Red Hat Bugzilla – Bug 200444
echo c > /proc/sysrq-trigger does not cause a crash
Last modified: 2007-11-30 17:11:38 EST
Description of problem:
Version-Release number of selected component (if applicable):
How reproducible: always
Steps to Reproduce:
1.echo "1" > /proc/sys/kernel/sysrq
2.echo c > /proc/sysrq-trigger
3.You will get the message- SysRq : Trigger a crash dump -but the system doesn't
Actual results: no crash
Additional info: echo b and echo t do work.
I've done a little poking around with systemtap and have determined that
crash_kexec() is getting called, but machine_crash_shutdown() is never called.
So either this is evaluating true:
...or this is evaluating false:
Working on a debug patch to determine which it is...
The problem seems to be that kexec_crash_image is NULL. Looking at how and when
that gets initialized.
Check out the latest patch attached to bug 201618. :)
*** This bug has been marked as a duplicate of 201618 ***
Actually, this might be closer to a dupe of bug 198578...
kexec_crash_image gets set by starting the kdump service, which loads your kdump
kernel via kexec.