How to use the SysRq key

I can confirm it works on my end (Fedora 35) with Alt + PrtScr (SysRq) + command key.

  • Function lock off:
    When F11 functions as PrtScr (which is also SysRq) there is no need to hold Fn:
    Alt + F11 + command key (e.g. M)

  • Function lock on:
    When F11 functions as F11, hold Fn to convert it into PrtScr/SysRq:
    Alt + Fn + F11 + command key (e.g. M)

Press the key combo, and it should work. On Fedora 35, if the command is supposed to output to the console, it should show up in the journal. Follow the journal with journalctl -f. If the combo is disabled:

sysrq: This sysrq operation is disabled.

Reminder that any value >1 is a bitmask, so 16 only turns on enable sync command and changing it to 256 only turns on allow nicing of all RT tasks. If you want to selectively enable e.g. both, then set it as 272 (16 + 256). 0 = everything disabled and 1 = everything enabled.

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