Subject: Re: [PATCH net-next v11 05/13] page_pool: convert to use netmem

From: Jakub Kicinski <[email-masked]>
Date: Wed, 12 Jun 2024 17:10:29 -0700

On Fri,  7 Jun 2024 00:51:15 +0000 Mina Almasry wrote:
> Abstrace the memory type from the page_pool so we can later add support
> for new memory types. Convert the page_pool to use the new netmem type
> abstraction, rather than use struct page directly.
> 
> As of this patch the netmem type is a no-op abstraction: it's always a
> struct page underneath. All the page pool internals are converted to
> use struct netmem instead of struct page, and the page pool now exports
> 2 APIs:
> 
> 1. The existing struct page API.
> 2. The new struct netmem API.
> 
> Keeping the existing API is transitional; we do not want to refactor all
> the current drivers using the page pool at once.
> 
> The netmem abstraction is currently a no-op. The page_pool uses
> page_to_netmem() to convert allocated pages to netmem, and uses
> netmem_to_page() to convert the netmem back to pages to pass to mm APIs,
> 
> Follow up patches to this series add non-paged netmem support to the
> page_pool. This change is factored out on its own to limit the code
> churn to this 1 patch, for ease of code review.

Sorry for lack of meaningful review, busy times, in the meantime:

drivers/net/ethernet/renesas/ravb_main.c:306:16: error: incompatible integer to pointer conversion assigning to 'struct page *' from 'netmem_ref' (aka 'unsigned long') [-Wint-conversion]
  306 |         rx_buff->page = page_pool_alloc(priv->rx_pool[q], &rx_buff->offset,
      |                       ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  307 |                                         &size, gfp_mask);
      |                                         ~~~~~~~~~~~~~~~~
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