From: Joe Perches <joe@perches.com>
To: Mark Brown <broonie@kernel.org>, Paul Kocialkowski <contact@paulk.fr>
Cc: Liam Girdwood <lgirdwood@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] regulator: core: Use a bitfield for continuous_voltage_range
Date: Fri, 22 Jan 2016 11:15:28 -0800 [thread overview]
Message-ID: <1453490128.13870.31.camel@perches.com> (raw)
In-Reply-To: <1453407851-8039-1-git-send-email-broonie@kernel.org>
On Thu, 2016-01-21 at 20:24 +0000, Mark Brown wrote:
> Using a bitfield enables the compiler to lay out the structure more
> efficiently when we have other boolean flags since multiple values can
> be included in a single byte.
>
> Signed-off-by: Mark Brown <broonie@kernel.org>
> ---
> include/linux/regulator/driver.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
> index 16ac9e108806..3ac0f306f033 100644
> --- a/include/linux/regulator/driver.h
> +++ b/include/linux/regulator/driver.h
> @@ -281,7 +281,7 @@ struct regulator_desc {
> const struct regulator_desc *,
> struct regulator_config *);
> int id;
> - 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.
> unsigned n_voltages;
> const struct regulator_ops *ops;
> int irq;
next prev parent reply other threads:[~2016-01-22 19:15 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-21 20:24 [PATCH 1/2] regulator: core: Use a bitfield for continuous_voltage_range Mark Brown
2016-01-21 20:24 ` [PATCH 2/2] regulator: core: Provide per-regulator runtime PM support Mark Brown
2016-01-21 21:49 ` kbuild test robot
2016-01-29 12:02 ` Paul Kocialkowski
2016-02-09 20:51 ` Paul Kocialkowski
2016-02-12 19:24 ` Paul Kocialkowski
2016-02-26 2:13 ` Mark Brown
2016-01-22 19:15 ` Joe Perches [this message]
2016-01-22 21:31 ` [PATCH 1/2] regulator: core: Use a bitfield for continuous_voltage_range Mark Brown
2016-01-22 21:42 ` Joe Perches
2016-01-23 15:16 ` Mark Brown
2016-04-21 16:11 ` Applied "regulator: core: Use a bitfield for continuous_voltage_range" to the regulator tree Mark Brown
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