[PATCH v3 6/6] Documentation/kernel-parameters: add/update printk_delay/boot_delay

[Petr Mladek]

On Tue 2026-07-14 17:51:31, Steven Rostedt wrote:
> On Sun, 12 Jul 2026 11:20:37 +0100
> Andrew Murray <amurray at thegoodpenguin.co.uk> wrote:
> 
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> > index 2884103b93bca7b76cd3a93946276074cf62d0a1..1118feda87b1b04543b1da0bd52c090b1fddaeac 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -650,11 +650,19 @@ Kernel parameters
> >  			See Documentation/block/cmdline-partition.rst
> >  
> >  	boot_delay=	[KNL,EARLY]
> > -			Milliseconds to delay each printk during boot.
> > -			Only works if GENERIC_CALIBRATE_DELAY is enabled,
> > -			and you may also have to specify "lpj=".  Boot_delay
> > -			values larger than 10 seconds (10000) are assumed
> > -			erroneous and ignored.
> > +			Milliseconds to delay each printk during and post boot.
> > +			Boot time delays only work if GENERIC_CALIBRATE_DELAY
> > +			is enabled.
> > +
> > +			Once booted the delay can be removed or adjusted via
> > +			the printk_delay sysctl.
> > +
> > +			Please note that you may also have to specify "lpj=".
> > +			Boot_delay values larger than 10 seconds (10000) are
> > +			assumed erroneous and ignored.
> > +
> > +			This will soon be deprecated, please use printk_delay
> > +			instead.
> >  			Format: integer
> >  
> >  	bootconfig	[KNL,EARLY]
> > @@ -5468,6 +5476,19 @@ Kernel parameters
> >  	printk.time=	Show timing data prefixed to each printk message line
> >  			Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
> >  
> > +	printk_delay=	[KNL,EARLY]
> > +			Milliseconds to delay each printk during and post boot.
> > +			Boot time delays only work if GENERIC_CALIBRATE_DELAY
> > +			is enabled.
> > +
> > +			Once booted the delay can be removed or adjusted via
> > +			the printk_delay sysctl.
> > +
> > +			Please note that you may also have to specify "lpj=".
> > +			printk_delay values larger than 10 seconds (10000) are
> > +			assumed erroneous and ignored.
> > +			Format: integer
> > +
> 
> The two parameters descriptions are identical. They should show something
> different. Is it just that the "boot_delay" name is getting deprecated?

Good point. We could remove all the details from the boot_delay
comment. Instead, we could say that it an obsolete alias to
printk_delay, will soon be drecated, ...

Best Regards,
Petr