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Date:   Wed, 4 Jul 2018 18:44:52 +0100
From:   Will Deacon <will.deacon@arm.com>
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     linux-kernel@vger.kernel.org, peterz@infradead.org,
        boqun.feng@gmail.com
Subject: Re: [PATCHv2 08/11] atomics: switch to generated fallbacks
Message-ID: <20180704174451.GE9668@arm.com>
References: <20180625105952.3756-1-mark.rutland@arm.com>
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 <20180704152846.GL4828@arm.com>
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On Wed, Jul 04, 2018 at 05:01:46PM +0100, Mark Rutland wrote:
> On Wed, Jul 04, 2018 at 04:28:47PM +0100, Will Deacon wrote:
> > On Mon, Jun 25, 2018 at 11:59:49AM +0100, Mark Rutland wrote:
> > > As a step to ensuring the atomic* APIs are consistent, switch to fallbacks
> > > generated by gen-atomic-fallback.sh.
> > > 
> > > These are checked in rather than generated with Kbuild, since:
> > > 
> > > * This allows inspection of the atomics with git grep and ctags on a
> > >   pristine tree, which Linus strongly prefers being able to do.
> > > 
> > > * The fallbacks are not expected to change very often, and are not
> > >   affected by machine details or configuration options, so regenerating
> > >   them for *every* build is somewhat wasteful.
> > > 
> > > * These are included by files required *very* early in the build process
> > >   (e.g. for generating bounds.h), and we'd rather not complicate the
> > >   top-level Kbuild file.
> > 
> > Would it be worth checking that the generated output from the script doesn't
> > differ from the file in tree at some point during the build, and issuing a
> > warning if they do?
> 
> We could do that in the top-level Kbuild file. It would be less hideous
> than the generation was, since we don't have to add dependencies to all
> other targets.
> 
> I can take a look, if you'd like?

Yes, please. Might also be worth having your "THIS FILE IS GENERATED"
disclaimer before each function, as I completely missed it when I opened the
file since it just looks like part of the license and jumping around with
ctags might dump you halfway down the file.

Will