netdev - Re: [PATCH] bluetooth.h: __ variants of u8 and friends are not neccessary inside kernel

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Date:   Thu, 6 Oct 2016 11:38:04 +0300
From:   Johan Hedberg <johan.hedberg@...il.com>
To:     Joe Perches <joe@...ches.com>
Cc:     Pavel Machek <pavel@....cz>, Marcel Holtmann <marcel@...tmann.org>,
        "Gustavo F. Padovan" <gustavo@...ovan.org>,
        "David S. Miller" <davem@...emloft.net>,
        linux-bluetooth@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] bluetooth.h: __ variants of u8 and friends are not
 neccessary inside kernel

Hi,

On Thu, Oct 06, 2016, Joe Perches wrote:
> On Thu, 2016-10-06 at 09:02 +0200, Pavel Machek wrote:
> > I believe you are wrong. bit addressability does not matter, cpu can
> > definitely get the bit values.
> > 
> > u8 foo:1;
> > u8 bar:1;
> > u8 baz:1;
> > 
> > should take 1 byte, where
> > 
> > bool foo, bar, baz;
> > 
> > will take more like 3.
> 
> Definitely true.
> 
> There is only one single bitfield foo here though
> so what you wrote doesn't apply.

What's in the tree is a left-over from times when there were multiple
bit fields in this struct. By the time others were removed and there was
only one left no-one has apparently bothered to update it to a bool or
single u8.

Johan