[PATCH] Documentation: update kernel parameter limit notes

James Addison posted 1 patch 2 years, 6 months ago
There is a newer version of this series
Documentation/admin-guide/kernel-parameters.rst | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
[PATCH] Documentation: update kernel parameter limit notes
Posted by James Addison 2 years, 6 months ago
There does appear to be a limit on the number of parameters accepted by the
kernel at boot-time, so this changeset updates the kernel-parameters.rst
documentation to reflect that.

Signed-off-by: James Addison <jay@jp-hosting.net>
---
 Documentation/admin-guide/kernel-parameters.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.rst
b/Documentation/admin-guide/kernel-parameters.rst
index 959f73a32..12cbf46b6 100644
--- a/Documentation/admin-guide/kernel-parameters.rst
+++ b/Documentation/admin-guide/kernel-parameters.rst
@@ -204,7 +204,8 @@ be entered as an environment variable, whereas its
absence indicates that
 it will appear as a kernel argument readable via /proc/cmdline by programs
 running once the system is up.

-The number of kernel parameters is not limited, but the length of the
+The number of kernel parameters is limited to 32 by default (128 in User Mode
+Linux), and is defined in ./init/main.c as MAX_INIT_ARGS. The length of the
 complete command line (parameters including spaces etc.) is limited to
 a fixed number of characters. This limit depends on the architecture
 and is between 256 and 4096 characters. It is defined in the file
-- 
2.39.1
Re: [PATCH] Documentation: update kernel parameter limit notes
Posted by Randy Dunlap 2 years, 6 months ago
Hi,

On 2/21/23 10:34, James Addison wrote:
> There does appear to be a limit on the number of parameters accepted by the
> kernel at boot-time, so this changeset updates the kernel-parameters.rst
> documentation to reflect that.
> 
> Signed-off-by: James Addison <jay@jp-hosting.net>
> ---
>  Documentation/admin-guide/kernel-parameters.rst | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.rst
> b/Documentation/admin-guide/kernel-parameters.rst
> index 959f73a32..12cbf46b6 100644
> --- a/Documentation/admin-guide/kernel-parameters.rst
> +++ b/Documentation/admin-guide/kernel-parameters.rst
> @@ -204,7 +204,8 @@ be entered as an environment variable, whereas its
> absence indicates that
>  it will appear as a kernel argument readable via /proc/cmdline by programs
>  running once the system is up.
> 
> -The number of kernel parameters is not limited, but the length of the
> +The number of kernel parameters is limited to 32 by default (128 in User Mode
> +Linux), and is defined in ./init/main.c as MAX_INIT_ARGS. The length of the
>  complete command line (parameters including spaces etc.) is limited to
>  a fixed number of characters. This limit depends on the architecture
>  and is between 256 and 4096 characters. It is defined in the file

I agree with your patch, but you will need to Cc: some maintainer on
your (next) email/patch so that they can apply/merge it (if they want to).

Thanks.
-- 
~Randy