Re: [PATCH v1 4/6] moduleparam.h: add module_param_config_*() helpers

From: Rusty Russell
Date: Wed Apr 22 2015 - 04:11:19 EST


"Luis R. Rodriguez" <mcgrof@xxxxxxxxxxxxxxxx> writes:
> From: "Luis R. Rodriguez" <mcgrof@xxxxxxxx>
>
> This adds a couple of bool module_param_config_*() helpers
> which are designed to let us easily associate a booloean
> module parameter with an associated kernel configuration
> option, and to help us remove #ifdef'ery eyesores.

But they don't. And I had to read the descriptions twice to understand
what you're doing.

eg you use it like this:

-#ifdef CONFIG_WQ_POWER_EFFICIENT_DEFAULT
-static bool wq_power_efficient = true;
-#else
-static bool wq_power_efficient;
-#endif
-
-module_param_named(power_efficient, wq_power_efficient, bool, 0444);
+module_param_config_on_off(power_efficient, wq_power_efficient, 0444,
CONFIG_WQ_POWER_EFFICIENT_DEFAULT);

It would be much clearer to do this:

-#ifdef CONFIG_WQ_POWER_EFFICIENT_DEFAULT
-static bool wq_power_efficient = true;
-#else
-static bool wq_power_efficient;
-#endif
+static bool wq_power_efficient = IS_ENABLED(CONFIG_WQ_POWER_EFFICIENT_DEFAULT);

I know exactly what that does without having to notice the difference
between module_param_config_on_off() and module_param_config_on().

Cheers,
Rusty.
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