It always works for me, including on SBCs over TTL serial port. Always. Never had a situation where invoking the OOM killer by sysrq didn't solve the swap storm

It always works for me, including on SBCs over TTL serial port. Always. Never had a situation where invoking the OOM killer by sysrq didn't solve the swap storm. On your system it probably doesn't work at all, not even when idle. It can only be 3 reasons: - Your kernel doesn't have it. You probably have a generic kernel provided by the package manager without this feature enabled. I can't really help you here. I always build my own kernel from source (+ patches). - Something hijacks your keyboard input. If you have a console already opened and logged in as root, you can "echo f > /proc/sysrq-trigger". Else, you can try setting up a permanent serial console and send the command from another computer. CTRL+2 then the command letter (f). The magic sysrq key over serial console is a separate kernel option that needs to be enabled. - You're doing it wrong. On laptop keyboards, keyboards less than 104/105 keys, sysrq is one of the first keys to be removed. Getting it pressed with Fn combinations... Good luck with that!