diff mbox

watchdog: hpwdt: Adjust documentation to match kernel module parameters

Message ID A4930445748CDC43B8495613130746F44ECD7611@G9W0735.americas.hpqcorp.net
State Superseded
Headers show

Commit Message

Nigel Croxon March 31, 2016, 10:32 p.m. UTC
From: Nigel Croxon <nigel.croxon@hpe.com>

Date: Thu, 31 Mar 2016 09:54:56 -0400
Subject: [PATCH] watchdog: hpwdt: Adjust documentation to match latest kernel module parameters.

Adjust documentation to match latest kernel module parameters.

Signed-off-by: Nigel Croxon <nigel.croxon@hpe.com>

Signed-off-by: Thomas Mingarelli <thomas.mingarelli@hpe.com>

---
 Documentation/watchdog/hpwdt.txt |   55 ++++++++++++++++++++------------------
 1 files changed, 29 insertions(+), 26 deletions(-)

-- 
1.7.1

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Comments

Nigel Croxon April 1, 2016, 10:19 a.m. UTC | #1
Hello Roeck,

I did the changes, Tom did the review and is in the sign-off-path.

-Nigel


-----Original Message-----
From: Guenter Roeck [mailto:linux@roeck-us.net] 

Sent: Thursday, March 31, 2016 8:06 PM
To: Croxon, Nigel <nigel.croxon@hpe.com>
Cc: wim@iguana.be; linux-watchdog@vger.kernel.org
Subject: Re: [PATCH] watchdog: hpwdt: Adjust documentation to match kernel module parameters

On Thu, Mar 31, 2016 at 10:32:32PM +0000, Croxon, Nigel wrote:
> From: Nigel Croxon <nigel.croxon@hpe.com>

> Date: Thu, 31 Mar 2016 09:54:56 -0400

> Subject: [PATCH] watchdog: hpwdt: Adjust documentation to match latest kernel module parameters.

> 

> Adjust documentation to match latest kernel module parameters.

> 

> Signed-off-by: Nigel Croxon <nigel.croxon@hpe.com>

> Signed-off-by: Thomas Mingarelli <thomas.mingarelli@hpe.com>


Are the two of you in the sign-off path, or did one of you review the changes ?

> ---

>  Documentation/watchdog/hpwdt.txt |   55 ++++++++++++++++++++------------------

>  1 files changed, 29 insertions(+), 26 deletions(-)

> 

> diff --git a/Documentation/watchdog/hpwdt.txt 

> b/Documentation/watchdog/hpwdt.txt

> index 9488078..0cb6c16 100644

> --- a/Documentation/watchdog/hpwdt.txt

> +++ b/Documentation/watchdog/hpwdt.txt

> @@ -1,64 +1,67 @@

> -Last reviewed: 06/02/2009

> +Last reviewed: 03/31/2016

>  

> -                     HP iLO2 NMI Watchdog Driver

> -              NMI sourcing for iLO2 based ProLiant Servers

> +                     HPE iLO NMI Watchdog Driver

> +              NMI sourcing for iLO based ProLiant Servers

>                       Documentation and Driver by

> -              Thomas Mingarelli <thomas.mingarelli@hp.com>

> +              Thomas Mingarelli <thomas.mingarelli@hpe.com>

>  

> - The HP iLO2 NMI Watchdog driver is a kernel module that provides 

> basic

> + The HPE iLO NMI Watchdog driver is a kernel module that provides 

> + basic

>   watchdog functionality and the added benefit of NMI sourcing. Both the

>   watchdog functionality and the NMI sourcing capability need to be enabled

>   by the user. Remember that the two modes are not dependent on one another.

>   A user can have the NMI sourcing without the watchdog timer and vice-versa.

> + All references to iLO in this document imply it also works on iLO2 

> + and all subsequent generations.

>  

>   Watchdog functionality is enabled like any other common watchdog driver. That

>   is, an application needs to be started that kicks off the watchdog timer. A

>   basic application exists in the Documentation/watchdog/src directory called

>   watchdog-test.c. Simply compile the C file and kick it off. If the 

> system

> - gets into a bad state and hangs, the HP ProLiant iLO 2 timer 

> register will

> + gets into a bad state and hangs, the HPE ProLiant iLO timer register 

> + will

>   not be updated in a timely fashion and a hardware system reset (also known as

>   an Automatic Server Recovery (ASR)) event will occur.

>  

> - The hpwdt driver also has four (4) module parameters. They are the following:

> + The hpwdt driver also has three (3) module parameters. They are the following:

>  

> - soft_margin - allows the user to set the watchdog timer value

> - allow_kdump - allows the user to save off a kernel dump image after 

> an NMI

> + soft_margin - allows the user to set the watchdog timer value.

> +               Default value is 30 seconds.

> + allow_kdump - allows the user to save off a kernel dump image after an NMI.

> +               Default value is 1/ON

>   nowayout    - basic watchdog parameter that does not allow the timer to

>                 be restarted or an impending ASR to be escaped.

> - priority    - determines whether or not the hpwdt driver is first on the

> -               die_notify list to handle NMIs or last. The default value

> -               for this module parameter is 0 or LAST. If the user wants to

> -               enable NMI sourcing then reload the hpwdt driver with

> -               priority=1 (and boot with nmi_watchdog=0).

> +               Default valus is set when compiling the kernel. If it 

> + is set


s/valus/value/

> +               to "Y", then there is not way of disabling the watchdog once

> +               it has been started.

>  

>   NOTE: More information about watchdog drivers in general, including the ioctl

>         interface to /dev/watchdog can be found in

>         Documentation/watchdog/watchdog-api.txt and Documentation/IPMI.txt.

>  

> - The priority parameter was introduced due to other kernel software 

> that relied

> - on handling NMIs (like oprofile). Keeping hpwdt's priority at 0 (or 

> LAST)

> - enables the users of NMIs for non critical events to be work as expected.

> -

>   The NMI sourcing capability is disabled by default due to the inability to

>   distinguish between "NMI Watchdog Ticks" and "HW generated NMI events" in the

>   Linux kernel. What this means is that the hpwdt nmi handler code is called

>   each time the NMI signal fires off. This could amount to several thousands of

>   NMIs in a matter of seconds. If a user sees the Linux kernel's "dazed and

>   confused" message in the logs or if the system gets into a hung 

> state, then

> - the hpwdt driver can be reloaded with the "priority" module 

> parameter set

> - (priority=1).

> + the hpwdt driver can be reloaded. 

>  

>   1. If the kernel has not been booted with nmi_watchdog turned off then

> -    edit /boot/grub/menu.lst and place the nmi_watchdog=0 at the end of the

> -    currently booting kernel line.

> +    edit and place the nmi_watchdog=0 at the end of the currently booting

> +    kernel line. Depending on your Linux distribution and platform setup:

> +    For non-UEFI systems

> +       /boot/grub/grub.conf   or

> +       /boot/grub/menu.lst

> +    For UEFI systems

> +      /boot/efi/EFI/distroname/grub.conf   or

> +      /boot/efi/efi/distroname/elilo.conf

>   2. reboot the sever

>   3. Once the system comes up perform a rmmod hpwdt

> - 4. insmod /lib/modules/`uname 

> -r`/kernel/drivers/char/watchdog/hpwdt.ko priority=1

> + 4. insmod /lib/modules/`uname -r`/kernel/drivers/watchdog/hpwdt.ko


Can you update this text to refer to modprobe / modprobe -r instead of insmod / rmmod ?

>  

>   Now, the hpwdt can successfully receive and source the NMI and 

> provide a log

> - message that details the reason for the NMI (as determined by the HP BIOS).

> + message that details the reason for the NMI (as determined by the HPE BIOS).

>  

> - Below is a list of NMIs the HP BIOS understands along with the 

> associated

> + Below is a list of NMIs the HPE BIOS understands along with the 

> + associated

>   code (reason):

>  

>  	No source found                00h

> @@ -92,4 +95,4 @@ Last reviewed: 06/02/2009

>  

>  

>   -- Tom Mingarelli

> -    (thomas.mingarelli@hp.com)

> +    (thomas.mingarelli@hpe.com)

> --

> 1.7.1

> 

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diff mbox

Patch

diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt
index 9488078..0cb6c16 100644
--- a/Documentation/watchdog/hpwdt.txt
+++ b/Documentation/watchdog/hpwdt.txt
@@ -1,64 +1,67 @@ 
-Last reviewed: 06/02/2009
+Last reviewed: 03/31/2016
 
-                     HP iLO2 NMI Watchdog Driver
-              NMI sourcing for iLO2 based ProLiant Servers
+                     HPE iLO NMI Watchdog Driver
+              NMI sourcing for iLO based ProLiant Servers
                      Documentation and Driver by
-              Thomas Mingarelli <thomas.mingarelli@hp.com>
+              Thomas Mingarelli <thomas.mingarelli@hpe.com>
 
- The HP iLO2 NMI Watchdog driver is a kernel module that provides basic
+ The HPE iLO NMI Watchdog driver is a kernel module that provides basic
  watchdog functionality and the added benefit of NMI sourcing. Both the
  watchdog functionality and the NMI sourcing capability need to be enabled
  by the user. Remember that the two modes are not dependent on one another.
  A user can have the NMI sourcing without the watchdog timer and vice-versa.
+ All references to iLO in this document imply it also works on iLO2 and all
+ subsequent generations.
 
  Watchdog functionality is enabled like any other common watchdog driver. That
  is, an application needs to be started that kicks off the watchdog timer. A
  basic application exists in the Documentation/watchdog/src directory called
  watchdog-test.c. Simply compile the C file and kick it off. If the system
- gets into a bad state and hangs, the HP ProLiant iLO 2 timer register will
+ gets into a bad state and hangs, the HPE ProLiant iLO timer register will
  not be updated in a timely fashion and a hardware system reset (also known as
  an Automatic Server Recovery (ASR)) event will occur.
 
- The hpwdt driver also has four (4) module parameters. They are the following:
+ The hpwdt driver also has three (3) module parameters. They are the following:
 
- soft_margin - allows the user to set the watchdog timer value
- allow_kdump - allows the user to save off a kernel dump image after an NMI
+ soft_margin - allows the user to set the watchdog timer value.
+               Default value is 30 seconds.
+ allow_kdump - allows the user to save off a kernel dump image after an NMI.
+               Default value is 1/ON
  nowayout    - basic watchdog parameter that does not allow the timer to
                be restarted or an impending ASR to be escaped.
- priority    - determines whether or not the hpwdt driver is first on the
-               die_notify list to handle NMIs or last. The default value
-               for this module parameter is 0 or LAST. If the user wants to
-               enable NMI sourcing then reload the hpwdt driver with
-               priority=1 (and boot with nmi_watchdog=0).
+               Default valus is set when compiling the kernel. If it is set
+               to "Y", then there is not way of disabling the watchdog once
+               it has been started.
 
  NOTE: More information about watchdog drivers in general, including the ioctl
        interface to /dev/watchdog can be found in
        Documentation/watchdog/watchdog-api.txt and Documentation/IPMI.txt.
 
- The priority parameter was introduced due to other kernel software that relied
- on handling NMIs (like oprofile). Keeping hpwdt's priority at 0 (or LAST)
- enables the users of NMIs for non critical events to be work as expected.
-
  The NMI sourcing capability is disabled by default due to the inability to
  distinguish between "NMI Watchdog Ticks" and "HW generated NMI events" in the
  Linux kernel. What this means is that the hpwdt nmi handler code is called
  each time the NMI signal fires off. This could amount to several thousands of
  NMIs in a matter of seconds. If a user sees the Linux kernel's "dazed and
  confused" message in the logs or if the system gets into a hung state, then
- the hpwdt driver can be reloaded with the "priority" module parameter set
- (priority=1).
+ the hpwdt driver can be reloaded. 
 
  1. If the kernel has not been booted with nmi_watchdog turned off then
-    edit /boot/grub/menu.lst and place the nmi_watchdog=0 at the end of the
-    currently booting kernel line.
+    edit and place the nmi_watchdog=0 at the end of the currently booting
+    kernel line. Depending on your Linux distribution and platform setup:
+    For non-UEFI systems
+       /boot/grub/grub.conf   or
+       /boot/grub/menu.lst
+    For UEFI systems
+      /boot/efi/EFI/distroname/grub.conf   or
+      /boot/efi/efi/distroname/elilo.conf
  2. reboot the sever
  3. Once the system comes up perform a rmmod hpwdt
- 4. insmod /lib/modules/`uname -r`/kernel/drivers/char/watchdog/hpwdt.ko priority=1
+ 4. insmod /lib/modules/`uname -r`/kernel/drivers/watchdog/hpwdt.ko 
 
  Now, the hpwdt can successfully receive and source the NMI and provide a log
- message that details the reason for the NMI (as determined by the HP BIOS).
+ message that details the reason for the NMI (as determined by the HPE BIOS).
 
- Below is a list of NMIs the HP BIOS understands along with the associated
+ Below is a list of NMIs the HPE BIOS understands along with the associated
  code (reason):
 
 	No source found                00h
@@ -92,4 +95,4 @@  Last reviewed: 06/02/2009
 
 
  -- Tom Mingarelli
-    (thomas.mingarelli@hp.com)
+    (thomas.mingarelli@hpe.com)