I run android emulator on both Windows 7 and fedora 20 slaves. They all have the problem where the android emulator related job can't utilize all executors on a slave. I configured all jobs to run on specific slaves and slaves to only run jobs specific to that slave. The problem is a little different for launching new emulators versus launching existing emulators.

• For jobs that creates and launch new emulators, there can only be one of them running on a slave. Any other jobs on the same slave will wait for next executor no matter how many available executors are there on the slave
• For jobs that launches existing emulators, there seems to be a 7 concurrent jobs limit. I have a very powerful slave machine that I give it 15 executors, and tried to run 10 jobs concurrently. However, only 7 of them were run, and the other 3 were waiting for available executor.