2008-10-30 15:16:20

by Aristeu Rozanski

[permalink] [raw]
Subject: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

This patch updates the /proc/sys/kernel/nmi_watchdog documentation.

Signed-off-by: Aristeu Rozanski <[email protected]>

---
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
------


2008-10-30 15:45:56

by Cyrill Gorcunov

[permalink] [raw]
Subject: Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[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 <[email protected]>
|
| ---
| 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 -

2008-10-30 15:50:33

by Aristeu Rozanski

[permalink] [raw]
Subject: Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

> 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?
Yes, that would be useful.

--
Aristeu

2008-10-30 15:51:44

by Cyrill Gorcunov

[permalink] [raw]
Subject: Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[Aristeu Rozanski - Thu, Oct 30, 2008 at 11:51:21AM -0400]
| > 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?
| Yes, that would be useful.
|
| --
| Aristeu
|

ok, will handle it :)

- Cyrill -

2008-10-30 16:21:20

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

On Thu, 30 Oct 2008 11:17:14 -0400 Aristeu Rozanski wrote:

> This patch updates the /proc/sys/kernel/nmi_watchdog documentation.
>
> Signed-off-by: Aristeu Rozanski <[email protected]>
>
> ---
> 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.

at 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

Two spaces after a '.' is OK, fwiw.

> 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

at
> +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,

Run-on sentence: change to: oprofile;
or to: oprofile. By disabling ...

> +oprofile may have more registers to utilize.


Thanks for the updates.

---
~Randy

2008-10-30 17:08:20

by Aristeu Rozanski

[permalink] [raw]
Subject: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2

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

Signed-off-by: Aristeu Rozanski <[email protected]>

---
Documentation/filesystems/proc.txt | 11 +++++++----
Documentation/nmi_watchdog.txt | 5 +++++
2 files changed, 12 insertions(+), 4 deletions(-)

--- linus-2.6.orig/Documentation/nmi_watchdog.txt 2008-10-24 11:41:30.000000000 -0400
+++ linus-2.6/Documentation/nmi_watchdog.txt 2008-10-30 13:05:46.000000000 -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
+at 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 13:05:31.000000000 -0400
@@ -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.
-
-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 at 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
------

2008-10-30 17:14:55

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2

Aristeu Rozanski wrote:
> This patch updates the /proc/sys/kernel/nmi_watchdog documentation.
> Updated: included Randy Dunlap's corrections.
>
> Signed-off-by: Aristeu Rozanski <[email protected]>
>
> ---
> Documentation/filesystems/proc.txt | 11 +++++++----
> Documentation/nmi_watchdog.txt | 5 +++++
> 2 files changed, 12 insertions(+), 4 deletions(-)
>
> --- linus-2.6.orig/Documentation/nmi_watchdog.txt 2008-10-24 11:41:30.000000000 -0400
> +++ linus-2.6/Documentation/nmi_watchdog.txt 2008-10-30 13:05:46.000000000 -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
> +at 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 13:05:31.000000000 -0400
> @@ -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.
> -
> -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 at 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
> ------

Acked-by: Randy Dunlap <[email protected]>

Thanks.

--
~Randy

2008-10-30 18:08:33

by Ingo Molnar

[permalink] [raw]
Subject: Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2


* Randy Dunlap <[email protected]> wrote:

> > +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
> > ------
>
> Acked-by: Randy Dunlap <[email protected]>
>
> Thanks.

applied to tip/x86/nmi-watchdog, thanks guys!

Ingo