When running a kernel with SysRq compiled in, this file controls the functions allowed to be invoked via the SysRq key. By default the file contains 1 which means that every possible SysRq request is allowed. Here is the list of all possible values:

• 0 - disable sysrq completely
• 1 - enable all functions of sysrq
• >1 - bitmask of allowed sysrq functions (see below for detailed function description):
  • 2 - enable control of console logging level
  • 4 - enable control of keyboard (SAK, unraw)
  • 8 - enable debugging dumps of processes etc.
  • 16 - enable sync command
  • 32 - enable remount read-only
  • 64 - enable signalling of processes (term, kill, oom-kill)
  • 128 - allow reboot/poweroff
  • 256 - allow nicing of all RT tasks