Re: [PATCH v1 06/11] mm: support GUP-triggered unsharing via FAULT_FLAG_UNSHARE (!hugetlb)

[Linus Torvalds]

On Mon, Dec 20, 2021 at 1:02 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
>
> Hah, that was actually how I did it originally (without actually
> committing at each step, and with a few "Oh, hang on, now we can avoid
> calculating this too" stops and restarts along the way), but I thought
> it all hung together logically as a single change.  It's hard to see
> things from the other person's perspective at times.

In just about any other area, I wouldn't mind one bigger patch that
just removes code that isn't used.

But when it's in the vm code, and it's pretty grotty, I do prefer
seeing three patches that individually are much easier to see that
"yeah, this doesn't actually change anything at all".

The combined patch may be exactly the same thing, it's just much
harder to see that "oh, now it's not used any more".

That was perhaps especially true since a number of the changes also
ended up doing statement simplification when the old layout made no
sense any more with part of the results not used.

So your 3-patch series was much easier to look at and go "Yeah, I
believe each of these patches is a no-op".

So ACK on all those patches.

          Linus