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t=1762736977; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bDYU+gQtoSksq3wtRmN5VuMeoTHNRFitVorG0gaqH1o=; b=EkRgyGC3jACrQjnExD9K2hC498YtQVPpsjxJjWPxrYNjwJGkdMor9beL2pH5AZaMJ8wy7o eUxV43RdYTLawHTx0AyJusYwKV1kTXfCCileCrjJIoORBU7SCFSOfHW4PJGVWm8OvqJ10F gNtylTGqLw27LddQ39gXcxYNF6EB/rY= X-AuditID: a67dfc5b-c2dff70000001609-52-69113b4c406e Date: Mon, 10 Nov 2025 10:09:26 +0900 From: Byungchul Park To: Jakub Kicinski Cc: linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel_team@skhynix.com, harry.yoo@oracle.com, ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, saeedm@nvidia.com, leon@kernel.org, tariqt@nvidia.com, mbloch@nvidia.com, andrew+netdev@lunn.ch, edumazet@google.com, pabeni@redhat.com, akpm@linux-foundation.org, 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, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, ilias.apalodimas@linaro.org, willy@infradead.org, brauner@kernel.org, kas@kernel.org, yuzhao@google.com, usamaarif642@gmail.com, baolin.wang@linux.alibaba.com, almasrymina@google.com, toke@redhat.com, asml.silence@gmail.com, bpf@vger.kernel.org, linux-rdma@vger.kernel.org, sfr@canb.auug.org.au, dw@davidwei.uk, ap420073@gmail.com, dtatulea@nvidia.com Subject: Re: [RFC mm v5 1/2] page_pool: check nmdesc->pp to see its usage as page pool for net_iov not page-backed Message-ID: <20251110010926.GA70011@system.software.com> References: <20251103075108.26437-1-byungchul@sk.com> <20251103075108.26437-2-byungchul@sk.com> <20251106173320.2f8e683a@kernel.org> <20251107015902.GA3021@system.software.com> <20251106180810.6b06f71a@kernel.org> <20251107044708.GA54407@system.software.com> <20251107174129.62a3f39c@kernel.org> <20251108022458.GA65163@system.software.com> <20251107183712.36228f2a@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; 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Can we not move owner > > > to _pp_mapping_pad ? Or reorder it with type, enum net_iov_type > > > only has 2 values we can smoosh it with page_type easily. > > > > I'm still confused. I think you probably understand what this work is > > for. (I've explained several times with related links.) Or am I > > missing something from your questions? > > > > I've answered your question directly since you asked, but the point is > > that, struct net_iov will no longer overlay on struct page. > > > > Instead, struct netmem_desc will be responsible for keeping the pp > > fields while struct page will lay down the resonsibility, once the pp > > fields will be removed from struct page like: > > I understand the end goal. I don't understand why patch 1 is a step > in that direction, and you seem incapable of explaining it. So please > either follow my suggestion on how to proceed with patch 2 without struct page and struct netmem_desc should keep difference information. Even though they are sharing some fields at the moment, it should eventually be decoupled, which I'm working on now. > patch 1 in current form. Or come back when have the full conversion > ready. This patch set represents the final phase of the full conversion process, awaiting the next steps. Once this patch is completed, the entire conversion will be finished, allowing for the final patch that removes the pp fields from the struct page to be carried out. Byungchul