Re: [RFC PATCH 3/6] mm: page_owner: add support for splitting to any order in split page_owner.

On Wed, Nov 11, 2020 at 03:40:05PM -0500, Zi Yan wrote:

• for (i = 0; i < nr; i++) {

• for (i = 0; i < nr; i += (1 << new_order)) { page_owner = get_page_owner(page_ext);

• page_owner->order = 0;
  

• page_owner->order = new_order;
  

  page_ext = page_ext_next(page_ext); }

This doesn't do what you're hoping it will. It's going to set ->order to new_order for the first N pages instead of every 1/N pages.

You'll need to do something like

page_ext = lookup_page_ext(page + i);

or add a new page_ext_add(page_ext, 1 << new_order);