Re: [RFC PATCH 7/8] mm/vmalloc: Coalesce same page_shift mappings in vmap to avoid pgtable zigzag

Barry Song
2026-04-08T21:58:44Z

On Wed, Apr 8, 2026 at 7:36 PM Dev Jain <dev.jain@arm.com> wrote:
>
>
>
> On 08/04/26 8:21 am, Barry Song (Xiaomi) wrote:
> > For vmap(), detect pages with the same page_shift and map them in
> > batches, avoiding the pgtable zigzag caused by per-page mapping.
> >
> > Signed-off-by: Barry Song (Xiaomi) <baohua@kernel.org>
> > ---
>
> In patch 4, you eliminate the pagetable rewalk, and in patch 5,
> you re-introduce it, then in this patch you eliminate it again.
> So please just squash this into #5.
>

Sure. I guess I revealed some of the development process in this
patchset. The patch was initially written with page table rewalks
for simplicity and then iteratively improved. I agree that nobody
really cares how it was originally written :-)

Best Regards
Barry