Skip navigation

Tag Archives: add-ons

Over a week ago, I collected the data I said I was going to look at last time. I finally had a chance to look at the data (startup times with and without add-ons for two profiles on the latest version of 3.6), and my hypothesis was not verified. That means it is back to the drawing board for me. The graphs are not at all interesting, so I am not going to post them. At this point, I think the goal is officially at risk. With the profiles we got, I am not even seeing slow startups with cold startup. It is hard to diagnose a problem you cannot reproduce, sadly.

Next Step

Next week I am going to sync up with limi and get some contact information from the people that sent these profiles to us. We are going to have to do some remote debugging to see why they see such slow startup times.

News on the Past

Paul is feverishly working on a solution to make session restore not kill us on startup. He even has some test builds which you can download and test, but these are experimental. You should make a copy of your profile as a backup when using this test build in case things go boom.

This week, I spent some time looking at some real life profiles that were sent into us by users seeing startup time in the minutes. The tests were ran just like I ran the test on my profile: all add-ons disabled. The results I got are both good and bad, but first the results!


The first shows the raw test run data (which isn’t terribly interesting). The second compares the reported startup time for each test. You will probably want to click to zoom in.


Like I said, the results are both good and bad. Good in that I now have a pretty good idea on why people have bad startup times. Bad in that we don’t have any way to quickly improve the issues that people are seeing. What I see from this data is that profiles in the wild, with add-ons disabled aren’t much slower than a clean profile. This seems to implicate add-ons being at least part of the problem (which we knew) or possibly all of the problem at this point (for the profiles tested). The good news is that the add-ons team is already working on solutions to this, and you should expect some blog posts from them about this soon.

Next Step

Next week I’m going to spend some time getting numbers with these profiles on the latest release of Firefox 3.6 with and without add-ons disabled to compare. This will pretty much confirm or deny my hypothesis of this week’s results.

News on the Past

In my last post, we looked at my profile with various pieces removed to try and figure out why startup might be slow for people. With those results, I identified two issues that would impact startup the most:

  1. Large cookies.sqlite
  2. Many tabs being restored

I also have good news about both of these issues! The cookies.sqlite issue is now fixed and will be a part of beta 4, and Paul has some good data about session restore and tabs (with more to come).