Re: [PATCH -next 005/491] ARM/UNIPHIER ARCHITECTURE: Use fallthrough;

From: Joe Perches
Date: Thu Mar 12 2020 - 10:17:10 EST


On Thu, 2020-03-12 at 09:47 -0400, Theodore Y. Ts'o wrote:
> On Thu, Mar 12, 2020 at 02:37:31AM -0700, Joe Perches wrote:
> > As I have suggested a few times, better still
> > would be to have a mechanism for scripted patches
> > applied possibly as single treewide patch.
> >
> > Likely applied only at an -rc1.
> >
> > The stated negatives to a treewide mechanism
> > have been difficulty to backport to -stable.
>
> Any time we do a massive, disruptive change to the code base, it's
> going to cause problems to -stable. It means that bug fix patches
> won't necessarily auto-apply, and some will require manual fixups
> afterwards

That's mostly a tools problem than a real problem.

> Given that this change doesn't really fix any bugs, I'd have to ask
> the question --- is it *worth* it? We really need to apply a certain
> amount of cost/benefit analysis around this.
>
> If it were really important, the thing we could do is to apply a
> single treewide patch at some point after the merge window. I'd
> suggest after -rc2, myself, but reasonable people can differ. And
> then, if it were *really* important we could run the same script on
> the stable kernels.
>
> But for changing "/* fallthrough */" to "fallthrough;"
>
> Does this ***really*** matter?

That depends a bit on whether clang is your
compiler of choice.

> Why are we tying ourselves up in knots
> trying to do this all at once?

Discretely or treewide, all at once or done over time,
the impact problem to backports is the same.