[PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[Aristeu Rozanski]

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

Signed-off-by: Aristeu Rozanski <aris@redhat.com>

---
 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
 ------

Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[Cyrill Gorcunov]

[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@redhat.com>
| 
| ---
|  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 -

Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[Aristeu Rozanski]

> 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

Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[Cyrill Gorcunov]

[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 -

Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation

[Randy Dunlap]

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 <aris@redhat.com>
> 
> ---
>  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

[PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2

[Aristeu Rozanski]

This patch updates the /proc/sys/kernel/nmi_watchdog documentation.
Updated: included Randy Dunlap's corrections.
 
Signed-off-by: Aristeu Rozanski <aris@redhat.com>

---
 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
 ------

Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2

[Randy Dunlap]

Aristeu Rozanski wrote:
> This patch updates the /proc/sys/kernel/nmi_watchdog documentation.
> Updated: included Randy Dunlap's corrections.
>  
> Signed-off-by: Aristeu Rozanski <aris@redhat.com>
> 
> ---
>  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 <randy.dunlap@oracle.com>

Thanks.

-- 
~Randy

Re: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2

[Ingo Molnar]

* Randy Dunlap <randy.dunlap@oracle.com> 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 <randy.dunlap@oracle.com>
> 
> Thanks.

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

	Ingo