Re: [PATCH 2/8] param: use ops in struct kernel_param, rather than get and set fns directly

From: Rusty Russell
Date: Fri Oct 30 2009 - 07:13:49 EST


On Fri, 30 Oct 2009 08:48:12 pm Takashi Iwai wrote:
> At Fri, 23 Oct 2009 00:51:28 +1030,
> Rusty Russell wrote:
> >
> > This is more kernel-ish, saves some space, and also allows us to
> > expand the ops without breaking all the callers who are happy for the
> > new members to be NULL.
> >
> > The few places which defined their own param types are changed to the
> > new scheme.
> >
> > Since we're touching them anyway, we change get and set to take a
> > const struct kernel_param (which they were, and will be again).
> >
> > To reduce churn, module_param_call creates the ops struct so the callers
> > don't have to change (and casts the functions to reduce warnings).
> > The modern version which takes an ops struct is called module_param_cb.
>
> This is nice, as it also reduces the size of struct kernel_param, so
> each parameter uses less footprint (who cares, though?) :)
>
> But, just wondering whether we still need to export get/set
> functions. They can be called from ops now, so if any, it can be
> defined even as an inlinefunction or a macro.

My thought too, so I tried that, but many are still used like so:

module_param_call(foo, set_foo, param_get_uint, NULL, 0644);

They can all be replaced in time with something like:
static int param_get_foo(char *buffer, const struct kernel_param *kp)
{
return param_ops_uint.get(buffer, kp);
}

But it'll take a transition period.

Thanks!
Rusty.



>
>
> thanks,
>
> Takashi
>
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