Re: [PATCH Resend] mm: Refine __{pgd,p4d,pud,pmd,pte}_alloc_one_*() about HIGHMEM

From: Huacai Chen
Date: Sat Nov 08 2025 - 03:34:35 EST


Hi, Vishal,

On Sat, Nov 8, 2025 at 12:59 AM Vishal Moola (Oracle)
<vishal.moola@xxxxxxxxx> wrote:
>
> On Fri, Nov 07, 2025 at 05:59:22PM +0800, Huacai Chen wrote:
> > __{pgd,p4d,pud,pmd,pte}_alloc_one_*() always allocate pages with GFP
> > flag GFP_PGTABLE_KERNEL/GFP_PGTABLE_USER. These two macros are defined
> > as follows:
> >
> > #define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO)
> > #define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)
> >
> > There is no __GFP_HIGHMEM in them, so we needn't to clear __GFP_HIGHMEM
> > explicitly.
> >
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
>
> I'm not really sure what "Refine ... about HIGHMEM" is supposed to mean.
> Might it be clearer to title this something like "Remove unnecessary
> highmem in ..."?
Yes, that is better, but Andrew has picked this patch, should I resend
a new version?

Huacai