scikit-learn/scikit-learn — pull request #2681 by ogrisel (2013-12-20 18:26:08+00:00)
Title: Upgrade to Joblib 0.8.0a and use the threading backend for parallel fitting of forests

This brings very nice memory improvements to fitting random forests.

The new memory mapping support should also make it possible to improve the memory usage of parallel grid search and cross validation although not as drastically because of the memory copy caused internally by the fancy indexing of the data with the train / test indices.