Re: [PATCHv7 RESEND 00/17] mm: Eliminate fake head pages from vmemmap optimization

From: Andrew Morton

Date: Sat Feb 28 2026 - 18:01:44 EST


On Fri, 27 Feb 2026 19:42:38 +0000 "Kiryl Shutsemau (Meta)" <kas@xxxxxxxxxx> wrote:

> This series removes "fake head pages" from the HugeTLB vmemmap
> optimization (HVO) by changing how tail pages encode their relationship
> to the head page.
>
> It simplifies compound_head() and page_ref_add_unless(). Both are in the
> hot path.

This series is unaware of (and incompatible with) Gladyshev's "mm: make
ref_unless functions unless_zero only" cleanup
(https://lkml.kernel.org/r/20260206133328.426921-1-gladyshev.ilya1@xxxxxxxxxxxxxx).

Gladyshev, I'll drop that patch. If you believe that similar changes
after Kiryl's series are desirable, please send them along, thanks.