Results of the Graphics BugKill day on October 7, 2011

[Joe Drew]

Hi everyone,

Last Friday, we had the inaugural BugKill day, trying to clean up our
graphics bugs. During this day, all 10 graphics developers, and 2 lovely
people (Scott Johnson and Chris Lord) who aren't nominally part of
graphics, spent their whole day going through all of our open bugs,
trying to reproduce them and/or determine if they're still applicable.

We were able to close 308 bugs out of the 493 total we touched, which
translates to a pretty fantastic 63% close rate. (There were bugs we
didn't touch but did look at during this triage, so this percentage is a
maximum, but it's still quite good.)

To do this triage, I ran a Bugzilla query for all all open bugs in the
components GFX: Color Management, Graphics, Imagelib, Canvas 2D, and
WebGL. (This was about 2500 bugs.) To divide this among our
participants, I divided this long list by adding a regex query parameter
on Bug ID to choose bugs by last number. (For example, [1]$ for all bugs
ending in 1.)

Some of our observations:
* Having an open line to people (e.g. a Skype or Vidyo call) makes
triaging easier. There are lots of bugs that are essentially "do
such-and-such code cleanup", and it's difficult for someone who's
otherwise inexperienced in a piece of code to know if those bugs still
apply.
* Being able to shuffle bugs to others' queues would have been handy.
While it's useful to get fresh eyes on a bug, sometimes bugs will be
much more efficiently handled by a domain expert. More on this a little
later.
* There were several bugs with patches attached, but no review
requests, and nobody had touched them for 4+ years. Bitrot was
significant. It'd be worthwhile to do a quick query for patches in your
components that haven't got any review requests; you might be surprised.
* There were other bugs that we'd forgotten for no good reason, and
which had easy patches written while triaging. (!)
* Being bold is better than asking people. Resolve bugs as INCOMPLETE,
with the invitation to reopen, if you can't reproduce and need more
information from the reporter.

We still have >2100 bugs left open, and if our BugKill experience is any
indication, a majority of them aren't applicable anymore. In the mean
time, we're going to continue doing off-and-on bug killing on the list
of bugs we were assigned. And to add to that ad-hoc triage, we're going
to do another graphics BugKill on Friday, November 4, 2011: 3 weeks from
today.

However, we're going to make one important modification to our process:
we're going to allow people to send bugs to others' lists by (ab)using
the QA Contact field. That is, everyone's queries will have a list of
bugs selected by regex, and will also include every bug where the person
is the QA Contact. People can send bugs to others by changing QA
Contact, and once that person's triaged that bug, they'll reset the QA
Contact. I encourage others who are considering BugKill to do this from
the start.

Thanks for reading, and please feel free to ask me any questions.

joe