From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752888AbcGAJRT (ORCPT <rfc822;w@1wt.eu>);
	Fri, 1 Jul 2016 05:17:19 -0400
Received: from mail.skyhub.de ([78.46.96.112]:36810 "EHLO mail.skyhub.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751932AbcGAJRQ (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Fri, 1 Jul 2016 05:17:16 -0400
Date: Fri, 1 Jul 2016 11:17:11 +0200
From: Borislav Petkov <bp@alien8.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= 
	<u.kleine-koenig@pengutronix.de>,
        Franck Bui <fbui@suse.com>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -v2 2/2] printk: Add kernel parameter to control writes
 to /dev/kmsg
Message-ID: <20160701091710.GC4593@pd.tnic>
References: <1467194161-1472-1-git-send-email-bp@alien8.de>
 <1467194161-1472-3-git-send-email-bp@alien8.de>
 <20160701090413.GB27709@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20160701090413.GB27709@gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, Jul 01, 2016 at 11:04:13AM +0200, Ingo Molnar wrote:

...

> So the most robust way to define such bitfields is via a pattern like this:
> 
> enum devkmsg_log_bits {
> 	__DEVKMSG_LOG_BIT_ON,
> 	__DEVKMSG_LOG_BIT_OFF,
> 	__DEVKMSG_LOG_BIT_LOCK,
> };
> 
> enum devkmsg_log_masks {
> 	DEVKMSG_LOG_MASK_ON		= BIT(__DEVKMSG_LOG_BIT_ON),
> 	DEVKMSG_LOG_MASK_OFF		= BIT(__DEVKMSG_LOG_BIT_OFF),
> 	DEVKMSG_LOG_MASK_LOCK		= BIT(__DEVKMSG_LOG_BIT_LOCK),

Agreed with so far, I'd only drop the "_MASK" thing and make it even
easier on the eyes:

enum devkmsg_log_state {
	DEVKMSG_LOG_ON		= BIT(__DEVKMSG_LOG_BIT_ON),
	DEVKMSG_LOG_OFF		= BIT(__DEVKMSG_LOG_BIT_OFF),
	DEVKMSG_LOCK		= BIT(__DEVKMSG_LOG_BIT_LOCK),
};

Now this makes the checking code even more readable!

	if (devkmsg_log & DEVKMSG_LOCK) {

and

	if (devkmsg_log & DEVKMSG_LOG_OFF)

and

	if ((system_state != SYSTEM_BOOTING) && (!(devkmsg_log & DEVKMSG_LOG_ON)) {


And this way you can read it straight-away as english text.

:-)))

Thanks.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.