Re: [PATCH V2 5/5] panic: add note that panic_print interface is deprecated

[Petr Mladek <pmladek@suse.com>]

On Mon 2025-06-16 09:45:16, Lance Yang wrote:
> 
> 
> On 2025/6/16 09:08, Feng Tang wrote:
> > Long term wise, the 'panic_sys_info' should be the only controlling
> > interface, which can be referred by other modules.
> > 
> > Suggested-by: Petr Mladek <pmladek@suse.com>
> > Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
> > ---
> >   kernel/panic.c | 9 ++++++++-
> >   1 file changed, 8 insertions(+), 1 deletion(-)
> > 
> > diff --git a/kernel/panic.c b/kernel/panic.c
> > index ea238f7d4b54..e8a05fc6b733 100644
> > --- a/kernel/panic.c
> > +++ b/kernel/panic.c
> > @@ -76,6 +76,13 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
> >   EXPORT_SYMBOL(panic_notifier_list);
> >   #ifdef CONFIG_SYSCTL
> > +static int sysctl_panic_print_handler(const struct ctl_table *table, int write,
> > +			   void *buffer, size_t *lenp, loff_t *ppos)
> > +{
> > +	printk_once("panic: 'panic_print' sysctl interface will be obsoleted by 'panic_sys_info' interface.\n");
> 
> Hmm... I would get scared for a second when I read messages prefixed with
> "panic:"
> from dmesg. That prefix should have a very specific meaning ;)
> 
> Well, we can just change the prefix to something more neutral:
> 
> printk_once("Kernel: 'panic_print' sysctl interface will be obsoleted by
> 'panic_sys_info' interface.\n");

I agree that this looks better.

That said, I am not a native speaker but I think the "will be
obsoleted" is not correct. I would use "has been obsoleted" instead.

Also the messages should use a particular loglevel, e.g. KERN_INFO.

I would do:

	pr_info_once("Kernel: 'panic_print' sysctl interface has been obsoleted by 'panic_sys_info' interface.\n");


> 
> > +	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
> > +}
> > +

Best Regards,
Petr