Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog filedocumentation

From: Cyrill Gorcunov
Date: Thu Oct 30 2008 - 11:45:57 EST


[Aristeu Rozanski - Thu, Oct 30, 2008 at 11:17:14AM -0400]
| This patch updates the /proc/sys/kernel/nmi_watchdog documentation.
|
| Signed-off-by: Aristeu Rozanski <aris@xxxxxxxxxx>
|
| ---
| Documentation/filesystems/proc.txt | 13 ++++++++-----
| Documentation/nmi_watchdog.txt | 5 +++++
| 2 files changed, 13 insertions(+), 5 deletions(-)
|
| --- linus-2.6.orig/Documentation/nmi_watchdog.txt 2008-10-24 11:41:30.000000000 -0400
| +++ linus-2.6/Documentation/nmi_watchdog.txt 2008-10-29 16:38:12.000000000 -0400
| @@ -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
| +in boot time.
| +
| NOTE: In kernels prior to 2.4.2-ac18 the NMI-oopser is enabled unconditionally
| on x86 SMP boxes.
|
| --- linus-2.6.orig/Documentation/filesystems/proc.txt 2008-10-24 11:41:28.000000000 -0400
| +++ linus-2.6/Documentation/filesystems/proc.txt 2008-10-30 11:16:36.000000000 -0400
| @@ -1336,12 +1336,15 @@ panic controls already in that directory
| nmi_watchdog
| ------------
|
| -Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero
| +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.
| -
| -Because the NMI watchdog shares registers with oprofile, by disabling the NMI
| -watchdog, oprofile may have more registers to utilize.
| +determine whether or not they are still functioning properly. Currently,
| +passing "nmi_watchdog=" parameter in boot time is required for this function
| +to work.
| +
| +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
| ------
|

Hi Aristeu,

by reading this patch I found that maybe it's time to start
using nmi_watchdog=[lapic,ioapic] instead of 1 and 2? We could make
them as alases to existing numbers. Thoughts?

- Cyrill -
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