Firefox sloooooooooow
Out of context: Reply #27
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- ukit0
Did you guys see the article posted earlier?
"That forum thread revealed what the true cause was of this disk thrashing and delay at startup. I have to warn you though. If you're a developer, your software engineering fire will die a little when you read the true cause and from then on you will have to fight off thoughts of giving up development altogether and apply for a job in marketing or HR. So what was it, what's the cause of this slowness? It's NSS. What? The Network Security System. It turns out that NSS needs to do all kinds of encryption and other security related tasks (which seems kind of logical), and for that it needs random numbers. Sounds reasonable, right? Well, it kind of does.
True random numbers are hard to produce, because in a computer system, nothing is really random, it all is a result of some action which was a result of some action etc. etc. The clever boys and girls of the NSS team had to crack this problem: how to get 'true' random numbers which are as random as possible? Instead of using the randomization functionality of the underlying operating system (which has this feature build-in as every TCP stack for example needs it), they did what Mozilla in general always does: they re-invented the wheel. Nothing against re-inventing stuff, don't get me wrong, not every wheel is as equal as the other one, and you can never have enough good, re-invented, shiny wheels. Though, the downside of re-inventing wheels is that along the way you can't make mistakes, it has to be better than the previous invented wheels. No-one wants to use your square new wheel for example.
To solve the problem of the randomization, the NSS team came up with something clever, something so great, that no-one else had ever thought of that before: they decided to read the files in all possible temp folders on disk with multiple threads so these files can be used as seeds for the randomization. Brilliant. Temp folders! Why hasn't anyone else thought of using a disk-based resource for random number generation! I mean, these folders change every couple of milliseconds, have immediate access, no latency to read their contents and are never filled to the brim with useless cruft!
That is, if you're on the NSS team. In the outside world, things are a tad different. You see, Firefox v3.5 reads the Internet Explorer Cache and the central Windows temp folder in your user profile, through its NSS subsystem. Not only is it, in my humble opinion, not done to read another application's caches or temp folders, it's also amazingly ignorant towards the real bottlenecks of our modern computers: hard-drives. If you're using a virus-scanner which is set to paranoia mode, this whole temp folder traversal by NSS will be even slower because every file accessed will be scanned by the virus scanner. Over and over and over again..."
F*cking nerds...