Re: [PATCH v2 1/2] mm/page_alloc: Do not calculate node's total pages and memmap pages when empty

Muchun Song
2022-06-22T08:54:53Z

On Wed, Jun 22, 2022 at 10:31:12AM +0200, David Hildenbrand wrote:
> On 22.06.22 05:56, Muchun Song wrote:
> > On Wed, Jun 22, 2022 at 05:47:22AM +0200, Oscar Salvador wrote:
> >> On Tue, Jun 21, 2022 at 09:44:47AM +0200, David Hildenbrand wrote:
> >>>
> >>>
> >>> It's worth noting that the check in pgdat_is_empty() is slightly
> >>> different. I *think* it doesn't matter in practice, yet I wonder if we
> >>> should simply fixup (currently unused) pgdat_is_empty().
> >>
> >> I guess we could change it to
> >>
> >> static inline bool pgdat_is_empty(pg_data_t *pgdat)
> >> {
> >> return node_start_pfn(pgdat->node_id) == node_end_pfn(pgdat->node_id)
> >> }
> >>
> >> ? And maybe even rename it to to node_is_empty (not sure why but I tend to like
> >
> > At least I like this name (node_is_empty) as well.
> >
>
> Let's try keeping it consistent. I think node_is_empty() might indicate
> that we're punching in a node id instead of a pgdat.
>

I suspect Oscar will change the argument to "nid" as well, like:

static inline bool node_is_empty(int nid)
{
return node_start_pfn(nid) == node_end_pfn(nid);
}

Does this look good?

Thanks.

>
> --
> Thanks,
>
> David / dhildenb
>
>