Idle docker using 100% cpu

Expected behavior

When idle cpu usage should remain low.

Actual behavior

Occasionally when idle I notice that see my cpu go to 100% (I notice because my CPU fan starts going)
This is when I am not actively using docker - its just running in the task bar. Closing and restarting makes the issue disappear.



Docker for Mac: version: mac-v1.12.0-beta18-3-gec40b14
OS X: version 10.11.5 (build: 15F34)
logs: /tmp/20160710-105202.tar.gz
[OK] docker-cli
[OK] app
[OK] menubar
[OK] virtualization
[OK] system
[OK] osxfs
[OK] db
[OK] slirp
[OK] moby-console
[OK] logs
[OK] vmnetd
[OK] env
[OK] moby
[OK] driver.amd64-linux

Steps to reproduce the behavior

I cannot reliably reproduce this - but I have seen it on several occasions.