Performance/Snappy/2013-03-07

Snappy Mar 7, 2013 Minutes

Actions

• [DONE] benwa to send lmandel list on slow shutdown add-ons for follow-up with add-on team
• Irving to test what happens when an add-on switches from unpacked to packed (look at ABP specifically)
• Taras: talk about PICL perf review

Incoming

• A closer look at the performance of Google Chrome http://aptiverse.com/blog/closer_look_at_chrome/ looks at caching, coding strategy, and process isolation
• bug 844947 - Choppy scrolling on Firefox Partners website (and many others) on Mac Retina display
• telemetry-reboot (on server) https://etherpad.mozilla.org/telemetry-reboot
• https://sites.google.com/a/webpagetest.org/docs/using-webpagetest/metrics/speed-index chrome has time-to-stable-content now (Taras file bug# + find owner)
• <--idle-daily skew
• Change telemetry histogram display default to 'saved-session': METRICS-1408

Projects

Startup & Shutdown

Results

• bug 845907: Abstracted readahead functions have landed. As a result:
• bug 810454: A/B test for cookie readahead landed in m-c this morning
• bug 810151: Ordered jar file readahead - 60% drop in omni.ja startup read time on Windows test. Landed in inbound yesterday, was backed out due to suspected xpcshell orange. Will resolve ASAP.

Tab Strip (tab switch)

Results

• bug 829952 (slow touchpad scroll): testcase to measure cross-browser + blogged.
• landed bug 842967 (refresh driver can retarget a timestamp).
• bug 590422 (Remove timer filter): landed, backed out: lots of backfire from timing-related regressions:
  • bug 845943 (fix talos tscroll) - close to finish.
  • bug 749894 (Mochitest performance.now() orange) -> research -> 10% failures due to disabled high-res timer on XP on 25% of the cases -> 1. test could be improved. 2. regression of bug 822490 (simplify windows timestamp) -> elevated bug 836869 (improve high-res timer detection hueristics - Honza Bambas). Still not decided if low-res timer should pass or fail this test (right now it sometimes fail).
• (update - mconley): Australis on par with default theme, they moved on to refinements, mconley will occasionally check perf to make sure no regressions.
• (update - ttaubert) newtab performance: XUL is expensive, consider CSS3.

Todo

• keep killing regressions of bug 590422.
• bug 829952 (slow touchpad scroll): talk to masayuki, he has ideas for improvements, see where it stands.

Temporary and Severe Browser Hangs (front-end, downloads, chromehang fixes, scrolling, prefs, slow sql)

Results

• Final patches for bug 566746 (async form history) posted (including test fixes)
• bug 820834 landed (about:home storage refactor)

Todo

• Investigate performance of LiveMargin extension distributed by Mozilla China http://firefox.com.cn/download/#other-download
• lmandel to follow up on priority of emerging markets
• In progress: bug 838577 (cut Session Restore collection in chunks).
• land bug 789348 (about:home storage migration)

Add-on and Web page introduced slowness (add-on manager start-up)

Results

• Found bug 844958, bug 845921
• Filed bug 846921 for detailed add-on telemetry, got redirected into FHR
• Discussions with felipe et. al. about next steps for add-on manager improvement

Todo

• File bugs and finalize design for converting AddonManager.jsm and XPIProvider.jsm from sqlite to JSON
• vladan to follow up with jorge about slow add-ons

Page Load (cache, dns)

Results

• Putting up full page load tests to test more than networking layer
• WIP patches for cache, e-mail try build to taras and vladan

Tools (profiler, eideticker, peptest, talos)

Results

• SymbolicationServer & Profiler extension to support symbolicating Thunderbird & other apps
• bug 837724: comparison of Telemetry histograms during a Talos run from a PGO MSVC2010 build versus a non PGO MSVC2012 build
• Improving security of the profiler add-on for AMO. Parameters are chrome controlled but are passed directly to the shell. I have patches to escape them correctly.
• Worked with intel to support MSR/power profiling.
• Discussed with Vlad the profiling needs for Gaming. Planning to focus on Multi-thread/Multi-process support, runtime overhead, JS frame sizes, and delimiting frames and transaction in frames.
• JS Team is looking into adding profiling support to Baseline & asm.js

Todo

• Pending feedback: bug 832664 (Efficient, async JSON serialize/deserialize)
• Mentoring: bug 848278 (Measuring performance of OS.File operations)
• bug 788495: Reproducing crash in js::SPSProfiler::JMChunkInfo::convert, fix in bug 832812 making it hard although I still get the odd crash once per day