Re: [PATCH v4 16/21] mm/mm_init: simplify deferred_free_pages() migratetype init

[Andrew Morton]

On Sun, 26 Jul 2026 13:16:54 +0300 Mike Rapoport <rppt@xxxxxxxxxx> wrote:

> On Sat, Jul 25, 2026 at 07:21:16PM +0200, Pratyush Yadav wrote:
> > From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> > 
> > deferred_free_pages() open-codes two loops to initialize the pageblock
> > migratetype for a range of pages.
> > 
> > Replace them with pageblock_migratetype_init_range() to remove the
> > duplication and make the code clearer (Note that deferred_free_pages() may
> > be called from atomic context).
> > 
> > Link: https://lore.kernel.org/20260612035903.2468601-6-songmuchun@xxxxxxxxxxxxx
> > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> > Acked-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> > Acked-by: Oscar Salvador <osalvador@xxxxxxx>
> > Signed-off-by: Pratyush Yadav (Google) <pratyush@xxxxxxxxxx>
> > ---
> > 
> > Notes:
> >     This patch is taken from Muchun's series [0]. The patch as of today is
> >     in mm-unstable.
> 
> @Andrew,
> 
> It looks like it'll take some time for this patch to get into mm-stable so
> we can't base this work on a branch in the mm tree :(

I didn't know anyone was using mm-stable :(

Series is adequately reviewed and is near head-of-queue so I can move
it into mm-stable a few days hence if that helps?

> I'd like to expose the KHO scratch extension to linux-next ASAP so I'm
> inclined to take this patch as a part of this series and live for a while
> with a duplicated commit in linux-next. Once this patch would be in
> mm-stable we can rebase kho-scratch work on top of mm-stable and hopefully
> there will be enough time for it to live in linux-next so that Linus won't
> get angry at us :) 
> 
> How does that sound to you?

That's fine - let me know what you choose to do and I'll adapt to it.

An unknown (to me) is whether Muchun's series "mm: Refactor bootmem
gigantic hugepage allocation, v4" still works with this patch removed.  Everything
applies OK for what that's worth.