When exporting an image I got the messages seen below. Can anyone explain how to interpret this and tell me what should/could be done?
My laptop has the following specs:
Intel® Core™ i7-4510U CPU @ 2.00GHz 2.60 GHz with 8,00 GB RAM
4 GB NVIDIA GeForce GTX 850M
Default darktable settings (host memory limit = 1500):
78,257671 [default_process_tiling_cl_ptp] use tiling on module ‘atrous’ for image with full size 6034 x 4017
78,257671 [default_process_tiling_cl_ptp] (2 x 1) tiles with max dimensions 5480 x 4017 and overlap 512
78,257671 [default_process_tiling_cl_ptp] tile (0, 0) with 5480 x 4017 at origin [0, 0]
80,178557 [opencl_atrous] couldn’t enqueue kernel! -4
80,209799 [default_process_tiling_opencl_ptp] couldn’t run process_cl() for module ‘atrous’ in tiling mode: 0
80,209799 [opencl_pixelpipe] could not run module ‘atrous’ on gpu. falling back to cpu path
117,281491 [dev_pixelpipe] took 39,399 secs (139,109 CPU) processed `contrast equalizer’ on CPU with tiling, blended on CPU [export]
I tried some other settings for host memory limit and got the following results. The messages and results are all the same as above except for the message shown here:
Host memory limit = 2500
107,247154 [dev_pixelpipe] took 20,405 secs (67,156 CPU) processed `contrast equalizer’ on CPU with tiling, blended on CPU [export]
Host memory limit = 0 (no limitations)
69,119066 [dev_pixelpipe] took 13,615 secs (41,984 CPU) processed `contrast equalizer’ on CPU, blended on CPU [export]
I understand that contrast equalizer can’t run on GPU/OpenCl in this case. Why and what can be done about it?
I all situations contrast equalizer ran successfully on the CPU with tiling or without tiling (host memory limit = 0). What are the possible drawbacks of running darktable with host memory limit = 0?
The contrast equalizer performance was improved from 39,4 to 13,6 sec but the overall performance was only improved from 83,6 to 55,3 sec, so it is almost only contrast equalizer that benefits from the unlimited memory setting! The contrast equalizer must be very hard on memory!