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s=arc-20220608; d=hostedemail.com; t=1749519012; a=rsa-sha256; cv=none; b=QnAzHpec4CM1uORelNzKFv/PrUHxUt2GKBdKebFPFm9d6M6ROycD8z0yBy+zyeHJwDKT6L nPe961agIdS9YQXcdHmeXG20f0cuD+y8dQMlk7HQn7+3T0VMmMN9iBU6HM+0BauVjNvXQ3 /bFdIoXA9bG4NqTUUeLelQZ0Z0ggSBQ= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf25.hostedemail.com: domain of byungchul@sk.com designates 166.125.252.92 as permitted sender) smtp.mailfrom=byungchul@sk.com X-AuditID: a67dfc5b-681ff7000002311f-d5-68478a9e01f0 Date: Tue, 10 Jun 2025 10:30:01 +0900 From: Byungchul Park To: Jakub Kicinski Cc: willy@infradead.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel_team@skhynix.com, almasrymina@google.com, ilias.apalodimas@linaro.org, harry.yoo@oracle.com, hawk@kernel.org, akpm@linux-foundation.org, davem@davemloft.net, john.fastabend@gmail.com, andrew+netdev@lunn.ch, asml.silence@gmail.com, toke@redhat.com, tariqt@nvidia.com, edumazet@google.com, pabeni@redhat.com, saeedm@nvidia.com, leon@kernel.org, ast@kernel.org, daniel@iogearbox.net, david@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, horms@kernel.org, linux-rdma@vger.kernel.org, bpf@vger.kernel.org, vishal.moola@gmail.com Subject: Re: [PATCH net-next 1/9] netmem: introduce struct netmem_desc mirroring struct page Message-ID: <20250610013001.GA65598@system.software.com> References: <20250609043225.77229-1-byungchul@sk.com> <20250609043225.77229-2-byungchul@sk.com> <20250609123255.18f14000@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; 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One thing I'm trying to achieve is to remove pp fields from struct page, and make network code use struct netmem_desc { pp fields; } instead of sturc page for that purpose. The reason why I union'ed it with the existing pp fields in struct net_iov *temporarily* for now is, to fade out the existing pp fields from struct net_iov so as to make the final form like: strcut net_iov { struct netmem_desc desc; net_iov_specific_variable_1; net_iov_specific_variable_2; ... }; > netmem_ref exists to clearly indicate that memory may not be readable. > Majority of memory we expect to allocate from page pool must be > kernel-readable. What's the plan for reading the "single pointer" > memory within the kernel? > > I think you're approaching this problem from the easiest and least No, I've never looked for the easiest way. My bad if there are a better way to achieve it. What would you recommend? > relevant direction. Are you coordinating with David Howells? It's mm's project driven by Matthew Wilcox but as for page pool part, I'm working alone. https://kernelnewbies.org/MatthewWilcox/Memdescs/Path Byungchul