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From: Rusty Russell <rusty@rustcorp.com.au>
To: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>
Cc: linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
        keescook@chromium.org, casey@schaufler-ca.com, cocci@systeme.lip6.fr,
        "Luis R. Rodriguez" <mcgrof@suse.com>,
        Jani Nikula <jani.nikula@intel.com>,
        Christoph Hellwig <hch@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Hannes Reinecke <hare@suse.de>, Tejun Heo <tj@kernel.org>,
        Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH v1 4/6] moduleparam.h: add module_param_config_*() helpers
In-Reply-To: <1429572637-30234-5-git-send-email-mcgrof@do-not-panic.com>
References: <1429572637-30234-1-git-send-email-mcgrof@do-not-panic.com> <1429572637-30234-5-git-send-email-mcgrof@do-not-panic.com>
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Date: Wed, 22 Apr 2015 16:45:04 +0930
Message-ID: <87mw20ocqv.fsf@rustcorp.com.au>
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"Luis R. Rodriguez" <mcgrof@do-not-panic.com> writes:
> From: "Luis R. Rodriguez" <mcgrof@suse.com>
>
> 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.