Performance/Snappy/2013-02-07

Snappy Feb 7, 2013 Minutes

Actions

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

Incoming

• Book your travel for Snappy work week and add to the wiki that Taras sent out - https://intranet.mozilla.org/Performance_Meet_Up_Paris
• bug 836488: Use read-ahead when loading plugin shared libraries
• bug 810454 Use fadvise() to speed up cookie db load
• Introduction to the Performance-Tests in WebKit http://blogs.adobe.com/webplatform/2013/01/24/introduction-to-the-performance-tests-in-webkit/

Projects

Startup & Shutdown

Results

• Bad stuff on timers
  • bug 822849 We no longer run GC/CC on a timer on shutdown
  • bug 833087 Have a patch in progress to stop progressively loading font on startup
• ~150 slow shutdown profiles. Several 20 second + shutdown
• Don't do any CC-related work before the first GC on startup (smaug)
• bug 827976: Create hidden windows lazily (startup improvement). Need to figure out why Talos numbers not showing expected improvement except for Android
• bug 833917 & bug 834003: Report on impact of disabling PGO on Telemetry data
• Looking into better grouping raw Telemetry data for more meaningful tracking of startup times

Todo

• Get a dump of raw Telemetry pings, check for late writes + "profile locked" measurements
• implement bug 838279 (aklotz)

Tab Strip (tab switch)

Results

• Tab animation smoothness telemetry got r+, should land soon (bug 828097).
• Tab animation performance suffers from 100% gradient cache misses (bug 837542), may also result in big memory spike during tab resize or animation (single cach item might be using a lot of memory on some cases - HD4000)
• Improving cache hits and using hacky 1px tiles - paints twice as fast (bug 835284)

Todo

• Improve gradients cache hits by changing cache key (bug 838758)
  • Windows with Intel GPU is specifically bad, bad when resizing window eats 5Mb/s (?) while resizing, doesn't use gradient cache
• Check if using rasterized tiles (bug 826422) and caching them (bug 835284) are still required (depends on bug 838758).
• possibly look into caching SVG rasters (for australis) (bug 764299).
• possibly look into newtab page perf (this seems the biggest bottleneck on a slow system)
• determine if we are not shutting down on tresize (bug 798219)

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

Results

• Bumping Plugin Hang UI Timeout from 5 seconds to 11 seconds
• bug 834127: Plugin Hang UI hangs mostly resolved in testing, but still happen occasionally when Windows DefWindowProc tries to synchronously send non-client mouse messages to IME window in hung Flash process. Going to attempt to hook those and suppress them during Hang UI

Todo

• bug 600370: Honza's latest version of DOMStorage

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

Results

• Landed, backed out, revised, waiting for review on bug 810146 (telemetry probes)
• bug 837212 (TelemetryTimestamps test conversion) r+, waiting for bug 810146

Todo

• SQLite performance in add-on manager (bug 729330)
• Blog about bug 729330 and bug 810149 (recursive directory scans)

Tools (profiler, eideticker, peptest, talos)

Results

• bug 788022 Profiler patches are ready to support Java profiling, waiting on breakpad to land them
• bug 837460 Cleopatra now supports displaying multi-threaded a profiles, a bit quirky but functional. Note c++ backend work for mult-thread support not completed, only the ui
  • Demo of java + MT profiles: http://people.mozilla.com/~bgirard/cleopatra/#report=2c44df22ccb94a5edf0645171ede974b134b0193
• Breakpad patches have been landing \o/. Tracked by dependant bugs of bug 779291.