From: Matthew Wilcox <willy@infradead.org>
To: Byungchul Park <byungchul@sk.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, kernel_team@skhynix.com, kuba@kernel.org,
almasrymina@google.com, ilias.apalodimas@linaro.org,
harry.yoo@oracle.com, hawk@kernel.org, akpm@linux-foundation.org,
ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net,
john.fastabend@gmail.com, andrew+netdev@lunn.ch,
edumazet@google.com, pabeni@redhat.com, vishal.moola@gmail.com
Subject: Re: [RFC 19/19] mm, netmem: remove the page pool members in struct page
Date: Mon, 12 May 2025 15:42:54 +0100 [thread overview]
Message-ID: <aCII7vd3C2gB0oi_@casper.infradead.org> (raw)
In-Reply-To: <20250512125103.GC45370@system.software.com>
On Mon, May 12, 2025 at 09:51:03PM +0900, Byungchul Park wrote:
> On Fri, May 09, 2025 at 07:02:30PM +0100, Matthew Wilcox wrote:
> > > + struct __netmem_desc place_holder_1; /* for page pool */
> > > struct { /* Tail pages of compound page */
> > > unsigned long compound_head; /* Bit zero is set */
> > > };
> >
> > The include and the place holder aren't needed.
>
> Or netmem_desc overlaying struct page might be conflict with other
> fields of sturct page e.g. _mapcount, _refcount and the like, once the
> layout of struct page *extremly changes* in the future before
> netmem_desc has its own instance.
That's not how it'll happen. When the layout of struct page changes,
it'll shrink substantially (cut in half). That means that dynamically
allocating netmem_desc must happen first (along with slab, folio, etc,
etc).
next prev parent reply other threads:[~2025-05-12 14:43 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-09 11:51 [RFC 00/19] Split netmem from struct page Byungchul Park
2025-05-09 11:51 ` [RFC 01/19] netmem: rename struct net_iov to struct netmem_desc Byungchul Park
2025-05-12 13:11 ` Pavel Begunkov
2025-05-12 13:29 ` Byungchul Park
2025-05-12 19:14 ` Mina Almasry
2025-05-13 2:00 ` Byungchul Park
2025-05-13 12:58 ` Pavel Begunkov
2025-05-13 12:49 ` Pavel Begunkov
2025-05-14 0:07 ` Byungchul Park
2025-05-09 11:51 ` [RFC 02/19] netmem: introduce netmem alloc/put API to wrap page alloc/put API Byungchul Park
2025-05-09 13:39 ` Mina Almasry
2025-05-09 14:08 ` Mina Almasry
2025-05-12 12:30 ` Byungchul Park
2025-05-09 11:51 ` [RFC 03/19] page_pool: use netmem alloc/put API in __page_pool_alloc_page_order() Byungchul Park
2025-05-09 11:51 ` [RFC 04/19] page_pool: rename __page_pool_alloc_page_order() to __page_pool_alloc_large_netmem() Byungchul Park
2025-05-09 11:51 ` [RFC 05/19] page_pool: use netmem alloc/put API in __page_pool_alloc_pages_slow() Byungchul Park
2025-05-09 11:51 ` [RFC 06/19] page_pool: rename page_pool_return_page() to page_pool_return_netmem() Byungchul Park
2025-05-09 11:51 ` [RFC 07/19] page_pool: use netmem alloc/put API in page_pool_return_netmem() Byungchul Park
2025-05-09 11:51 ` [RFC 08/19] page_pool: rename __page_pool_release_page_dma() to __page_pool_release_netmem_dma() Byungchul Park
2025-05-09 11:51 ` [RFC 09/19] page_pool: rename __page_pool_put_page() to __page_pool_put_netmem() Byungchul Park
2025-05-09 11:51 ` [RFC 10/19] page_pool: rename __page_pool_alloc_pages_slow() to __page_pool_alloc_netmems_slow() Byungchul Park
2025-05-09 11:51 ` [RFC 11/19] mlx4: use netmem descriptor and API for page pool Byungchul Park
2025-05-09 11:51 ` [RFC 12/19] netmem: introduce page_pool_recycle_direct_netmem() Byungchul Park
2025-05-09 11:51 ` [RFC 13/19] page_pool: expand scope of is_pp_{netmem,page}() to global Byungchul Park
2025-05-12 12:46 ` Toke Høiland-Jørgensen
2025-05-12 12:55 ` Byungchul Park
2025-05-14 3:00 ` Byungchul Park
2025-05-14 11:17 ` Toke Høiland-Jørgensen
2025-05-09 11:51 ` [RFC 14/19] mm: page_alloc: do not directly access page->pp_magic but use is_pp_page() Byungchul Park
2025-05-09 11:51 ` [RFC 15/19] mlx5: use netmem descriptor and API for page pool Byungchul Park
2025-05-09 11:51 ` [RFC 16/19] netmem: use _Generic to cover const casting for page_to_netmem() Byungchul Park
2025-05-09 11:51 ` [RFC 17/19] netmem: remove __netmem_get_pp() Byungchul Park
2025-05-09 13:47 ` Mina Almasry
2025-05-09 11:51 ` [RFC 18/19] page_pool: make page_pool_get_dma_addr() just wrap page_pool_get_dma_addr_netmem() Byungchul Park
2025-05-09 13:49 ` Mina Almasry
2025-05-10 7:28 ` Ilias Apalodimas
2025-05-09 11:51 ` [RFC 19/19] mm, netmem: remove the page pool members in struct page Byungchul Park
2025-05-09 17:32 ` Mina Almasry
2025-05-09 18:11 ` Matthew Wilcox
2025-05-09 19:04 ` Mina Almasry
2025-05-09 19:48 ` Matthew Wilcox
2025-05-12 19:10 ` Mina Almasry
2025-05-09 18:02 ` Matthew Wilcox
2025-05-12 12:51 ` Byungchul Park
2025-05-12 14:42 ` Matthew Wilcox [this message]
2025-05-13 1:42 ` Byungchul Park
2025-05-13 3:19 ` Matthew Wilcox
2025-05-13 10:24 ` Byungchul Park
2025-05-10 7:26 ` Ilias Apalodimas
2025-05-12 12:58 ` Byungchul Park
2025-05-09 14:09 ` [RFC 00/19] Split netmem from " Mina Almasry
2025-05-12 12:36 ` Byungchul Park
2025-05-12 12:59 ` Pavel Begunkov
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