DOC: updating GridSearchCV's n_jobs parameter

accraze · accraze · commit 2a7ab7d0a767 · 2016-12-22T16:50:28.000-08:00
fixes scikit-learn#5797
diff --git a/sklearn/grid_search.py b/sklearn/grid_search.py
@@ -670,9 +670,20 @@ class GridSearchCV(BaseSearchCV):
     fit_params : dict, optional
         Parameters to pass to the fit method.
 
-    n_jobs : int, default=1
-        Number of jobs to run in parallel.
-
+    n_jobs: int, default: 1 :
+        The maximum number of concurrently running jobs, such as the number of 
+        Python worker processes when backend=”multiprocessing” or the size of 
+        the thread-pool when backend=”threading”. 
+
+            - If -1 all CPUs are used. 
+        
+            - If 1 is given, no parallel computing code is used at all, 
+              which is useful for debugging. 
+       
+            - For n_jobs below -1, (n_cpus + 1 + n_jobs) are used. 
+
+            - For n_jobs = -2, all CPUs but one are used.
+    
         .. versionchanged:: 0.17
            Upgraded to joblib 0.9.3.
 
