Linux /proc/sys/kernel: where are the files sysrq-sticky, sysrq-key, and sysrq-timer

linux-kernelmagic-sysrqproc

Documentation for Red Hat Enterprise Linux 3 (section 5.3.9.3) mentions these files in /proc/sys/kernel/:

  • sysrq
  • sysrq-key
  • sysrq-sticky
  • sysrq-timer

The documentation for RHEL 5 also mentions them.

Documentation for RHEL 6 does not mention any files except for sysrq.

If these files are mentioned in Ubuntu documentation, I can't find it. I also searched some of the Red Hat 5.x Release Notes, and I can't find it in there either.

The patch (against 2.4.11) to support these files (except sysrq-timer) was submitted to the kernel mailing list by Crutcher Dunnavant back in 2001; I don't know if it was ever officially accepted.

Checking current systems, I can't find the files (except for the sysrq file) on a RHEL 5.6 system nor on an Ubuntu Server Lucid Lynx 10.04.

What is the status of these files? Are they Red Hat-specific? Are they part of the kernel? Was the support removed? When?

Best Answer

Here you go. It's in the kernel mainline, selectable by config.

Basically, sysrq enables/disables the physical magic, the others are for programmed control. The doc's pretty straightforward.

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