Subject: "systemctl suspend" on Linux is not reliable.
How long has it been since last time I used the the emergency sync SysRq?
Today traveled to Surakarta for a family event, I departed from Sragen. I suspended my laptop with "systemctl suspend" and put it into my backpack.
When I arrived in Surakarta, I opened my bag and felt my bag was so hot. It turned out that my laptop was on (not in a sleep state) and everything was spinning at 100% CPU (especially firefox and vscode).
I had a chance to check htop and tried to kill firefox with "pkill -9 firefox", but then the system froze.
When the GUI froze, I could still see my caps lock button was still working indicated by the caps lock LED on-off still responed to my input.
I tried to jump to tty4 and tried to login, but then soft lockup warnings appeared, everything froze. I could not login from tty4 neither.
I invoked an emergency sync procedure (Alt+SysRq+s) and forced my laptop off. Unfortunately, the SysRq to print backtrace was disabled. I am not sure how to debug this.
I hope this was not a kernel bug, just hope it was a random bit flip in my RAM caused by an extrme temperature that led to this scary incident.
Hopefully, my persistent filesystem will still be ok, not corrupted.
