Re: [PATCH] dynamic_debug: allow to set dynamic debug flags right at module load time

[Jason Baron <jbaron@redhat.com>]

On Thu, May 27, 2010 at 07:05:43AM +0200, Roman Fietze wrote:
> Hello Jason,
> 
> On Wednesday 26 May 2010 20:35:59 Jason Baron wrote:
> 
> > ... we want this to be runtime configurable.
> > That is, we probably want this implemented as a module parameter, not as
> > a compile time thing. something like: modprobe module verbose=1
> 
> Kind of
> 
> #define dynamic_pr_debug(fmt, ...) do {					\
> 	...
> 		DEBUG_HASH2, __LINE__,					\
> 		verbose ? _DPRINTK_FLAGS_PRINT : _DPRINTK_FLAGS_DEFAULT}; \
> 	...
> 
> But what if verbose isn't there?
> 
> Or something smarter inside dynamic_debug_setup() or
> ddebug_add_module() looking for a module symbol or parameter with that
> name?
> 

right, i think we want to add something inside ddebug_add_module() that
recognizes if the module was loaded with verbose=1. I think you can get
at the parameters via module->kp, which we need to pass in as well.

There is also a naming issue, in that if we "reserve" the param
"verbose", how do we make sure no other module wants to use that as a
module parameter name. Or maybe it doesn't matter if we don't consume
the parameter. That is, the parameter can mean 2 things. not sure.

thanks,

-Jason