Re: [PATCH mmotm] mm/munlock: mlock_vma_folio() check against VM_SPECIAL

[Matthew Wilcox]

On Thu, Mar 03, 2022 at 09:25:47AM -0800, Hugh Dickins wrote:
> On Thu, 3 Mar 2022, Matthew Wilcox wrote:
> > It looks like it fixes "mm/munlock: mlock_pte_range() when mlocking or
> > munlocking", so I'll fold it into that patch?
> 
> No and yes.
> 
> That's great if you're prepared to move it back before the foliation.
> I think that just involves editing every "folio" to "page", including
> in the title - I very nearly sent it out with mlock_vma_page() in title.

Thanks for the reminder to do the title and changelog ;-)

> But I would prefer it to remain as a separate fix at the end of the
> mm/munlock series: this case is too unusual, and only a "Bad page",
> to mess with bisection prospects; and it's addressing an entirely
> different issue from what the "mlock_pte_range()..." is dealing with.
> Each of them needs its own explanation.
> 
> So I would prefer it as a separate fix about "page"s, on top of the
> mm/munlock series, and you then adjust your foliation commit accordingly.

Done!  Pushed out.

> Thank you: this is what I really wanted, but was afraid to ask of you
> (and of course, other fixes may turn out to be required, too late to
> adjust across the page<->folio barrier in this way: so it's nice to
> be able to do it this way, but rather beyond the call of duty).

Yes, once it's landed in Linus' tree, it's too late to edit, but I'm
willing to insert patches like this.  It's a minor adjustment to my
patch on top of it.