Re: [PATCH] ARC: Enable machine_desc->init_per_cpu for non-SMP configs

From: Alexey Brodkin
Date: Thu Jun 14 2018 - 18:26:25 EST

Hi Vineet,

On Thu, 2017-11-30 at 09:46 -0800, Vineet Gupta wrote:
> On 11/29/2017 12:21 AM, Alexey Brodkin wrote:
> > As of today we assumed that "machine_desc->init_per_cpu" calls
> > are only usable on SMP systems when we want to run some piece of
> > code on early boot for each and every core, I guess assumption was
> > we have "machine_desc->init_early" for single-core cases where
> > the one and only master core can do all the things.
> >
> > But it turned out for platforms which might be both UP and SMP it
> > might be benificial to use "init_per_cpu" for both UP and SMP cases
> > with which we achieve 2 things simultaneously:
> > 1) Exactly the same one code will be used for UP&SMP for
> > things required to be done on each an every core regardless if it's
> > a master and the only core in UP system or any other slave core in SMP
> > setup.
> > 1) There will be no "ifdef CONFIG_SMP" around "init_per_cpu".
> >
> Seems fine to me. However this needs to go with the actual platform change which
> needs it.

Well for example this might get in the way of building kernel for HSDK with
CONFIG_SMP disabled which is IMHO quite valid case in terms of testing
code-base compiled with no CONFIG_SMP (something Waldemar was up to).

Is it a strong enough reason for that patch to be applied?