x86, nmi-watchdog: update procfs nmi_watchdog file documentation v2

Impact: improve documentation

This patch updates the /proc/sys/kernel/nmi_watchdog documentation.
Updated: included Randy Dunlap's corrections.

Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Aristeu Rozanski 2008-10-30 13:08:50 -04:00 committed by Ingo Molnar
parent b062f841b5
commit 8a1c8eb75b
2 changed files with 11 additions and 3 deletions

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@ -1338,10 +1338,13 @@ nmi_watchdog
Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero
the NMI watchdog is enabled and will continuously test all online cpus to
determine whether or not they are still functioning properly.
determine whether or not they are still functioning properly. Currently,
passing "nmi_watchdog=" parameter at boot time is required for this function
to work.
Because the NMI watchdog shares registers with oprofile, by disabling the NMI
watchdog, oprofile may have more registers to utilize.
If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the
NMI watchdog shares registers with oprofile. By disabling the NMI watchdog,
oprofile may have more registers to utilize.
msgmni
------

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@ -69,6 +69,11 @@ to the overall system performance.
On x86 nmi_watchdog is disabled by default so you have to enable it with
a boot time parameter.
It's possible to disable the NMI watchdog in run-time by writing "0" to
/proc/sys/kernel/nmi_watchdog. Writing "1" to the same file will re-enable
the NMI watchdog. Notice that you still need to use "nmi_watchdog=" parameter
at boot time.
NOTE: In kernels prior to 2.4.2-ac18 the NMI-oopser is enabled unconditionally
on x86 SMP boxes.