Hector Martin

oh boy I ran into my FAVOURITE Linux “feature” again, uninterruptible sleep, reproducibly, while at work

“no but what is it actually” if your process does certain kinds of system calls, including certain I/O system calls, then it is impossible to kill the process while it is waiting for it to return. yes, not even SIGKILL. yes, the only fix is a hard reboot. yes. I know. I knowwwwww

I hate uninterruptible sleep so fucking much, fuck backwards compatibility, every system call should be able to return EINTR or, hell, pretend the operation failed in some other way or whatever, just let me kill misbehaving processes ;_________;

That's not a backwards compat thing though, it's a kernel bug. The point of uninterruptible sleep is that if your process is running *in kernel mode* then you can't kill it except where allowed, because that would kill *kernel code* at a random point and that's Bad™.

So in theory in any non-pathological system state, the kernel shouldn't be leaving a process in uninterruptible sleep for any significant length of time. If it does, either you have a problem or it's a kernel bug or misfeature.