High CPU utilisation when modifying host FS shared with container

Expected: no performance degradation on host

CPU usage spike when host FS is modified and volume is shared with guest

Steps to reproduce the behavior

  1. docker run --privileged=true --name=build -a stdin -a stdout -a stderr -it -v $HOME/somedir:/src ubuntu bash
  2. host: cd somedir; svn co some-large-repository
  3. open Activity Monitor

Activity Monitor shows:

com.docker.hyperkit  154%
com.docker.osxfs      48%
kernel task           25%
svn                   20%
iTerm2                13%

I can’t be certain, but it seems there’s causation here, shared volume modifications somehow trigger docker activity.

pinata diagnose -u
OS X: version 10.11.5 (build: 15F34)
Docker.app: version v1.11.1-beta12
Running diagnostic tests:
[OK]      Moby booted
[OK]      driver.amd64-linux
[OK]      vmnetd
[OK]      osxfs
[OK]      db
[OK]      slirp
[OK]      menubar
[OK]      environment
[OK]      Docker
[OK]      VT-x