This Week in Perf

Picking up from the last post, here’s what I’ve been up to for my part of the startup improvement project:


  • Landed bug 499123 – the effects on Ts as seen by Talos were mostly inconclusive (though were trending in the right direction!) and didn’t match what I had seen while testing locally.
  • Did some profiling for bugs 441355 and 496217. I posted some findings for 441355 and filed bug 512837 for a potential improvement discovered in the process. I haven’t been able to reproduce 496217 before the end of DelayedStartup() yet, though I suspect the default start page and its text field is probably what’s causing this to show up at times.

Next Steps

  • Didn’t have much time  to finish up bug 507073 due to the Firefox work week, but hope to do so next week.

This Week in Perf – Aug. 14th Edition

The Firefox team has recently started using small, well-scoped projects as a way to speed development and to better split up and coordinate tasks among many developers.  Since these projects are typically small and have well defined goals, we’re also using them train ourselves to communicate more effectively and more often (has it really been three years since I last blogged) about what our team is up to.

My project for the last couple weeks has been startup performance – mainly focusing on identifying and fixing areas where file IO is causing us pain.  Working with David, Dietrich, Drew, Vlad and Taras, we’ve found and have started working on some potential wins.

I didn’t have much time this week due to a cold and dealings with lawyers, but I started wrapping my head around the component loader in order to try having components packaged as a single JAR so that we can cut down on individual file reads during cold, non-fastload backed startups and stats in the warm case.

As far as what’s on tap for the next week I need to:

  • Write tests and finalize the patch for bug 507073.
  • Figure out the right direction for bug 507101.
  • Push to get outstanding reviews looked at. This has mostly been an issue of vacations and bandwidth and they’ll hopefully see some action within the next week.
  • File a bug with my findings for JAR’d components as I don’t really have the platform chops to properly tackle it 😉