[PATCH v2 7/7] mm/vmalloc: Stop scanning for compound pages after encountering small pages in vmap

[Wen Jiang]

Sure, will do.

Thanks,
Wen Jiang

On Wed, 20 May 2026 at 17:44, Uladzislau Rezki <urezki at gmail.com> wrote:
>
> On Thu, May 14, 2026 at 05:41:08PM +0800, Wen Jiang wrote:
> > From: "Barry Song (Xiaomi)" <baohua at kernel.org>
> >
> > Users typically allocate memory in descending orders, e.g.
> > 8 → 4 → 0. Once an order-0 page is encountered, subsequent
> > pages are likely to also be order-0, so we stop scanning
> > for compound pages at that point.
> >
> > Signed-off-by: Barry Song (Xiaomi) <baohua at kernel.org>
> > Signed-off-by: Wen Jiang <jiangwen6 at xiaomi.com>
> > Tested-by: Xueyuan Chen <xueyuan.chen21 at gmail.com>
> > ---
> >  mm/vmalloc.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index b3389c8f1..60579bfbf 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -3576,6 +3576,12 @@ static int __vmap_huge(unsigned long addr, unsigned long end,
> >                       map_addr = addr;
> >                       idx = i;
> >               }
> > +             /*
> > +              * Once small pages are encountered, the remaining pages
> > +              * are likely small as well
> > +              */
> > +             if (shift == PAGE_SHIFT)
> > +                     break;
> >
> >               addr += 1UL << shift;
> >               i += 1U << (shift - PAGE_SHIFT);
> > --
> > 2.34.1
> >
> Can we squash this patch with
> "mm/vmalloc: map contiguous pages in batches for vmap() if possible"?
>
> --
> Uladzislau Rezki