[systemd-devel] [PATCH v4] use systemd.debug on the kernel command line, not "debug"

[Jason St. John]

On Sat, Apr 5, 2014 at 4:16 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Sat, Apr 05, 2014 at 07:11:47AM +0200, Zbigniew Jędrzejewski-Szmek wrote:
>> On Thu, Apr 03, 2014 at 04:08:15PM +0200, Hannes Reinecke wrote:
>> > From: Greg KH <gregkh at linuxfoundation.org>
>> >
>> > If the kernel is started with "debug", that's for the kernel to switch
>> > into debug mode.  We should rely on a namespace for our options, like
>> > everything else (with the exception of "quiet").  Some people want to
>> > only debug the kernel, not systemd, and the opposite as well so make
>> > everyone happy.
>> Essentialy, this patch adds systemd.debug as an alias for
>> systemd.log_level=debug systemd.log_target=console. But it doesn't
>> really fix anything, just moves the initial problem to a different set
>> of options.
>
> What needs to be "fixed"?
>
>> This isn't useful. In addition, it is reasonable to use "debug" to
>> turn on verbose mode for the kernel + init combo, since in practice
>> this is what people need to diagnose boot problems.
>
> Well, the intersection of people that have a problem with both the
> kernel and systemd at boot time are probably quite small.  As a kernel
> developer, I tell people to turn on debug all the time to find issues in
> different drivers and the like.  They aren't having any problems with
> systemd, so any extra messages that it causes, isn't going to be
> helpful.
>
> Probably the same thing happens for people who are having problems with
> systemd.
>
> So I thought it would make more sense to have separate options, as the
> two things really are two different projects / code bases.  Having the
> same flag makes it easy for a small subset of people who would be doing
> work in both areas, and even then, having to add a simple
> "systemd.debug" flag to the command line for that doesn't seem to be a
> big deal.
>
> thanks,
>
> greg k-h

"init.debug" would be better than "systemd.debug", in my opinion. It
is shorter (less typing and no possible end-user confusion over
"systemd.debug" vs. "system.debug"), and it is init-agnostic. Other
init systems (OpenRC, Upstart, etc.) would be able to add their own
support for this, if they want, without requiring an init-specific
kernel parameter.

It just seems a lot simpler this way.

Jason