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Date: Sun, 16 Jun 2013 23:36:44 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH qom-cpu v2 24/29] cpu: Drop
 qemu_for_each_cpu()
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: Andreas =?iso-8859-1?Q?F=E4rber?= <afaerber@suse.de>, qemu-devel@nongnu.org

On Sun, Jun 16, 2013 at 09:30:29PM +0100, Peter Maydell wrote:
> On 16 June 2013 21:26, Michael S. Tsirkin <mst@redhat.com> wrote:
> > On Sun, Jun 16, 2013 at 05:57:44PM +0200, Andreas F=E4rber wrote:
> >> Revert commit d6b9e0d60cc511eca210834428bb74508cff3d33 (cpu: Add
> >> qemu_for_each_cpu()) and its usage in favor of open-coding CPU loops=
,
> >> now that they are based on CPUState.
> >>
> >> Suggested-by: Markus Armbruster <armbru@redhat.com>
> >> Signed-off-by: Andreas F=E4rber <afaerber@suse.de>
> >
> > Open-coding is kind of nasty though.
> >
> > How about
> > #define qemu_for_each_cpu(cpu) \
> >     for (cpu =3D first_cpu; cpu !=3D NULL; cpu =3D cpu->next_cpu)
>=20
> Personally for an iteration that simple I would prefer
> the opencoded version -- it's more immediately
> obvious what it's doing and that it's not doing anything
> weird.

Only if you have memorized how is the list of CPUs put together.
You probably did, most other readers probably didn't,
and have to waste time looking it up.

> Precedent isn't everything, but a quick grep for 'foreach'
> and 'for_each' suggests that we generally use the callback-fn
> style rather than iterator macros.
>=20
> thanks
> -- PMM

Callback is fine too.

--=20
MST