All along the dwatch tower: A DTrace tool for the masses

Devin Teske <>

I would like to present a new utility called dwatch that I added to FreeBSD 12.0-CURRENT.

Using dwatch, in this talk you will learn how to:

  • Watch processes entering system CPU scheduler
  • Print arguments being passed to functions
  • Easily watch multiple probes simultaneously
  • Globally watch all function traversal from every process/thread
  • Filter output by user or group, including the ability to use regex
  • Watch jail activity
  • Use patterns or regular expressions to match on executable name(s), pid, etc.
  • Look for a particular path being created, removed, accessed, etc.
  • Watch interprocess communication signaling
  • Log network data events
  • Schedule timed samplings for events of interest
  • Dump process trees for processes triggering a probe
  • Watch child processes
  • Show commands being executed in realtime
  • Write modules to centralize logic into easy-to-access profiles
  • Share modules with each other and help your community
  • More…

With dwatch, using DTrace has never been so fun and painless.

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