Diffstat (limited to 'Documentation/x86')
2 files changed, 44 insertions, 8 deletions
diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
index 2db5893d6c97..29a6ff8bc7d3 100644
@@ -5,21 +5,51 @@ only the AMD64 specific ones are listed here.
- mce=off disable machine check
- mce=bootlog Enable logging of machine checks left over from booting.
- Disabled by default on AMD because some BIOS leave bogus ones.
- If your BIOS doesn't do that it's a good idea to enable though
- to make sure you log even machine check events that result
- in a reboot. On Intel systems it is enabled by default.
+ Please see Documentation/x86/x86_64/machinecheck for sysfs runtime tunables.
+ Disable machine check
+ Disable CMCI(Corrected Machine Check Interrupt) that
+ Intel processor supports. Usually this disablement is
+ not recommended, but it might be handy if your hardware
+ is misbehaving.
+ Note that you'll get more problems without CMCI than with
+ due to the shared banks, i.e. you might get duplicated
+ error logs.
+ Don't make logs for corrected errors. All events reported
+ as corrected are silently cleared by OS.
+ This option will be useful if you have no interest in any
+ of corrected errors.
+ Disable features for corrected errors, e.g. polling timer
+ and CMCI. All events reported as corrected are not cleared
+ by OS and remained in its error banks.
+ Usually this disablement is not recommended, however if
+ there is an agent checking/clearing corrected errors
+ (e.g. BIOS or hardware monitoring applications), conflicting
+ with OS's error handling, and you cannot deactivate the agent,
+ then this option will be a help.
+ Enable logging of machine checks left over from booting.
+ Disabled by default on AMD because some BIOS leave bogus ones.
+ If your BIOS doesn't do that it's a good idea to enable though
+ to make sure you log even machine check events that result
+ in a reboot. On Intel systems it is enabled by default.
Disable boot machine check logging.
- mce=tolerancelevel (number)
+ mce=tolerancelevel[,monarchtimeout] (number,number)
+ tolerance levels:
0: always panic on uncorrected errors, log corrected errors
1: panic or SIGBUS on uncorrected errors, log corrected errors
2: SIGBUS or log uncorrected errors, log corrected errors
3: never panic or SIGBUS, log all errors (for testing only)
Default is 1
Can be also set using sysfs which is preferable.
+ Sets the time in us to wait for other CPUs on machine checks. 0
+ to disable.
nomce (for compatibility with i386): same as mce=off
diff --git a/Documentation/x86/x86_64/machinecheck b/Documentation/x86/x86_64/machinecheck
index a05e58e7b159..b1fb30273286 100644
@@ -41,7 +41,9 @@ check_interval
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.
+ maximum polling interval. 0 means no polling for corrected machine
+ check errors (but some corrected errors might be still reported
+ in other ways)
Tolerance level. When a machine check exception occurs for a non
@@ -67,6 +69,10 @@ 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.
+ How long to wait for the other CPUs to machine check too on a
+ exception. 0 to disable waiting for other CPUs.
+ Unit: us
TBD document entries for AMD threshold interrupt configuration