Re: [RFC mm v4 1/2] page_pool: check if nmdesc->pp is !NULL to confirm its usage as pp for net_iov

[Jakub Kicinski]

On Thu, 23 Oct 2025 16:44:09 +0900 Byungchul Park wrote:
> As a preparation, the check for net_iov, that is not page-backed, should
> avoid using ->pp_magic since net_iov doens't have to do with page type.

doesn't

> Instead, nmdesc->pp can be used if a net_iov or its nmdesc belongs to a
> page pool, by making sure nmdesc->pp is NULL otherwise.

Please explain in the commit message why the new branch in
netmem_is_pp() is necessary. We used to identify the pages based
on PP_SIGNATURE, now we identify them based on page_type.