Re: [PATCHv2 08/11] atomics: switch to generated fallbacks

From: Mark Rutland
Date: Wed Jul 04 2018 - 12:01:55 EST


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?

Thanks,
Mark.