Commit 9c44bc03fff4 ("softlockup: allow panic on lockup") added the
softlockup_panic sysctl, but didn't add information about it to the file
Documentation/admin-guide/sysctl/kernel.rst (which in that time certainly
wasn't rst and had other name!).
This patch just adds the respective documentation and references it from
the corresponding entry in Documentation/admin-guide/kernel-parameters.txt.
This patch was strongly based on Scott Wood's commit d22881dc13b6
("Documentation: Better document the hardlockup_panic sysctl").
Signed-off-by: Guilherme G. Piccoli <[email protected]>
---
Documentation/admin-guide/kernel-parameters.txt | 6 +++---
Documentation/admin-guide/sysctl/kernel.rst | 13 +++++++++++++
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index c07815d230bc..adf77ead02c3 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4515,9 +4515,9 @@
A nonzero value instructs the soft-lockup detector
to panic the machine when a soft-lockup occurs. This
- is also controlled by CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC
- which is the respective build-time switch to that
- functionality.
+ is also controlled by kernel.softlockup_panic sysctl
+ and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
+ respective build-time switch to that functionality.
softlockup_all_cpu_backtrace=
[KNL] Should the soft-lockup detector generate
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index def074807cee..95b2f3256323 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -95,6 +95,7 @@ show up in /proc/sys/kernel:
- shmmax [ sysv ipc ]
- shmmni
- softlockup_all_cpu_backtrace
+- softlockup_panic
- soft_watchdog
- stack_erasing
- stop-a [ SPARC only ]
@@ -1029,6 +1030,18 @@ NMI.
1: on detection capture more debug information.
+softlockup_panic:
+=================
+
+This parameter can be used to control whether the kernel panics when
+a soft lockup is detected.
+
+0: don't panic on soft lockup
+1: panic on soft lockup
+
+This can also be set using the softlockup_panic kernel parameter.
+
+
soft_watchdog:
==============
--
2.24.1
On Tue, Mar 10, 2020 at 12:15:03PM -0300, Guilherme G. Piccoli wrote:
> Commit 9c44bc03fff4 ("softlockup: allow panic on lockup") added the
> softlockup_panic sysctl, but didn't add information about it to the file
> Documentation/admin-guide/sysctl/kernel.rst (which in that time certainly
> wasn't rst and had other name!).
>
> This patch just adds the respective documentation and references it from
> the corresponding entry in Documentation/admin-guide/kernel-parameters.txt.
>
> This patch was strongly based on Scott Wood's commit d22881dc13b6
> ("Documentation: Better document the hardlockup_panic sysctl").
>
> Signed-off-by: Guilherme G. Piccoli <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
-Kees
> ---
> Documentation/admin-guide/kernel-parameters.txt | 6 +++---
> Documentation/admin-guide/sysctl/kernel.rst | 13 +++++++++++++
> 2 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index c07815d230bc..adf77ead02c3 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4515,9 +4515,9 @@
>
> A nonzero value instructs the soft-lockup detector
> to panic the machine when a soft-lockup occurs. This
> - is also controlled by CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC
> - which is the respective build-time switch to that
> - functionality.
> + is also controlled by kernel.softlockup_panic sysctl
> + and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
> + respective build-time switch to that functionality.
>
> softlockup_all_cpu_backtrace=
> [KNL] Should the soft-lockup detector generate
> diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
> index def074807cee..95b2f3256323 100644
> --- a/Documentation/admin-guide/sysctl/kernel.rst
> +++ b/Documentation/admin-guide/sysctl/kernel.rst
> @@ -95,6 +95,7 @@ show up in /proc/sys/kernel:
> - shmmax [ sysv ipc ]
> - shmmni
> - softlockup_all_cpu_backtrace
> +- softlockup_panic
> - soft_watchdog
> - stack_erasing
> - stop-a [ SPARC only ]
> @@ -1029,6 +1030,18 @@ NMI.
> 1: on detection capture more debug information.
>
>
> +softlockup_panic:
> +=================
> +
> +This parameter can be used to control whether the kernel panics when
> +a soft lockup is detected.
> +
> +0: don't panic on soft lockup
> +1: panic on soft lockup
> +
> +This can also be set using the softlockup_panic kernel parameter.
> +
> +
> soft_watchdog:
> ==============
>
> --
> 2.24.1
>
--
Kees Cook
On Tue, 10 Mar 2020 12:15:03 -0300
"Guilherme G. Piccoli" <[email protected]> wrote:
> Commit 9c44bc03fff4 ("softlockup: allow panic on lockup") added the
> softlockup_panic sysctl, but didn't add information about it to the file
> Documentation/admin-guide/sysctl/kernel.rst (which in that time certainly
> wasn't rst and had other name!).
>
> This patch just adds the respective documentation and references it from
> the corresponding entry in Documentation/admin-guide/kernel-parameters.txt.
>
> This patch was strongly based on Scott Wood's commit d22881dc13b6
> ("Documentation: Better document the hardlockup_panic sysctl").
>
> Signed-off-by: Guilherme G. Piccoli <[email protected]>
So this doesn't even come close to applying; could you respin it against
docs-next, please?
> Documentation/admin-guide/kernel-parameters.txt | 6 +++---
> Documentation/admin-guide/sysctl/kernel.rst | 13 +++++++++++++
> 2 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index c07815d230bc..adf77ead02c3 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4515,9 +4515,9 @@
>
> A nonzero value instructs the soft-lockup detector
> to panic the machine when a soft-lockup occurs. This
> - is also controlled by CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC
> - which is the respective build-time switch to that
> - functionality.
> + is also controlled by kernel.softlockup_panic sysctl
..and while you're at it, make it "*the* kernel.softlockup_panic sysctl" :)
Thanks,
jon
On Tue, Mar 10, 2020 at 2:05 PM Jonathan Corbet <[email protected]> wrote:
> So this doesn't even come close to applying; could you respin it against
> docs-next, please?
Sure, will resubmit soon. I understand docs-next is just linux-next
correct? I couldn't find any specific docs tree on kernel.org ...
>
> ..and while you're at it, make it "*the* kernel.softlockup_panic sysctl" :)
Sure! Thanks for the review,
Guilherme
On Tue, 10 Mar 2020 15:20:15 -0300
Guilherme Piccoli <[email protected]> wrote:
> On Tue, Mar 10, 2020 at 2:05 PM Jonathan Corbet <[email protected]> wrote:
> > So this doesn't even come close to applying; could you respin it against
> > docs-next, please?
>
> Sure, will resubmit soon. I understand docs-next is just linux-next
> correct? I couldn't find any specific docs tree on kernel.org ...
That's what the MAINTAINERS file is for:
T: git git://git.lwn.net/linux.git docs-next
jon
On Tue, Mar 10, 2020 at 3:49 PM Jonathan Corbet <[email protected]> wrote:
>
> That's what the MAINTAINERS file is for:
>
> T: git git://git.lwn.net/linux.git docs-next
>
> jon
Heheh thanks Jon! I got this tree and was able to apply cleanly the V2
there (on docs-next branch), so I think we're good; let me know
otherwise.
Cheers,
Guilherme