Snappy Feb 21, 2013 Mintues

Actions

• benwa to send lmandel list on slow shutdown add-ons for follow-up with add-on team

Incoming

• Off-main-thread painting discussion on dev-platform https://groups.google.com/forum/?fromgroups=#!topic/mozilla.dev.platform/Ah-lgbvDRHE
• bug 842777 - preload webappsstore.sqlite - This is going to be trivial after changes in {{bug|810454} go in. Q: Do we want to just automatically readahead when db file is < size N? (aklotz)
• bug 840651 - Some telemetry clients are sending many idle-daily pings per day

Projects

Startup & Shutdown

Results

• bug 810454 (cookie db readahead): Submitting patches for review today. Includes generic preload for shared libs and other files, integration into storage service so that other DBs can easily leverage readahead
• bug 827976: Create the Firefox hidden window lazily on non-Mac platforms
• Firefox 19 start-up press http://blog.laptopmag.com/mozilla-firefox-19-hands-on-speedier-startup-built-in-pdf-viewer

Tab Strip (tab switch)

Results

• bug 828097 (Tab animation smoothness telemetry): landed, data collected - Good when opening a blank page, not so good when newtab preview is enabled (with or without prelod) - especially on slow systems. Telemetry: http://goo.gl/LHjTZ
• bug 838758 (modify gradients cache key) - landed. Eleminates big mem spike on some systems (HD4000) - bug 837542, D2D speedup 20-25% of tab animation. Possibly small (7%) regression for non D2D - need to retest.
• Working with fx-team (MattN, mconley) on Australis performance (mostly helping with test tools, methodology). They collect good data and take the subject seriously. Tracked at bug 837885. Benchmarks: http://goo.gl/TOXLe , now at about 15-20% regression from default theme on slow systems (down from 100%+) mostly due to SVG > PNG.
• fx-team can use PNGs instead of SVG - reduces the acuteness of SVG raster cache.
• Timer interval irregularities hurt smoothness (bug 842967 - may retarget the same timestamp - landed, bug 590422 - remove timer compensation/smoother - patch, waiting for backfire). vlad helps.

Todo

• newtab preview perf bisection (with ttaubert): disable thumbnails resize, borders, overlays, shadows. Take measurements, decide what to tackle.
• Followup timer interval irregularities.
• Tab animation: Understand where 60%+ of frame interval go outside of layout-flush/paint.

Content (GC, CC, DOM storage, flash hang, DOM event/task scheduling)

Results

• bug 842852: Checkpoing WAL log more frequently + prevent latch-up of reader/writer thread. Need to measure perf impact

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

Results

• Paolo: landed skeleton for a new download API. Iterating on features and will eventually port over callers (bug 825588)
• Marco: will be landing bug 820834 soon, which paves the way for removing localStorage use from about:home (bug 789348)

Todo

• Tim to file bug for near-term tab thumbnail capturing policy improvements
• Drew to continue investigating background tab thumbnailing service
• Neil nearing final stages of patch for bug 566746 (async form history)

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

Results

• Telemetry for unpacked add-ons landed (bug 810146), but I suspect the results are skewed by changes detected because of updates (particularly for Nightly); filed bug 841028 to track changes to build ID in telemetry

Todo

• We're seeing very high number of Telemetry reports of unpacked addons getting updated without any changes to their install.rdf. If you see "addonManager: {"modifiedExceptInstallRdf": n > 0, ...}" in your about:telemetry's "Simple Measurements" section after starting Firefox, please contact Irving or Vlad.
• Design more detailed add-on telemetry format to allow per-addon information such as bootstrap time, files changed off line, anything else?
• Do addons stay unpacked even if they get updated to no longer requiring being unpacked? Seems to be the case with ABP(need confirmation)
• Irving to test what happens when an add-on switches from unpacked to packed (look at ABP specifically)
• Johnath seems to be pushing to restart tracking addon perf. Should revisit tracking startup, memory usage, shutdown of addons

Tools (profiler, eideticker, peptest, talos)

Results

• New profiler extension awaiting AMO review
• Progress on Multi-thread, Multi-process process, Java Dalvik, breakpad unwinding. All of these features can be tried by applying patches locally.
• Keeping an eye on shutdown performance reporter. Right now most of the issues are CrossCompartmentWrapper which Add-on sdk has landed a fix
• Julian's ETA is 1 weeks
• Rafael is adding late-write reports to the Metrics' reporting script

Todo

• bug 843367: Add Thunderbird symbols to Snappy Symbolication Server