Comments on: Startup Time in the Wild

By: Startup Time in the Wild Take Two : Shawn Wilsher

Startup Time in the Wild Take Two : Shawn Wilsher — Fri, 13 Aug 2010 19:20:51 +0000

[...] Comments Shawn Wilsher on Startup Time in the Wildpd on Startup Time in the WildM. Caywood on Startup Time in the WildPaul OShannessy on Startup Time [...]

By: Shawn Wilsher

Shawn Wilsher — Thu, 12 Aug 2010 17:31:33 +0000

Where does it say that I’m working to improve the startup time of a “clean profile”?

By: pd

pd — Thu, 12 Aug 2010 17:28:57 +0000

Unfortunately the goals, or more specifically the non-goals are probably the most accurate ‘metric’ for what users can expect from all this start up work: not very much!

How many users run a ‘clean profile’ ?
How many users run without any extensions?

If all the previous work on start up time – the Planet Mozilla evidence of which has vanished – was merely to improve clean start up and you are only getting to this dirty start up work now, with a margin of 20%, should users really expect a real-world faster start up from Firefox 4?

I appreciate that test conditions have to be consistent and scientific but really, to test start up performance without any add-ons is far from realistic surely?

When are we going to get a Firefox that actually does start up within 5 seconds in real-world conditions, Firefox 8?

By: M. Caywood

M. Caywood — Tue, 27 Jul 2010 22:15:28 +0000

Thanks for the quick response, Shawn; filed as Bug 582396 (https://bugzilla.mozilla.org/show_bug.cgi?id=582396)

By: Paul OShannessy

Paul OShannessy — Tue, 27 Jul 2010 17:43:12 +0000

@AndersH – That won’t have any effect on startup time. We only ever read sessionstore.js. The others are probably there due to an addon. They might also be there due to timing of writes, which could cause your OS to add -N to the filename. They are all safe to delete (unless they are used by an extension, but if you don’t know why they’re there, it’s probably safe).

By: Shawn Wilsher

Shawn Wilsher — Tue, 27 Jul 2010 17:35:19 +0000

M. Caywood: It would likely be best for you to file a bug on this, and we'll take it there. Something is certainly not right here, and we should get to the bottom of it.

By: AndersH

AndersH — Tue, 27 Jul 2010 13:40:25 +0000

A few days ago, I looked in my profile-folder and found 34 files called sessionstore-1.js … sessionstore-34.js. They are probably just old sessionstore.js-files, but would these have any effect on startup time?

By: M. Caywood

M. Caywood — Tue, 27 Jul 2010 04:41:19 +0000

Hi Shawn, my startup time has massively regressed between Firefox 3.6.8 and 4beta1 — some delayed startup event in Places is taking about 30 seconds and freezing the browser. It seems to happen on a timer after tabs open and windows raised, or is triggered if I focus the location bar.

It started misbehaving when I imported all my tagged delicious bookmarks so I could switch to using Firefox sync instead. DB files are large but not huge: Places.sqlite = 40 MB, formhistory.sqlite 1.5 MB. I can supply my places data (securely) if necessary.

I couldn’t find a bug for this for Beta 2 or in a search of Bugzilla; are you aware of any major Places startup regressions?

By: Shawn Wilsher

Shawn Wilsher — Tue, 27 Jul 2010 00:35:14 +0000

I cannot possibly conclude that, nor did I say that that was my conclusion. We need to start somewhere, and this is certainly it. This week I’m going to be looking at some profiles that were given to us by users and see if a) I can reproduce their slow startup and b) I can get useful data from the profiles.

I also see people frequently stating that they have long startup time and then also brag about the tens or hundreds of tabs they have open on a day-to-day basis. The session restore performance hit scales linearly with the number of tabs it has open. I only had eight in this test.

And of course, I don’t expect there to be a magic bullet that will solve the startup problem. It is very likely a complicated problem without a simple solution.

By: Michael Lefevre

Michael Lefevre — Mon, 26 Jul 2010 22:43:52 +0000

I understand about the extensions (I read the wiki page already). But I doubt those reports of long startup times are coming from people who have a startup time of 620ms.

Not that I have any better ideas of how to test, and the conclusions of looking at session restore and places seem reasonable. But if someone has a startup taking 20 seconds with no extensions, how can you conclude from your test that session restore is a similar chunk of their startup time, and that your 20% gain will translate to a 20% gain for them, rather than a 100ms gain (which would be <1% for them)?