Re: [PATCH] Revert "mm: introduce a new page type for page pool in page type"

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 18 May 2026 12:00:11 +0100 Lorenzo Stoakes <ljs@kernel.org> wrote:

> Maybe worth putting [PATCH mm-hotfixes] just to make it clear this should be an
> urgent hotfix?
> 
> On Fri, May 15, 2026 at 12:47:01PM +0900, Byungchul Park wrote:
> > This reverts commit db359fccf212e7fa3136e6edbed6228475646fd7.
> 
> Maybe 'this reverts commit db359fccf212 ("...") and partially reverts commit
> 735a309b4bfb9e ("...") <details>'?
> 
> >
> > Netpp page_type'ed pages might be used in mapping so as to use
> > @_mapcount.  However, since @page_type and @_mapcount are union'ed in
> > struct page, these two can't be used at the same time.  Revert the
> > commit introducing page_type for Netpp for now.
> 
> Yikes!
> 
> >
> > The patch will be retried once @page_type and @_mapcount get allowed to
> > be used at the same time.
> >
> > The revert also includes removal of @page_type initialization part
> > introduced by commit 735a309b4bfb9e ("net: add net_iov_init() and use it
> > to initialize ->page_type"), which will be restored on the retry.
> 
> As above maybe mentioning at top of commit msg, as right now this reads as a
> pure revert of db359fccf212.

I did

: This reverts commit db359fccf212 ("mm: introduce a new page type for page
: pool in page type") and a part of 735a309b4bfb9e ("net: add net_iov_init()
: and use it > to initialize ->page_type").

> >
> > Reported-by: Dragos Tatulea <dtatulea@nvidia.com>
> > Closes: https://lore.kernel.org/all/982b9bc1-0a0a-4fc5-8e3a-3672db2b29a1@nvidia.com
> 
> Fixes tag?

I assume db359fccf212 ("mm: introduce a new page type for page pool in
page type") is close enough.  Both that and 735a309b4bfb9e are new in
7.1-rcX.