Firefox Startup Performance – January 15Posted: January 16, 2010
Happy 2010 everyone!
Top Startup Bugs
|Estimated win||Bug #||Summary||Owner||Status||Notes|
|>10%||512584||Super fast paths for Components.classes and Components.interfaces||Taras Glek||in progress||Taras is traveling, says he’ll close it out when he returns.|
|>10%||525013||Investigate a more static build configuration of Firefox||Joel Reymont||in progress||Lots of progress! Joel has a patch for Mac and Linux working on the tryserver, and numbers to confirm a partial static build gets ~8% improvement on Mac, with no compat problems. Zach added a bunch of number crunching to validate Joel’s numbers. On the Windows front, Taras has a patch in progress now.|
|up to 25%||514083||Per-file HFS+ compression on Mac OSX 10.6||Joel Reymont||in progress||Conclusion is that we need to make this happen via the installer, as well as the updater, since modifying files results in decompression. Need to find an owner for this still.|
|TBD||520309||Startup cache: replacement for fastload cache||Ben Hsieh||in progress||Ben is looking into a perf regression that arose after some major changes.|
|TBD||503483||Turn on –enable-faststart for Firefox by default||Dietrich||needs testing||No update, need to test still. Maybe just push on Windows here.|
|TBD||513149||Speed up CSS parsing by using a machine generated lexer||Zack Weinberg||Zack’s blocked on other work||No update.Taras says about 6% of startup spent parsing CSS.|
Other activity this week:
- I updated Mark’s patch in bug 507012 to trunk and ran it on Windows. Here is the ranked log and the stack view. From perusing this data, I filed bug 539997, bug 539991, bug 539869 and bug 539870.
- I’ve been working on bug 506471, to move FUEL out of the startup path, and also making a bunch of minor improvements and cleanup in that code.
- While I was gone, Rob Strong put up a great post about what JS components are in the startup path and how much time they take up.
Projects in a holding pattern:
- More investigation into Hunspell changes in bug 468799, possibly incorporating some changes Chrome made.
- JARification: David abandoned moving JS modules into a JAR file, since those files are fastloaded. However, since we want things like post-extension-install restarts to be fast, and those cause fastload cache invalidation, we might want to do things like this anyways. I filed a bug for the same treatment for components. These are lower priority, since they’re not the normal startup case. Follow along with all JAR-ification via the tracker bug.
- Startup Timeline: No updates, still not landed. Add [ft] in the whiteboard of your bug w/ the function names you want timed and David will generate it and update the bug.
- Static Analysis: No progress on bug 506128. David needs to file a bug with the final log of named-yet-uncalled functions.
- Dirty Profile Testing: No progress. We have a list of test scenarios, still need to file bugs for each, generate Talos config patches and profile data, and then move it into Rel-Eng territory. Also, need to get a separate Tinderbox tree, since it’s going to cause a bazillion new columns.
- Joel Reymont noted in bug 513076 that there are serious drawbacks to getting our libraries in the dyld shared cache on Mac, so has deprioritized that work.