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+
+Configurable sysfs parameters for the x86-64 machine check code.
+
+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.
+
+Machine checks are organized in banks (normally associated with
+a hardware subsystem) and subevents in a bank. The exact meaning
+of the banks and subevent is CPU specific.
+
+mcelog knows how to decode them.
+
+When you see the "Machine check errors logged" message in the system
+log then mcelog should run to collect and decode machine check entries
+from /dev/mcelog. Normally mcelog should be run regularly from a cronjob.
+
+Each CPU has a directory in /sys/devices/system/machinecheck/machinecheckN
+(N = CPU number)
+
+The directory contains some configurable entries:
+
+Entries:
+
+bankNctl
+(N bank number)
+        64bit Hex bitmask enabling/disabling specific subevents for bank N
+        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
+
+The following entries appear for each CPU, but they are truly shared
+between all CPUs.
+
+check_interval
+        How often to poll for corrected machine check errors, in seconds
+        (Note output is hexademical). Default 5 minutes.
+
+tolerant
+        Tolerance level. When a machine check exception occurs for a non
+        corrected machine check the kernel can take different actions.
+        Since machine check exceptions can happen any time it is sometimes
+        risky for the kernel to kill a process because it defies
+        normal kernel locking rules. The tolerance level configures
+        how hard the kernel tries to recover even at some risk of deadlock.
+
+        0: always panic,
+        1: panic if deadlock possible,
+        2: try to avoid panic,
+        3: never panic or exit (for testing only)
+
+        Default: 1
+
+        Note this only makes a difference if the CPU allows recovery
+        from a machine check exception. Current x86 CPUs generally do not.
+
+trigger
+        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.
+
+TBD document entries for AMD threshold interrupt configuration
+
+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
+see http://one.firstfloor.org/~andi/mce.pdf