bf0cf32191
Changeset 62fdac5913 ("x86, mce: Add boot options for corrected errors")
added three more MCE files that are also exposed currently via
sysfs.
Document them.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/f9c13aff3f5a2cae0d4495eccd17f431f3a4c55a.1632994837.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
130 lines
4.4 KiB
Plaintext
130 lines
4.4 KiB
Plaintext
What: /sys/devices/system/machinecheck/machinecheckX/
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Contact: Andi Kleen <ak@linux.intel.com>
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Date: Feb, 2007
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Description:
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(X = CPU number)
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Machine checks report internal hardware error conditions
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detected by the CPU. Uncorrected errors typically cause a
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machine check (often with panic), corrected ones cause a
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machine check log entry.
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For more details about the x86 machine check architecture
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see the Intel and AMD architecture manuals from their
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developer websites.
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For more details about the architecture
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see http://one.firstfloor.org/~andi/mce.pdf
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Each CPU has its own directory.
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What: /sys/devices/system/machinecheck/machinecheckX/bank<Y>
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Contact: Andi Kleen <ak@linux.intel.com>
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Date: Feb, 2007
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Description:
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(Y bank number)
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64bit Hex bitmask enabling/disabling specific subevents for
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bank Y.
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When a bit in the bitmask is zero then the respective
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subevent will not be reported.
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By default all events are enabled.
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Note that BIOS maintain another mask to disable specific events
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per bank. This is not visible here
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What: /sys/devices/system/machinecheck/machinecheckX/check_interval
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Contact: Andi Kleen <ak@linux.intel.com>
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Date: Feb, 2007
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Description:
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The entries appear for each CPU, but they are truly shared
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between all CPUs.
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How often to poll for corrected machine check errors, in
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seconds (Note output is hexadecimal). Default 5 minutes.
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When the poller finds MCEs it triggers an exponential speedup
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(poll more often) on the polling interval. When the poller
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stops finding MCEs, it triggers an exponential backoff
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(poll less often) on the polling interval. The check_interval
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variable is both the initial and maximum polling interval.
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0 means no polling for corrected machine check errors
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(but some corrected errors might be still reported
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in other ways)
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What: /sys/devices/system/machinecheck/machinecheckX/tolerant
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Contact: Andi Kleen <ak@linux.intel.com>
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Date: Feb, 2007
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Description:
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The entries appear for each CPU, but they are truly shared
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between all CPUs.
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Tolerance level. When a machine check exception occurs for a
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non corrected machine check the kernel can take different
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actions.
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Since machine check exceptions can happen any time it is
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sometimes risky for the kernel to kill a process because it
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defies normal kernel locking rules. The tolerance level
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configures how hard the kernel tries to recover even at some
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risk of deadlock. Higher tolerant values trade potentially
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better uptime with the risk of a crash or even corruption
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(for tolerant >= 3).
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== ===========================================================
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0 always panic on uncorrected errors, log corrected errors
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1 panic or SIGBUS on uncorrected errors, log corrected errors
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2 SIGBUS or log uncorrected errors, log corrected errors
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3 never panic or SIGBUS, log all errors (for testing only)
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== ===========================================================
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Default: 1
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Note this only makes a difference if the CPU allows recovery
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from a machine check exception. Current x86 CPUs generally
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do not.
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What: /sys/devices/system/machinecheck/machinecheckX/trigger
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Contact: Andi Kleen <ak@linux.intel.com>
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Date: Feb, 2007
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Description:
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The entries appear for each CPU, but they are truly shared
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between all CPUs.
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Program to run when a machine check event is detected.
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This is an alternative to running mcelog regularly from cron
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and allows to detect events faster.
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What: /sys/devices/system/machinecheck/machinecheckX/monarch_timeout
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Contact: Andi Kleen <ak@linux.intel.com>
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Date: Feb, 2007
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Description:
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How long to wait for the other CPUs to machine check too on a
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exception. 0 to disable waiting for other CPUs.
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Unit: us
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What: /sys/devices/system/machinecheck/machinecheckX/ignore_ce
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Contact: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
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Date: Jun 2009
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Description:
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Disables polling and CMCI for corrected errors.
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All corrected events are not cleared and kept in bank MSRs.
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What: /sys/devices/system/machinecheck/machinecheckX/dont_log_ce
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Contact: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
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Date: Jun 2009
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Description:
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Disables logging for corrected errors.
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All reported corrected errors will be cleared silently.
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This option will be useful if you never care about corrected
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errors.
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What: /sys/devices/system/machinecheck/machinecheckX/cmci_disabled
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Contact: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
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Date: Jun 2009
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Description:
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Disables the CMCI feature.
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