Re: [PATCH 4/5] fs/proc/page: use a folio in stable_page_flags()

[Kefeng Wang]

On 2023/11/3 20:28, Matthew Wilcox wrote:
> On Fri, Nov 03, 2023 at 03:29:05PM +0800, Kefeng Wang wrote:
> > Replace ten compound_head() calls with one page_folio().
>
> This is going to conflict with Gregory Price's work:
>
> https://lore.kernel.org/linux-mm/ZUCD1dsbrFjdZgVv@xxxxxxxxxxxx/
>
> Perhaps the two of you can collaborate on a patch series?

Will check this patch.

> >   	u |= kpf_copy_bit(k, KPF_SLAB,		PG_slab);
> > -	if (PageTail(page) && PageSlab(page))
> > +	if (PageTail(page) && folio_test_slab(folio))
> >   		u |= 1 << KPF_SLAB;
>
> This doesn't make sense ...

Yes, after commit dcb351cd095a ("page-flags: define behavior SL*B-
related flags on compound pages"), the slab could not be a tail,
I will drop this line.