Re: [PATCH 1/4] Dynamic Debug: Introduce global fake module param module.ddebug - V3

[Jason Baron <jbaron@redhat.com>]

On Fri, Sep 17, 2010 at 11:52:46PM +0200, Thomas Renninger wrote:
> > Hi,
> > 
> > So i'm wondering if need to support the module.ddebug on the command
> > line?
> Yep, that would make things a bit easier...
> People would e.g. have to use ddebug_query="module pnp +p"  (which 
> already is available with the patch that is queued in linux-next)
> instead of pnp.ddebug. Not that obvious or say user friendly, though.
> 
> > The ddebug_query="module foo +p" format that you introduced does
> > the same thing. 
> No that does not work for real (not built-in) modules. Give it a try...
> The stuff needs to be set up when the module is loaded.
> If you have a real module declared as =m
> You need to call "module foo +p" when the module gets/got loaded.
> But ddebug_query="..." only gets executed once, when
> dynamic debug gets set up, far before any module got loaded.
>  

ok, to be consistent, if passing 'ddebug' as a module parameter when a
module loads, we also need for module.ddebug to work, as that is how
other module parameters work.

> > Also, we can't put those large char[] arrays on the kernel stack. They
> > probably should be global.
> Where exactly, the command line(*args)?
> 

The character arrays, that put COMMAND_LINE_SIZE and DDEBUG_STRING_SIZE
on the stack are too large. Also, ddebug_boot_parse_args() should be
marked as '__init' since it only used on boot.

thanks,

-Jason