bitbake: runqueue: Small performance optimisation

A minor performance optmisation to keep lists smaller when running large
builds. We can do this since once a task has been built, we don't need
to worry about it. This improves a major bottleneck that shows up on
performance profile charts in dryruns.

(Bitbake rev: cd6b89230823707c3c9bb9e6883bf5a971916581)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/runqueue.py

@@ -207,6 +207,8 @@ class RunQueueScheduler(object):
 
     def newbuildable(self, task):
         self.buildable.add(task)
+        # Once tasks are running we don't need to worry about them again
+        self.buildable.difference_update(self.rq.runq_running)
 
     def removebuildable(self, task):
         self.buildable.remove(task)