Re: [RESEND PATCH v1] mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0

[Andrew Morton]

On Fri, 9 Aug 2024 11:41:42 +0200 Uladzislau Rezki <urezki@xxxxxxxxx> wrote:

> > > Acked-by: Barry Song <baohua@xxxxxxxxxx>
> > > 
> > > because we already have a fallback here:
> > > 
> > > void *__vmalloc_node_range_noprof :
> > > 
> > > fail:
> > >         if (shift > PAGE_SHIFT) {
> > >                 shift = PAGE_SHIFT;
> > >                 align = real_align;
> > >                 size = real_size;
> > >                 goto again;
> > >         }
> > 
> > This really deserves a comment because this is not really clear at all.
> > The code is also fragile and it would benefit from some re-org.
> > 
> > Thanks for the fix.
> > 
> > Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> > 
> I agree. This is only clear for people who know the code. A "fallback"
> to order-0 should be commented.

It's been a week.  Could someone please propose a fixup patch to add
this comment?