Performance/MemShrink/Meetings/2011-07-05

Announcements

Bug list - 16 bugs

Most P1 bugs in good shape :)
- Bug 592833 had been waiting for today's aurora merge
- Bug 414946 (jemalloc-on-mac) had been waiting for today's aurora merge, and will likely land today!
Bug 637931 demoted to P2: we agree it's "long term"
Bug 651695 demoted to P2

Bug list - 14 bugs

https://bugzilla.mozilla.org/show_bug.cgi?id=668809 - we decided this is a P1 metabug
- We considered splitting out "use diffbloatdump after doing some normal browsing" into a separate information-gathering bug
https://bugzilla.mozilla.org/show_bug.cgi?id=668871 - turned out to be multiple bugs, one involving firebug and one with some kind of timing issue.
- Let's file a separate bug for firebug (which might turn out to be a dup of bug 669096)
- Do compartments map 1:1 with anything that appears in about:bloat? (Fuzzing uses about:bloat)
  - Should map 1:1 xpc::CompartmentPrivate ... which isn't listed in about:bloat
https://bugzilla.mozilla.org/show_bug.cgi?id=669120 - controversial!
- heap-minimize is a big hammer. clears user-visible things like bfcache. (but perhaps we could exclude bfcache for the most-recently-active tab or something like that)
- maybe only if firefox is minimized and remains minimized for over a minute

bug list - 44 bugs

https://wiki.mozilla.org/QA/Mozmill_Test_Automation/Endurance_Tests
http://mozmill-crowd.brasstacks.mozilla.com/#/endurance/reports
Currently consists of 6 tests, each of which have at least two checkpoints at which they measure memory use (explicit and resident for Firefox 6+, mapped and allocated for Firefox 4-5)
This framework can also be used for ad-hoc tests (such as tests that load a public web site over and over again)
We don't have a great idea of which browser features (or which web sites) are important to test in this manner
Intending to ramp up tests in Q3, and align with Memshrink and Telemetry
Can run tests with additional addons installed
Intending on comparing average results between builds from same hardware

Jesse is playing with a DOM fuzzer mode that detects more types of leaks. (After doing random stuff: navigate to blank, GC+CC+MP, count windows & documents using about:bloat.)
Found 4 bugs just looking for extra documents & windows https://bugzilla.mozilla.org/buglist.cgi?quicksearch=669096%2C669105%2C669110%2C669240
What should I have the fuzzer look for next?
- nsGenericElement?
  - nsGenericHTMLElement would have the advantage of having less chrome churn
- Everything that appears in about:bloat?
  - Likely to be noisy
- Everything that appears in about:memory?
  - Could enumerate the reporters, like about:memory does
  - Some of the things are computed by about memory js, which doesn't provide an API of its own