I'm a programmer by trade with twenty years of experience, having first used Linux in 2004 (iirc), and I thought I knew the game pretty well. There are CPU-bound tasks, memory-bound tasks, network-bound tasks, and disk-bound tasks. I'm doing async programming and it's working fine, offloading i/o to the kernel while my app is doing cpu stuff. Except, I'm now using a laptop with 8 GB of memory and Linux Mint-Cinammon on HDD as my main machine, and somehow shit is constantly in the swap and waits for the disk. Right now I'm moving a Windows partition, I have quit everything except four Firefox tabs, Emacs, and Double Commander — and I still think I might kill myself before the ordeal is over. The entire system is completely and totally fucked. Barely anything moves, nothing responds in any kind of a timely fashion. Emacs freezes when typing, with two open buffers. Audio playback stutters. VPN is nonresponsive. I closed all the hundreds of buffers in Emacs, I set the priority and io priority of Gparted to the minimum, and the other apps to the max. I set swappiness to zero, and turned off the swap altogether with swapoff. All of this barely helps. I'm drunk right now, and still this affair bugs me beyond measure. I could maybe deal with this as a one-time thing if swapping and disk i/o weren't incapacitating the system every day.

Is Linux kernel so ridiculously single-threaded that any i/o cripples the entire thing? Or is something tuned horribly wrong in Mint by default? Can I unfuck this somehow? I live close to a river, I can't take this much temptation.