Re: [RFC PATCH 01/16] mm: add pagechain container for storing multiple pages.

[Kirill A. Shutemov]

On Wed, Sep 02, 2020 at 02:06:13PM -0400, Zi Yan wrote:
> From: Zi Yan <ziy@xxxxxxxxxx>
> 
> When depositing page table pages for 1GB THPs, we need 512 PTE pages +
> 1 PMD page. Instead of counting and depositing 513 pages, we can use the
> PMD page as a leader page and chain the rest 512 PTE pages with ->lru.
> This, however, prevents us depositing PMD pages with ->lru, which is
> currently used by depositing PTE pages for 2MB THPs. So add a new
> pagechain container for PMD pages.
> 
> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>

Just deposit it to a linked list in the mm_struct as we do for PMD if
split ptl disabled.

-- 
 Kirill A. Shutemov