Some basic joblib questions...

[vgoklani]

Hi,

I just recently discovered joblib, and I had a few quick questions.

1. When I set n_jobs=-1 in multiprocessing, python uses 8 threads on my quad-core macbook pro. But with joblib.Parallel(n_jobs=-1), it appears to be using only 4 threads? This the same function, just called via joblib. The only reason I'm asking is that the sklearn random forests implementation (which presumably runs on top of joblib.parallel) uses all 8 threads. Am I doing something wrong?
2. How do you specify the "chunk size" using joblib.Parallel?
3. The kernel frequently dies when running joblib.Parallel in ipython notebook, although I've never had any such issues when running sklearn. Are there some tricks I should be aware of?

Thanks,

Vishal

[GaelVaroquaux]

1: don't know

2: there is no notion of chunk size. It might be a useful addition, but it's not there

1. Old versions of IPython notebook did not like forking. This has been fixed.