Mobile/StartupOptimization

Issues

Trunk Firefox takes ~15s to show the main window on the N800. With a simpler chrome it reduces to about 8s. The Maemo browser on the same hardware takes ~3s, and Safari (iPod Touch) takes less than a second.

Goals

Initial goal: Reduce startup time as perceived by the user to less than 3s.

Task list

Here are some potential optimizations:

• Startup bugs

[1] [2]

• Improve fastload performance
  • Filed bug 412796 [3]
• Optimize mobile chrome
  • UI design
  • XUL Optimizations
• Function re-ordering
  • Streamline memory access by placing all code & data needed for start-up in contiguous sections at the start of the binary.
• Optimize memory allocation
  • Significant time during startup is in memory allocations. Need link to ongoing work.
• Optimize startup hotspots
  • Bug 406810 [4]
• Preload Mozilla libraries
  • Preload all libraries during startup; launching Firefox only loads the XUL application.
• Preload Mozilla application
  • Launch Mozilla during device startup and keep in background (no visible window). Launching Firefox will only open a new window.
• Identify & disable unnecessary work during startup (for mobile)
  • Bug 421561 [5]

• removing comments from all evaluated source files (js, css, xul). Less to read in.
  • Bug 463066 [6]

• look at what system libraries are being opened on start. strace shows we looking around for system version of nspr, nss, ect? Maybe we can help the dso loader.
  • Bug needed.

• look at what locales are being loaded in. strace shows we are loading in locales that are not needed at startup.
  • Bug needed

• merge all XPT files.
  • Bug 469873 [7]

• Can JS files be precomputed/precompiled?
  • bug needed.

• Reduce chrome files. For a XUL runner app, we do not pageloader for example. There are others. This should be included in make package.
  • bug needed.

• Reduce js files. there are probaby some js completes that we do not need. (default command line handling, for example).
  • Bug 468607 [8]

• Is sqllite doing a bunch of unneeded F_SETLK64s (fcntl64)? Maybe we do not have to be so overly protective of other writers?
  • bug needed

• Does XR need the hiddenWindow? starting this takes times.
  • bug needed

Bugs