xref: /kernel/linux/linux-6.6/Documentation/ABI/testing/sysfs-mce

What:		/sys/devices/system/machinecheck/machinecheckX/
Contact:	Andi Kleen <ak@linux.intel.com>
Date:		Feb, 2007
Description:
		(X = CPU number)

		Machine checks report internal hardware error conditions
		detected by the CPU. Uncorrected errors typically cause a
		machine check (often with panic), corrected ones cause a
		machine check log entry.

		For more details about the x86 machine check architecture
		see the Intel and AMD architecture manuals from their
		developer websites.

		For more details about the architecture
		see http://one.firstfloor.org/~andi/mce.pdf

		Each CPU has its own directory.

What:		/sys/devices/system/machinecheck/machinecheckX/bank<Y>
Contact:	Andi Kleen <ak@linux.intel.com>
Date:		Feb, 2007
Description:
		(Y bank number)

		64bit Hex bitmask enabling/disabling specific subevents for
		bank Y.

		When a bit in the bitmask is zero then the respective
		subevent will not be reported.

		By default all events are enabled.

		Note that BIOS maintain another mask to disable specific events
		per bank.  This is not visible here

What:		/sys/devices/system/machinecheck/machinecheckX/check_interval
Contact:	Andi Kleen <ak@linux.intel.com>
Date:		Feb, 2007
Description:
		The entries appear for each CPU, but they are truly shared
		between all CPUs.

		How often to poll for corrected machine check errors, in
		seconds (Note output is hexadecimal). Default 5 minutes.
		When the poller finds MCEs it triggers an exponential speedup
		(poll more often) on the polling interval.  When the poller
		stops finding MCEs, it triggers an exponential backoff
		(poll less often) on the polling interval. The check_interval
		variable is both the initial and maximum polling interval.
		0 means no polling for corrected machine check errors
		(but some corrected errors might be still reported
		in other ways)

What:		/sys/devices/system/machinecheck/machinecheckX/trigger
Contact:	Andi Kleen <ak@linux.intel.com>
Date:		Feb, 2007
Description:
		The entries appear for each CPU, but they are truly shared
		between all CPUs.

		Program to run when a machine check event is detected.
		This is an alternative to running mcelog regularly from cron
		and allows to detect events faster.

What:		/sys/devices/system/machinecheck/machinecheckX/monarch_timeout
Contact:	Andi Kleen <ak@linux.intel.com>
Date:		Feb, 2007
Description:
		How long to wait for the other CPUs to machine check too on a
		exception. 0 to disable waiting for other CPUs.

		Unit: us

What:		/sys/devices/system/machinecheck/machinecheckX/ignore_ce
Contact:	Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Date:		Jun 2009
Description:
		Disables polling and CMCI for corrected errors.
		All corrected events are not cleared and kept in bank MSRs.

What:		/sys/devices/system/machinecheck/machinecheckX/dont_log_ce
Contact:	Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Date:		Jun 2009
Description:
		Disables logging for corrected errors.
		All reported corrected errors will be cleared silently.

		This option will be useful if you never care about corrected
		errors.

What:		/sys/devices/system/machinecheck/machinecheckX/cmci_disabled
Contact:	Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Date:		Jun 2009
Description:
		Disables the CMCI feature.