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[0/2] watchdog/hpwdt: Disable Pretimeout/NMI in Crash Path

Message ID 1606097320-56762-1-git-send-email-jerry.hoemann@hpe.com (mailing list archive)
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Series watchdog/hpwdt: Disable Pretimeout/NMI in Crash Path | expand

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Jerry Hoemann Nov. 23, 2020, 2:08 a.m. UTC 
An intermittent issue was first noticed on RHEL 8.x during kdump.
When the dump completed and the system was in the process of resetting
an NMI would get generated as a result of an IO error.

For a discussion of the underlying cause and attempt to fix see:
	https://lkml.org/lkml/2019/12/25/159

The kernel's handling of the NMI generated an intermittent
secondary NMI that would hang the system.

As systemd enables WDT during shutdown, the WDT should have broken
the system out of the hang, but hpwdt_pretimeout stops the WDT
in order to allow the collection of a kdump.  But as we are
already in the crash kernel when the NMI is received, stopping 
the WDT is not necessary.

Jerry Hoemann (2):
  watchdog/hpwdt: Disable NMI in Crash Kernel
  watchdog/hpwdt: Reflect changes

 drivers/watchdog/hpwdt.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)