Re: [External] Re: [PATCH v4 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one

[Muchun Song]

On Wed, Jan 13, 2021 at 6:57 PM Oscar Salvador <osalvador@xxxxxxx> wrote:
>
> On Wed, Jan 13, 2021 at 01:22:04PM +0800, Muchun Song wrote:
> > diff --git a/mm/migrate.c b/mm/migrate.c
> > index 4385f2fb5d18..a6631c4eb6a6 100644
> > --- a/mm/migrate.c
> > +++ b/mm/migrate.c
> > @@ -1279,6 +1279,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
> >               return -ENOSYS;
> >       }
> >
> > +     if (page_count(hpage) == 1) {
> > +             /* page was freed from under us. So we are done. */
> > +             putback_active_hugepage(hpage);
> > +             return MIGRATEPAGE_SUCCESS;
> > +     }
> > +
>
> I was a bit puzzled as why we did not go to the "goto" block that already does
> this, but then I saw the put_new_page/new_hpage handlind further down.
> It could be re-arranged but out of scope, so:

Agree. I also thought about this. :)

>
> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
>

Thanks.

>
> --
> Oscar Salvador
> SUSE L3