Re: [RFC 4/4] Sparse initialization of struct page array.

[Nathan Zimmer <nzimmer@sgi.com>]

On Fri, Jul 12, 2013 at 09:19:12PM -0700, Yinghai Lu wrote:
> On Thu, Jul 11, 2013 at 7:03 PM, Robin Holt <holt@sgi.com> wrote:
> > +
> >                 page = pfn_to_page(pfn);
> >                 __init_single_page(page, zone, nid, 1);
> > +
> > +               if (pfns > 1)
> > +                       SetPageUninitialized2Mib(page);
> > +
> > +               pfn += pfns;
> >         }
> >  }
> >
> > @@ -6196,6 +6302,7 @@ static const struct trace_print_flags pageflag_names[] = {
> >         {1UL << PG_owner_priv_1,        "owner_priv_1"  },
> >         {1UL << PG_arch_1,              "arch_1"        },
> >         {1UL << PG_reserved,            "reserved"      },
> > +       {1UL << PG_uninitialized2mib,   "Uninit_2MiB"   },
> 
> PG_uninitialized_2m ?
> 
> >         {1UL << PG_private,             "private"       },
> >         {1UL << PG_private_2,           "private_2"     },
> >         {1UL << PG_writeback,           "writeback"     },
> 
> Yinghai


I hadn't actually been very happy with having a PG_uninitialized2mib flag.
It implies if we want to jump to 1Gb pages we would need a second flag,
PG_uninitialized1gb, for that.  I was thinking of changing it to
PG_uninitialized and setting page->private to the correct order.
Thoughts?

Nate