From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 132BAC7113E for ; Wed, 11 Jun 2025 20:54:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 87F566B007B; Wed, 11 Jun 2025 16:54:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 830496B0088; Wed, 11 Jun 2025 16:54:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6F7D36B0089; Wed, 11 Jun 2025 16:54:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 51C396B007B for ; Wed, 11 Jun 2025 16:54:07 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id D47505B6AF for ; Wed, 11 Jun 2025 20:54:06 +0000 (UTC) X-FDA: 83544322092.02.7843049 Received: from mail-pl1-f170.google.com (mail-pl1-f170.google.com [209.85.214.170]) by imf30.hostedemail.com (Postfix) with ESMTP id EFB2B80005 for ; Wed, 11 Jun 2025 20:54:04 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=wuv1ta0v; spf=pass (imf30.hostedemail.com: domain of almasrymina@google.com designates 209.85.214.170 as permitted sender) smtp.mailfrom=almasrymina@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1749675245; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=+9ODZSh8S7aCPsxn2p/L7r5lbam9F8rTMEAJ1T+T72E=; b=4GguO062fSA4vTAllmRG9kziCYtcH2EeV7hwxkNBYm4+y9d77QRKnLPTPIWSB/Ggq7i0Hm JdU/eUUKIULM3tbRT57dJTauRFFoGzGqiT80Vsj5xjU9hCgCad7ThUZA7XNbXuo6PfYV9H nAedJ1jzIrS3QPDBk0uXjjwRPvUZz24= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1749675245; a=rsa-sha256; cv=none; b=37dfIGLjC7x7AdeQeUeivB/KY+QXJ0t6bSRD/VGiWNYtwgEXlquLXuI3+uIbuXiaTEWbWU PVJL3sYon1y82moigTc4oTErcn3JEH6kdc8zfPjBhaM5EeoPrwFZ5Ew3AeBguIM74KnJM4 +u/djuvnvMMcJXUrut13iE50vTN26BI= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=wuv1ta0v; spf=pass (imf30.hostedemail.com: domain of almasrymina@google.com designates 209.85.214.170 as permitted sender) smtp.mailfrom=almasrymina@google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-pl1-f170.google.com with SMTP id d9443c01a7336-235e389599fso58905ad.0 for ; Wed, 11 Jun 2025 13:54:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1749675244; x=1750280044; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=+9ODZSh8S7aCPsxn2p/L7r5lbam9F8rTMEAJ1T+T72E=; b=wuv1ta0v8n/UFGU9iPRgeE9/+w27BaCjmlkzEe6k8Ss8lNukhqMEBpEOEiWo7QlTpP O4HSh4bgHweiVfpq084o2YqGiYsTe76NlALgQAr53n6UkDjIY4Rw57DvJbx/yZkiFCWB QDEgsEmjpXnjvxPScs68QqxMCu361OMKbQDhKqFOQz9R0XPaso0c08GDi12BurrLdeht QCVETOZcdEBkxj9KJFt4OtY0AMBj6rpXwIsmrhqnkuRRGVQEMCLocxZVrnzRuiHM20Wg Mf/Oo/X1tiwSg+ap0rAP0Xt3MOBMFAkUPDoqNcv7RyTXeQ8A9JaGEBbRVgWW6yzaapKU E59Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749675244; x=1750280044; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+9ODZSh8S7aCPsxn2p/L7r5lbam9F8rTMEAJ1T+T72E=; b=sj4ZaZZLx1F4FqL3tzdxC8gfbZ2JgGPnmNR+BoDIQuL9LMwNorMO4I7LVsXXKF9VPi DrrIen4k8tNHUIkhMaCh5I8xM0R4SmivcP3RB0TPJpTrJX+TspJAvQ1olEfpoP56Q0XB OrVC4We4fd8UJO806Knc58NROcN5Fy/JYugGsa1cdAhbpys/AtJ6LxBXl8O6/oqr1r9z 0OxPCi+UvQ9uTfOOls8Yvp+4zZs6iNCE8LzJ6tWnn+dE981vxIhmxLGXvpL9HkStY6lA Dh/8rd22BPr0zbfHDbEewyhuQIcveCrJn8pC6mswqfmCieKPatxKfZOPvijS07FNPn2M NfXw== X-Forwarded-Encrypted: i=1; AJvYcCUgn4EsHC4+oVo6q4LQAfSfNeaV74JJSZKoCZTbVQ/AM4/ajTdSe54zat0Cf58K3UXSv7vbwwMxqg==@kvack.org X-Gm-Message-State: AOJu0Yxm/jjX3R0MqmKbcXc7t1bRFz5HUlN+wLyYP96ebVHV4ZfdOKKU P67VOtF2ZVM+SPz2UN37CkMuOcmRXDtjjGIrdfLJZ/Qx+uFz82J6mS6AXcnIQR3iaOzIS/QNzUp yZJOTj3YrmMTrCjaOP7Ghm/gRAvU0EJA2rtnc8oYd X-Gm-Gg: ASbGncuGEQo87j1cMtDhgLLiTRca/SKwP56s/ZRTXFM60J9oNgz0oyUmjI8WHqn6SW7 m+llgAr9n+o+fuIIFqjixQMm4vB7Etrrn5Ewi74+RgLTddKVEnshomyhCX/Byq2gx3N7R269BHI sPqv9x6XaKIjsLHI84tQHQ6wL2LPFCazeTm4QOsNvQBvlG1+lB11C0w95FHE3NfiHJxREZoQlJ X-Google-Smtp-Source: AGHT+IGNxlwvOT/63E8WfH8fOvLo/kbNgZNIZ0H/0cRMTD73xz3o38k6hHpr4p4XXDFuDJGxNZhFeuEoTw2UanOyEww= X-Received: by 2002:a17:903:4b03:b0:224:6c8:8d84 with SMTP id d9443c01a7336-2364dc4e0d5mr581215ad.4.1749675243498; Wed, 11 Jun 2025 13:54:03 -0700 (PDT) MIME-Version: 1.0 References: <20250609043225.77229-1-byungchul@sk.com> <20250609043225.77229-2-byungchul@sk.com> <20250609123255.18f14000@kernel.org> In-Reply-To: <20250609123255.18f14000@kernel.org> From: Mina Almasry Date: Wed, 11 Jun 2025 13:53:51 -0700 X-Gm-Features: AX0GCFs86j-gs5jhCZgm2IbPRLCZG610-Y9bqwTkXzjafc_yCgYbSIAlkglSp4o Message-ID: Subject: Re: [PATCH net-next 1/9] netmem: introduce struct netmem_desc mirroring struct page To: Jakub Kicinski , David Howells Cc: Byungchul Park , willy@infradead.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel_team@skhynix.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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Queue-Id: EFB2B80005 X-Stat-Signature: yjmskeuge3zxggc1ebpjdezcbqzmnkcn X-Rspamd-Server: rspam04 X-HE-Tag: 1749675244-341877 X-HE-Meta: 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 QGMN3P73 HtaW5iR2E1TLa2VRHzTWja7nPfk3XThmyM9PF63w7rXVZCKPqJFsm0pnELMgCb75hPCWOuJLkSE+HP5HWA5EVPKd+rCj3bQgyCne8pj36AVLLNX/qFsiMbnt/On2WW6MWFRaakgDulYOG58WMg31Qv8lq7DyLE48ezaGgvhDoL3OvP4Rl6+4HEcRp/r7Q0VMZrDEVorOXZH3XN0dnz6WlSc+MzqG+5ugtvVdnlVaVpD8ZsE4OZlhYbtJLcNreDuupWdEYA3lprtiH+mprulrrQ4+pOcMQbSW/O01OX5/brpCMH37mCqfcpcaKRGYdpDtFLE0wR3XsIEDIW+O3mvvEq/MFcTHUdCkLllxqfLRO1Vsv437rUwqovWiLzLZPrFfTJRmnKmIzugY4k7qDpdKKsGfFVzOa387uZQdN1YpQtnIGvHg= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jun 9, 2025 at 12:32=E2=80=AFPM Jakub Kicinski wr= ote: > > On Mon, 9 Jun 2025 13:32:17 +0900 Byungchul Park wrote: > > To simplify struct page, the page pool members of struct page should be > > moved to other, allowing these members to be removed from struct page. > > > > Introduce a network memory descriptor to store the members, struct > > netmem_desc, and make it union'ed with the existing fields in struct > > net_iov, allowing to organize the fields of struct net_iov. > > What's the intended relation between the types? > > 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 > relevant direction. Are you coordinating with David Howells? FWIW I did point David to this work in a tangentially related thread: https://lore.kernel.org/netdev/CAHS8izMMU8QZrvXRiDjqwsBg_34s+dhvSyrU7XGMBuP= F6eWyTA@mail.gmail.com/ I think yes it would be good to get a reviewed-by or acked-by from Matthew or David to show that this approach is in line with their plans? >From my end I tried to review to: 1. Make sure the changes are compatible with net_iov/netmem_ref. 2. Make sure what's implemented here is in line with the memdesc effort Matthew lists here[1]. In particular the netmem_desc struct introduced here is very similar to the zpdesc and ptdesc structs mentioned as an example in [1]. [1] https://kernelnewbies.org/MatthewWilcox/Memdescs/Path --=20 Thanks, Mina