linux-kernel - Re: [PATCH 1/2] regulator: core: Use a bitfield for continuous_voltage

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Message-ID: <1453498953.13870.41.camel@perches.com>
Date:	Fri, 22 Jan 2016 13:42:33 -0800
From:	Joe Perches <joe@...ches.com>
To:	Mark Brown <broonie@...nel.org>
Cc:	Paul Kocialkowski <contact@...lk.fr>,
	Liam Girdwood <lgirdwood@...il.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] regulator: core: Use a bitfield for
 continuous_voltage_range

On Fri, 2016-01-22 at 21:31 +0000, Mark Brown wrote:
> On Fri, Jan 22, 2016 at 11:15:28AM -0800, Joe Perches wrote:
> > On Thu, 2016-01-21 at 20:24 +0000, Mark Brown wrote:
> 
> > > -	bool continuous_voltage_range;
> > > +	unsigned int continuous_voltage_range:1;
> 
> > Is this really valuable?
> 
> > There are already padding bytes that are unused
> > and adding a couple more bools would be space
> > cost-free and more readable.
> 
> > I believe that read/write of bytes is also more
> > efficient on some architectures than bit field
> > read/modify/write uses.
> 
> It adds up when you get more flags and these are not in the least bit
> performance sensitive.

Sure, but intelligibility is useful too.
Do you expect to have more than 4 of these flags?