why certain apps can freeze the entire OS? If processes alternate each other by scheduler, then why computer freezes? Why it happens? How can a program/app have this “power” to do it? What are the most common reasons? Is there a way to unfreeze it? If I wait a lot, will it eventually unfreeze?

Question

You can answer in technical ways (even though the sub says the opposite) if you want. I should understand it.

In: 3

Answer 1

There’s a few things that can be happening under the covers when this happens. Most programs are multithreaded, and it can be that it is executing so many things on so many threads that the CPUs all get pegged and there simply aren’t any CPU cycles available to give to the OS to let you fix the problem (looking at you Chrome 🙄). Another common cause is antivirus programs. Most antivirus software is setup to scan the file system when new files are written to make sure there isn’t anything nefarious being written. Most antivirus software that does this will have options on which directories to check, but sometimes you can have a situation where the software is writing out a large file, and the antivirus keeps detecting changes, so it keeps scanning the file as well, and then your program and the antivirus are competing for CPU and memory and disk I/O threads. And with Windows, the OS itself is a pretty big resource hog in terms of CPU and memory. So then you run into situations when you have another CPU and memory intensive program running and Windows and that program will be fighting and in some cases deadlocking over those resources. One final example I can mention, as I’ve seen this on an older windows computer I still use from time to time… similar to the antivirus is firewall software. So the firewall that I’m running there will randomly forget programs that are allowed to connect to the internet and will ask again if they can, or if it should block them. So sometimes when I wake it up from hibernating, I’ll have Chrome trying to reconnect all 20 tabs I have open, and using up all the CPU on the laptop trying to do that, meanwhile my firewall is trying to show a pop up asking if it’s ok to let Chrome connect to the internet, but it can’t because it has no CPU. When that happens, I basically need to just reboot the laptop because it’s stuck and won’t be able to get out of that situation.