[PATCH 3/3] doc/hotplug: update man and --help

Hari Bathini hbathini at linux.ibm.com
Mon Jun 10 02:19:46 PDT 2024



On 22/05/24 6:43 pm, Sourabh Jain wrote:
> Update the man page and --help option to make the description of the
> --hotplug option easier to understand.
> 
> Cc: Aditya Gupta <adityag at linux.ibm.com>
> Cc: Baoquan He <bhe at redhat.com>
> Cc: Coiby Xu <coxu at redhat.com>
> Cc: Hari Bathini <hbathini at linux.ibm.com>
> Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
> Signed-off-by: Sourabh Jain <sourabhjain at linux.ibm.com>
> ---
>   kexec/kexec.8 | 8 ++++----
>   kexec/kexec.c | 3 ++-
>   2 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/kexec/kexec.8 b/kexec/kexec.8
> index 9e995fe..7dddae9 100644
> --- a/kexec/kexec.8
> +++ b/kexec/kexec.8
> @@ -140,10 +140,10 @@ Open a help file for
>   .BR kexec .
>   .TP
>   .B \-\-hotplug

Can we have the description changed like:

> -Setup for kernel modification of the elfcorehdr. This option performs
> -the steps needed to support kernel updates to the elfcorehdr in the
> -presence of hot un/plug and/or on/offline events. This option only
> -useful for KEXEC_LOAD syscall.
> +Helps avoid kdump kernel reload on CPU/Memory hotplug or on/offline events.
> +If this option is enabled, the kexec segments will be set up in a way that
> +the kernel can safely update them on CPU/memory hotplug and/or on/offline
> +events. This option is only useful for the KEXEC_LOAD syscall.

"Setup kexec segments such that kernel can safely update them on 
CPU/Memory hot add/remove events. If this option is enabled, kernel does
in-kernel update of kexec segments on CPU/Memory hot add/remove events.
Helps avoid the need to reload kdump kernel."


>   .TP
>   .B \-i\ (\-\-no-checks)
>   Fast reboot, no memory integrity checks.
> diff --git a/kexec/kexec.c b/kexec/kexec.c
> index 034cea6..2b06438 100644
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -1093,7 +1093,8 @@ void usage(void)
>   	       "                      back to the compatibility syscall when file based\n"
>   	       "                      syscall is not supported or the kernel did not\n"
>   	       "                      understand the image (default)\n"
> -	       " --hotplug            Setup for kernel modification of elfcorehdr.\n"

> +	       " --hotplug            Helps avoid kdump kernel reload on CPU/Memory hotplug\n"
> +	       "		      or on/offline events.\n"

"Do in-kernel update of kexec segments on CPU/Memory hot add/remove 
events. This avoids the need to reload kdump kernel."

- Hari



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