Re: [PATCH] mm/ptdesc: Derive from the compound head in page_ptdesc()

[Matthew Wilcox]

On Mon, Nov 10, 2025 at 06:37:25AM +0000, Anshuman Khandual wrote:
> struct ptdesc (including all relevant helpers) support multi order compound
> pages. But page_ptdesc() coverts given page into its own ptdesc rather than
> deriving from its compound head as would have been expected otherwise. Just
> change the macro to fetch the struct ptdesc from the compound head instead,
> so that the same struct ptdesc is reached from all tail pages.

Please review
https://lore.kernel.org/linux-mm/20251020001652.2116669-1-willy@xxxxxxxxxxxxx/
instead.