x86, mce: Add boot options for corrected errors

This patch introduces three boot options (no_cmci, dont_log_ce
and ignore_ce) to control handling for corrected errors.

The "mce=no_cmci" boot option disables the CMCI feature.

Since CMCI is a new feature so having boot controls to disable
it will be a help if the hardware is misbehaving.

The "mce=dont_log_ce" boot option 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.

The "mce=ignore_ce" boot option disables features for corrected
errors, i.e. polling timer and cmci.  All corrected events are
not cleared and kept in bank MSRs.

Usually this disablement is not recommended, however it will be
a help if there are some conflict with the BIOS or hardware
monitoring applications etc., that clears corrected events in
banks instead of OS.

[ And trivial cleanup (space -> tab) for doc is included. ]

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <4A30ACDF.5030408@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Hidetoshi Seto
2009-06-11 16:06:07 +09:00
committed by Ingo Molnar
parent 77e26cca20
commit 62fdac5913
4 changed files with 52 additions and 8 deletions
+30 -6
View File
@@ -7,12 +7,36 @@ Machine check
Please see Documentation/x86/x86_64/machinecheck for sysfs runtime tunables.
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.
mce=off
Disable machine check
mce=no_cmci
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.
mce=dont_log_ce
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.
mce=ignore_ce
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.
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.
mce=nobootlog
Disable boot machine check logging.
mce=tolerancelevel[,monarchtimeout] (number,number)