Re: [darktable-devel] OpenMP benefit

2012-11-25 Thread AlicVB
Ok, thanks. and sorry for this "off topic" noise. AlicVB Le 25/11/2012 02:55, johannes hanika a écrit : > even though the threads are most likely held idle in the background > and not created new for every openmp loop, there will be an overhead > starting a parallel section. > > plus, if your loop

Re: [darktable-devel] OpenMP benefit

2012-11-24 Thread johannes hanika
even though the threads are most likely held idle in the background and not created new for every openmp loop, there will be an overhead starting a parallel section. plus, if your loop doesn't scale well, all threads have to wait for the slowest one, so you'll get synchronization overhead (likely

[darktable-devel] OpenMP benefit

2012-11-24 Thread AlicVB
Hi all, I have a question about OpenMP statement. While playing with that module, I find that borders doesn't use OpenMP in his process routine. I have tried to add some OpenMP statements, especially for the image blitting loop, at the end of the process, but perfs are worth... I understand it'