Re: SET_MODULE_OWNER?

[Jeff Garzik <jgarzik@pobox.com>]

Rusty Russell wrote:
> In message <3E91C398.9070400@pobox.com> you write:
> 
>>Rusty Russell wrote:
>>
>>>I thought it was completely useless, hence deprecated.
>>>
>>>Anyone have any reason to defend it?
>>
>>
>>It's used to allow source compatibility with all kernels, old or new.
>>
>>Thus it is in active use, and should not be removed.
> 
> 
> Inside individual drivers, or a set of compat macros, it makes sense.
> But as a general module.h primitive it doesn't.
> 
> Imagine a structure adds an owner field in 2.5.  This macro doesn't
> help you, you need a specific compat macro for that struct.

no, SET_MODULE_OWNER is quite intentionally independent of the struct. 
It only requires a consisnent naming in the source, between structures 
that may use the macro.

That's a feature.


> ie. AFAICT it only buys you 2.2 compatibility, and even then only if
> you #define it at the top of your driver.

no, farther back than that, to infinity and beyond :)  The idea of the 
macro is that on earlier kernels, it is simply a no-op, and module 
refcounting is handled by other means.


> I still don't understand: please demonstrate a use in existing source.

demonstrate?  grep for it.  It's used quite a bit.  Removal of 
SET_MODULE_OWNER looks to me to be pointless churn for negative gain. 
If if you wish to pointedly ignore the old-source compatibility angle, 
it is a nice convenience macro.

	Jeff