Re: [PATCH] mm, page_pool: introduce a new page type for page pool in page type

[Pavel Begunkov]

On 7/21/25 06:49, Byungchul Park wrote:
> Hi,
>
> I focused on converting the existing APIs accessing ->pp_magic field to
> page type APIs.  However, yes.  Additional works would better be
> considered on top like:
>
>     1. Adjust how to store and retrieve dma index.  Maybe network guys
>        can work better on top.
>
>     2. Move the sanity check for page pool in mm/page_alloc.c to on free.

Don't be in a hurry, I've got a branch, but as mentioned before,
it'll be for-6.18. And there will also be more time for testing.

> This work was inspired by the following link by Pavel:

The idea came from David, let's add

Suggested-by: David Hildenbrand <david@xxxxxxxxxx>

...> -
>   static inline bool netmem_is_pp(netmem_ref netmem)
>   {
> -	return (netmem_get_pp_magic(netmem) & PP_MAGIC_MASK) == PP_SIGNATURE;
> +	if (netmem_is_net_iov(netmem))

This needs to return false for tx niovs. Seems like all callers are
gated on ->pp_recycle, so maybe it's fine, but we can at least
check pp. Mina, you've been checking tx doesn't mix with rx, any
opinion on that?

Question to net maintainers, can a ->pp_recycle marked skb contain
not page pool originated pages or a mix?

--
Pavel Begunkov