Performance/Status Meetings/2007-July-11

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Participants

Infrastructure

• Generate reliable, relevant performance data (already underway as talos). Talos status update?

http://tinderbox.mozilla.org/showbuilds.cgi?tree=MozillaTest

• Areas where help is needed
• expand the scope of performance testing beyond Ts/Tp/TXUL/TDHMTL
• reduce noise in tests to ~1% (suggested by bz, not started)
• move perf tests to chrome, so we get more reliable results, and can test more than just content
• improve performance reporting and analyses:
  • Better reports for sheriffs to easily spot perf regressions
  • Tracking down specific performance issues
• stats change to track AUS usage by osversion.

• Priorities for infra:
  • Generate historical baselines
  • General profile data regularly on builds
  • Getting the perf numbers more stable
  • Developing the graph server to display time spent in each module

• New ideas
  • Question: How are we tracking perf bugs, specifically, and are we doing this the same way we are triaging security bugs? Can we do it the same way if not? (damon)

Agenda

Gecko: Perf discussion

• Perfathon update
  • vlad failing to provide data
  • vlad will do so by next wednesday, because even if I had started uploading useful data the upload probably wouldn't have finished by then (sorry!)

• pageload test rewrite (bug 387110)
  • since we have a chance at a clean break, we should look at how the composite scores are calculated
  • do we still want to ignore the biggest value when computing the mean and stddev? (there is caching and stuff that happens during the first time a page is loaded that ends up beneficially effecting subsequent page loads)
  • do we want to more cycle more intelligently?
    • e.g. do we want to keep cycling (up to some max) until the stddev drops below some number?
    • do we want to try to intelligently throw outliers out?

• update on timer resolution on windows from Rob Arnold.
• Talos results
  • What's it look like for 1.8 -> 1.9?

• Todo: verification of test results
  • Fonts, valid rendering, etc.
  • TODO: Stuart: verify that concerns about talos results are addressed

• probe update
  • vlad spoke with Sun guys
  • will work with them to integrate XP-probes and dtrace probes into (most likely) a new toplevel module
  • then will present to module owners and show demos
    • hopefully can convert per-module tracing schemes into probes
    • Sun guys would be happy to come out and do a presentation of dtrace-in-mozilla and give an idea of what can be done with dtrace itself and the scripts
  • dtrace should probably be on by default in our builds if dtrace is possible
    • not sure about OSX -- can we build with dtrace enabled and still run on 10.4?
  • xp probes should be off, but possibly on in our tinderbox/nightly builds
    • vlad to investigate perf impact

Previous weeks

• jrpof tinderbox

• synthetic tests (TODO)
  • put specific tests into talos framework
  • poach mochitest performance tests
  • individual reftest-like items

• need to get a bunch of people looking at profiles (TODO)
  • take up some of these meetings to sit down and look at profiles
  • timer-based profiling is better (vtune/jprof/oprofile/etc., not quantify)
  • TODO: vlad to generate profile for next week's meeting

• running without Fx chrome
  • new pageloader stuff can do this

• examining default theme for performance issues

• Tp vs. Tp2
  • new pageloader stuff avoids this problem
  • Tp2 was flawed in some ways -- one big one is that it loaded pages in an iframe, so initial paint delay was never coming into play, and we were potentially reflowing more thannecessary

Other Information

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