Re: [PATCH 2/8] param: use ops in struct kernel_param, rather than get and set fns directly
From: Takashi Iwai
Date: Sun Nov 01 2009 - 05:26:48 EST
At Fri, 30 Oct 2009 21:43:39 +1030,
Rusty Russell wrote:
> 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.
Fair enough. And, maybe these get/set should be defined as an ops
explicitly so that it can be used for multiple parameters. But we
can do cleanups later, of course :)
Oh, in case you need,
Reviewed-by: Takashi Iwai <tiwai@xxxxxxx>
for all new patches.
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