Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.

Greg KH
2024-03-05T22:32:59Z

On Tue, Mar 05, 2024 at 11:09:17PM +0100, David Hildenbrand wrote:
> On 05.03.24 23:04, Greg KH wrote:
> > On Tue, Mar 05, 2024 at 11:13:13AM -0500, Zi Yan wrote:
> > > From: Zi Yan <ziy@nvidia.com>
> > >
> > > The tail pages in a THP can have swap entry information stored in their
> > > private field. When migrating to a new page, all tail pages of the new
> > > page need to update ->private to avoid future data corruption.
> > >
> > > Signed-off-by: Zi Yan <ziy@nvidia.com>
> > > ---
> > > mm/migrate.c | 6 +++++-
> > > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > What is the git commit id of this change in Linus's tree?
>
> Unfortunately, we had to do stable-only versions, because the backport
> of the "accidental" fix that removes the per-subpage "private" information
> would be non-trivial, especially for pre-folio-converison times.
>
> The accidental fix is
>
> 07e09c483cbef2a252f75d95670755a0607288f5

None of that is obvious at all here, we need loads of documentation in
the changelog text that says all of that please.

thanks,

greg k-h