr/lib/x86_64-linux-gnu/libnvidia-opencl.so.1 is a symbolic link to libnvidia-opencl.so.331.89, which is the actual implementation. The required kernel modules are nvidia and nvidia_uvm; they are provided by the modules nvidia-331 and nvidia-331-uvm, respectively. You also need device files (/dev/nvidia*). The easiest way to set them up and make sure all modules are loaded is installing the nvidia-modprobe package (which, at the time of this writing, is only available for 'utopic', but works well with 'trusty' and Mint 17). Grab it at http://packages.ubuntu.com/utopic/nvidia-modprobe To summarise, the packages I have installed are: nvidia-331 / 331.89-0ubuntu1~xedgers14.04.2 nvidia-331-dev / 331.89-0ubuntu1~xedgers14.04.2 nvidia-331-uvm / 331.89-0ubuntu1~xedgers14.04.2 nvidia-libopencl1-331 / 331.89-0ubuntu1~xedgers14.04.2 nvidia-modprobe / 340.24-1 nvidia-opencl-dev:amd64 / 5.5.22-3ubuntu1 nvidia-opencl-icd-331 / 331.89-0ubuntu1~xedgers14.04.2 nvidia-settings / 340.24-0ubuntu1~xedgers14.04.1 nvidia-settings-304 / 340.24-0ubuntu1~xedgers14.04.1 nvidia-libopencl1-331 / 331.89-0ubuntu1~xedgers14.04.2 nvidia-opencl-dev:amd64 / 5.5.22-3ubuntu1 nvidia-opencl-icd-331 / 331.89-0ubuntu1~xedgers14.04.2 opencl-headers / 1.2-2013.10.23-1 My list of nvidia-related modules: nvidia, nvidia_uvm My nvidia-related device files: crw-rw-rw- 1 root root 195, 0 Jul 28 21:13 /dev/nvidia0 crw-rw-rw- 1 root root 195, 255 Jul 28 21:13 /dev/nvidiactl crw-rw-rw- 1 root root 250, 0 Jul 28 21:13 /dev/nvidia-uvm === On 28 July 2014 21:17, KOVÁCS István <[email protected]> wrote: > This was the final piece of the puzzle, now everything works without > installing modules manually or creating device nodes. After installing > nvidia-modprobe (note: it's only present in utopic, but has just 2 > dependencies, and is compatible with trusty and thus Mint 17) and > rebooting, I can now launch darktable with OpenCL enabled. > kofa@eagle:~ > lsmod|grep nvidia > nvidia_uvm 34855 0 > nvidia 10728548 30 nvidia_uvm > drm 302817 2 nvidia > kofa@eagle:~ > ls -l /dev/nvidia* > crw-rw-rw- 1 root root 195, 0 Jul 28 21:13 /dev/nvidia0 > crw-rw-rw- 1 root root 195, 255 Jul 28 21:13 /dev/nvidiactl > crw-rw-rw- 1 root root 250, 0 Jul 28 21:13 /dev/nvidia-uvm > > Thanks everyone! > > > On 28 July 2014 12:00, KOVÁCS István <[email protected]> wrote: >> Thanks! >> >> On 28 Jul 2014 11:35, "Federico Bruni" <[email protected]> wrote: >>> >>> Il 26.07.2014 21:25 KOVÁCS István ha scritto: >>> > Note: nvidia-modprobe is not shipped in the .deb files from the PPA >>> > >>> >>> but you have the deb package here: >>> http://packages.ubuntu.com/utopic/nvidia-modprobe >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Infragistics Professional >>> Build stunning WinForms apps today! >>> Reboot your WinForms applications with our WinForms controls. >>> Build a bridge from your legacy apps to the future. >>> >>> http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk >>> _______________________________________________ >>> Darktable-users mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/darktable-users ------------------------------------------------------------------------------ Infragistics Professional Build stunning WinForms apps today! Reboot your WinForms applications with our WinForms controls. Build a bridge from your legacy apps to the future. http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
