Re: [PATCH v1 1/1] mm: report per-page metadata information

Matthew Wilcox
2023-09-14T12:48:45Z

On Wed, Sep 13, 2023 at 11:51:25PM +0300, Mike Rapoport wrote:
> > @@ -387,8 +390,12 @@ static int alloc_vmemmap_page_list(unsigned long start, unsigned long end,
> >
> > while (nr_pages--) {
> > page = alloc_pages_node(nid, gfp_mask, 0);
> > - if (!page)
> > + if (!page) {
> > goto out;
> > + } else {
> > + __mod_node_page_state(NODE_DATA(page_to_nid(page)),
> > + NR_PAGE_METADATA, 1);
>
> We can update this once for nr_pages outside the loop, cannot we?

Except that nr_pages is being used as the loop counter.
Probably best to turn this into a normal (i = 0; i < nr_pages; i++)
loop, and then we can do as you say. But this isn't a particularly
interesting high-performance loop.