2017-12-10 07:48:54

by Crystal Wood

Subject: [PATCH] Documentation: Better document the hardlockup_panic sysctl

Commit ac1f591249d95372f ("kernel/watchdog.c: add sysctl knob
hardlockup_panic") added the hardlockup_panic sysctl, but did not add it
to Documentation/sysctl/kernel.txt. Add this, and reference it from the
corresponding entry in Documentation/admin-guide/kernel-parameters.txt.

Signed-off-by: Scott Wood <[email protected]>
---
Documentation/admin-guide/kernel-parameters.txt | 3 +++
Documentation/sysctl/kernel.txt | 14 ++++++++++++++
2 files changed, 17 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 6571fbfdb2a1..dfb7c35b5826 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2538,6 +2538,9 @@
This is useful when you use a panic=... timeout and
need the box quickly up again.

+ These settings can be accessed at runtime via
+ the nmi_watchdog and hardlockup_panic sysctls.
+
netpoll.carrier_timeout=
[NET] Specifies amount of time (in seconds) that
netpoll should wait for a carrier. By default netpoll
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 694968c7523c..63663039acb7 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -34,6 +34,7 @@ show up in /proc/sys/kernel:
- hostname
- hotplug
- hardlockup_all_cpu_backtrace
+- hardlockup_panic
- hung_task_panic
- hung_task_check_count
- hung_task_timeout_secs
@@ -313,6 +314,19 @@ will be initiated.
1: on detection capture more debug information.
==============================================================

+hardlockup_panic:
+
+This parameter can be used to control whether the kernel panics
+when a hard lockup is detected.
+
+ 0 - don't panic on hard lockup
+ 1 - panic on hard lockup
+
+See Documentation/lockup-watchdogs.txt for more information. This can
+also be set using the nmi_watchdog kernel parameter.
+
+==============================================================
+
hotplug:

Path for the hotplug policy agent.
--
2.9.5

2017-12-10 11:35:21

by Chris von Recklinghausen

Subject: Re: [PATCH] Documentation: Better document the hardlockup_panic sysctl

Ack

Sent from my iPhone

> On Dec 10, 2017, at 2:48 AM, Scott Wood <[email protected]> wrote:
>
> Commit ac1f591249d95372f ("kernel/watchdog.c: add sysctl knob
> hardlockup_panic") added the hardlockup_panic sysctl, but did not add it
> to Documentation/sysctl/kernel.txt. Add this, and reference it from the
> corresponding entry in Documentation/admin-guide/kernel-parameters.txt.
>
> Signed-off-by: Scott Wood <[email protected]>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 3 +++
> Documentation/sysctl/kernel.txt | 14 ++++++++++++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 6571fbfdb2a1..dfb7c35b5826 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2538,6 +2538,9 @@
> This is useful when you use a panic=... timeout and
> need the box quickly up again.
>
> + These settings can be accessed at runtime via
> + the nmi_watchdog and hardlockup_panic sysctls.
> +
> netpoll.carrier_timeout=
> [NET] Specifies amount of time (in seconds) that
> netpoll should wait for a carrier. By default netpoll
> diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
> index 694968c7523c..63663039acb7 100644
> --- a/Documentation/sysctl/kernel.txt
> +++ b/Documentation/sysctl/kernel.txt
> @@ -34,6 +34,7 @@ show up in /proc/sys/kernel:
> - hostname
> - hotplug
> - hardlockup_all_cpu_backtrace
> +- hardlockup_panic
> - hung_task_panic
> - hung_task_check_count
> - hung_task_timeout_secs
> @@ -313,6 +314,19 @@ will be initiated.
> 1: on detection capture more debug information.
> ==============================================================
>
> +hardlockup_panic:
> +
> +This parameter can be used to control whether the kernel panics
> +when a hard lockup is detected.
> +
> + 0 - don't panic on hard lockup
> + 1 - panic on hard lockup
> +
> +See Documentation/lockup-watchdogs.txt for more information. This can
> +also be set using the nmi_watchdog kernel parameter.
> +
> +==============================================================
> +
> hotplug:
>
> Path for the hotplug policy agent.
> --
> 2.9.5
>

2017-12-11 14:43:51

by Don Zickus

Subject: Re: [PATCH] Documentation: Better document the hardlockup_panic sysctl

On Sun, Dec 10, 2017 at 01:48:46AM -0600, Scott Wood wrote:
> Commit ac1f591249d95372f ("kernel/watchdog.c: add sysctl knob
> hardlockup_panic") added the hardlockup_panic sysctl, but did not add it
> to Documentation/sysctl/kernel.txt. Add this, and reference it from the
> corresponding entry in Documentation/admin-guide/kernel-parameters.txt.

Acked-by: Don Zickus <[email protected]>

>
> Signed-off-by: Scott Wood <[email protected]>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 3 +++
> Documentation/sysctl/kernel.txt | 14 ++++++++++++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 6571fbfdb2a1..dfb7c35b5826 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2538,6 +2538,9 @@
> This is useful when you use a panic=... timeout and
> need the box quickly up again.
>
> + These settings can be accessed at runtime via
> + the nmi_watchdog and hardlockup_panic sysctls.
> +
> netpoll.carrier_timeout=
> [NET] Specifies amount of time (in seconds) that
> netpoll should wait for a carrier. By default netpoll
> diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
> index 694968c7523c..63663039acb7 100644
> --- a/Documentation/sysctl/kernel.txt
> +++ b/Documentation/sysctl/kernel.txt
> @@ -34,6 +34,7 @@ show up in /proc/sys/kernel:
> - hostname
> - hotplug
> - hardlockup_all_cpu_backtrace
> +- hardlockup_panic
> - hung_task_panic
> - hung_task_check_count
> - hung_task_timeout_secs
> @@ -313,6 +314,19 @@ will be initiated.
> 1: on detection capture more debug information.
> ==============================================================
>
> +hardlockup_panic:
> +
> +This parameter can be used to control whether the kernel panics
> +when a hard lockup is detected.
> +
> + 0 - don't panic on hard lockup
> + 1 - panic on hard lockup
> +
> +See Documentation/lockup-watchdogs.txt for more information. This can
> +also be set using the nmi_watchdog kernel parameter.
> +
> +==============================================================
> +
> hotplug:
>
> Path for the hotplug policy agent.
> --
> 2.9.5
>

2017-12-11 21:56:27

by Jonathan Corbet

Subject: Re: [PATCH] Documentation: Better document the hardlockup_panic sysctl

On Sun, 10 Dec 2017 01:48:46 -0600
Scott Wood <[email protected]> wrote:

> Commit ac1f591249d95372f ("kernel/watchdog.c: add sysctl knob
> hardlockup_panic") added the hardlockup_panic sysctl, but did not add it
> to Documentation/sysctl/kernel.txt. Add this, and reference it from the
> corresponding entry in Documentation/admin-guide/kernel-parameters.txt.

Applied to the docs tree, thanks.

jon