(In reply to Laurentiu Nicola from comment #5)
Is this really a good idea? Warming a cache at startup seems to save 5 seconds or so of IO and makes Firefox appear to start faster.
But on the other hand, that's some 5 seconds of IO that's taken away from the rest of the system. Especially on low-end computers, the first couple of minutes after startup are especially painful, and implementing this for Firefox will only contribute to that.
It reminds me of the "quick starters" that larger apps like OpenOffice used to have (although those remained resident).
Yeah, outside of this bug I've had a few conversations about that, and that's a large part of what I'm talking about when I say "we need to figure out all the implications of doing this." For one, I want to measure the impact that this has on the time until the machine is started up and basically usable. I haven't sorted out a good way to measure this yet - one idea might be to have the machine open, say, MS Word right after startup and measure the time taken from power button pressed to a Word window open. If it doesn't impact that measure then I think it's likely we could put the question to bed.
However if it does impact that measure then we need to have subtler conversations, and I think it will depend on exactly how much impact we're having on overall startup vs how much benefit we see for Firefox startup. If Firefox is always the first application a user opens, then it still makes sense to run this, since in the worst case it still consolidates the time that the user is waiting. I.e., they would wait 2 minutes for their machine to start up and 5 seconds for Firefox to start up, rather than 1 minute and 55 seconds for their machine to start up and 10 seconds for Firefox to start up. I would argue that it feels more frustrating to have two long waits than one longer wait and one short wait, if that makes sense.