Re: [RFC V1 PATCH mm-hotfixes 2/3] x86/mm: define p*d_populate_kernel() and top-level page table sync

Harry Yoo
2025-07-11T04:02:56Z

On Thu, Jul 10, 2025 at 05:27:36PM +0900, Harry Yoo wrote:
> On Wed, Jul 09, 2025 at 02:13:59PM -0700, Andrew Morton wrote:
> > On Wed, 9 Jul 2025 22:16:56 +0900 Harry Yoo <harry.yoo@oracle.com> wrote:
> >
> > > Fixes: 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps")
> > > Fixes: faf1c0008a33 ("x86/vmemmap: optimize for consecutive sections in partial populated PMDs")
> >
> > Fortunately both of these appeared in 6.9-rc7, which minimizes the
> > problem with having more than one Fixes:.
> >
> > But still, the Fixes: is a pointer telling -stable maintainers where in
> > the kernel history we want them to insert the patch(es). Giving them
> > multiple insertions points is confusing! Can we narrow this down
> > to a single Fixes:?
>
> If I had to choose only one I think it should be 4917f55b4ef9,
> since faf1c0008a33 is not yet known to be triggered without enlarging
> struct page (and once it's backported it fixes both of them).

On second look, faf1c0008a33 is introduced in v5.13-rc1 and
4917f55b4ef9 is introduced in v5.19-rc1.

I'll go with Fixes: faf1c0008a33 because it's introduced earlier.

> Will update in the next version.
>
> --
> Cheers,
> Harry / Hyeonggon