From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from invmail4.hynix.com (exvmail4.skhynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 68B572D0C7A; Wed, 29 Oct 2025 01:56:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.125.252.92 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761702983; cv=none; b=gB6BdnOVcDL0D1rYvYxjHADIDpA6jvgR8UDD4xjQ2Kv9gANCLij0nxJB9SVwtoooeuOdz6LS2m89sOHaP4QiIKpXEygKBGrVqnkPheYkpWmeNJ9XH/ltAxQ4OP4A2VKxsZRq9C3MFDiw38KXL3Nh67SxYv9/+m1dt5+eVnKMnzI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761702983; c=relaxed/simple; bh=oNEBHuq2LmK+th/kjOkTgOWVlI8Rc6Yn1bP3zYucX84=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZUgrdtD2rLDnF5HKNmFK7kIx0uZmPAO2d+9LVGvSi9rSLnVeOyy9gaI+PTMC8fyoWE6NP7hx+rPoO/Qn5kdrFJURLuHwb/Ow9hq6yuXPrKU04LG8tB1kxQgM/Z5eIx/bcfWE2HUfQ1T6oBMCd/9wWKWHxhPmuNpqj1ne8lIEhuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com; spf=pass smtp.mailfrom=sk.com; arc=none smtp.client-ip=166.125.252.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sk.com X-AuditID: a67dfc5b-c45ff70000001609-f7-6901743d1673 Date: Wed, 29 Oct 2025 10:56:08 +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 v4 1/2] page_pool: check if nmdesc->pp is !NULL to confirm its usage as pp for net_iov Message-ID: <20251029015608.GA37879@system.software.com> References: <20251023074410.78650-1-byungchul@sk.com> <20251023074410.78650-2-byungchul@sk.com> <20251028183356.29601348@kernel.org> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251028183356.29601348@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-Brightmail-Tracker: H4sIAAAAAAAAA02SbUxTZxTH99zn9t5LY81dBXmmm3GdZoYEBILmbEHDzBKfDyok+mXMZDb2 blTbYlpeTVyqYhQjlSEqLSwDjbzWsJWNvgTMVqCAmM1UwetgoPhCVECCiPIi2GrM/PbLOf/z O+fDEbC6R7FC0JuyJLNJa9BwSlY5tqQqdlMW0sc/7l4HFY1ODhpe5kHNHY8CZpwjDFTUNyOY munnYbE1gOBZeycHT9omEVysmsZQ8U8BC88bZzF4fSMIHpdd5uBBYJiHBtd2GKp+yELLcTeG 4dNdHBQVzGFonRnn4YinNiRusvJwvdmmgNLZSxjc1js83PBVcDDoXFTAQ38RC92OOhYmzrZj GLKlQKByOUz3jCJob3QzMH3qZw567T4G/mjt5eFMsJKDewVDCIJtwyycnT/BQflhG4K5lyHl ePGUAso7BvmUOHpYljnaNvoU09/rbjO0r+wnlspXrjLU6/iPp5WubNpUG0NPykFMXfWFHHVN lvB0oK+Fo11lcyz13v2Cej3PGFp0dJxLi0pXJuskgz5HMq/fvEeZ8cpn4w4EFXkNVX8jK3Kz J1GEQMQkci101Ds+d+T8G2bFtcR3vFQRZk78nMjyDA5zpLiGFDTZQxmlgMUJnpTJg6GQICwT jaSj1xjOqEQgiy/qcTijFk8g0ubtZd42PiTd9vtvFmAxhsgLj5jwLBZXkpoFIVyOEBOIvfoC F+Yo8TPyZ3MnE/YQcUogo4XX8NtDPyJ/1cpsMRId72kd72kd/2srEa5Har0px6jVG5LiMvJN +ry4vZlGFwq9WPWh+W89aPL6Tj8SBaRZooq/8IFerdDmWPKNfkQErIlUjZ4OlVQ6bf5ByZz5 nTnbIFn8aKXAaqJVidO5OrX4gzZL2i9JByTzuy4jRKywovMls/ZF54ODxbryru9tm+qid3nu 5+7QrS10zKcNDJiTTQmfXKI/Pi3eMpt3c9mtY6WuuaHUX9PZWNfwwpUNO7Y4X/TYU5N2GwKJ W0sDzC8l+RtTsrdZ+hOqc79aerfT/Y1nbNXXp2K/3DdiDc4n7mlUGVb3J+8aW9OS+vHF35pv fur/V8NaMrQJMdhs0b4Gq9SA+l4DAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA02SXUhTcRjG+5//Of9zthyczOxUdtEqpEEfRtHbJ14EHYoiuonqQtc65HBb taloFCwbZZbTPiy3ZkwlLbWEWepGVmxmWdGHpp2o1OzDPsSkzHLmbCui7h6e5/c8783L4ehL zFROb0qTzCatQU2UtHLD8oNzV6Yh/QJvLg+ummoCVT8yoaK7gYHh6l4KXJV1CAaHn7Mw1tiM 4GvTbQKfAl8QlJUMYXA9tNHwrSaIwevrRfCx6BKBt809LFR51kNX+Tsarh2ux9CTf4dAnm0E Q+NwPwvZDRfCw7VWFgLFLQw8qrMzcCp4HkO9tZuFNp+LQGf1GAPv/Hk0tDgv0jBQ2IShy54I ze5YGLrXh6Cppp6CoWPFBNodPgquNrazcLLVTeC1rQtBa6CHhsKfOQTOHrAjGPkRnuwvGGTg 7K1ONnG+eECWiRjo+4zFKxefUWJH0XFalK/fpUSv8yUruj3pYu0FjZgrt2LRU3mEiJ4vJ1jx Rcc1It4pGqFF76ulorfhKyXmHewnG2O3KlfskAz6DMk8f1WyMmXUZye7W5nMqpIHyIrq6Vyk 4AR+kXA6+8xvTfOzBd/hU0xEEz5ekOVhHNEx/CzBVusIM0oO8wOsUCR3hiGOm8gbhVvtxgij 4kEY+16JI0w0n4OEgLed+hNMEFocb34fwLxGkEMfqEgX89OEihAXsRV8guAoLyURPYmfKdys u00VIJXzv7bzv7bzX9uNcCWK0ZsyjFq9YfE8S2pKlkmfOU+3y+hB4Scq3//zeAMabFvjRzyH 1FGqBaXj9NGMNsOSZfQjgcPqGFVffthS7dBm7ZXMu5LM6QbJ4kfTOFo9WbV2s5Qcze/Upkmp krRbMv9NKU4x1Yq6O3XeMWaKYU1B/uWOwkMz6kYSEzRRtn56TvrCh0/8CteS6Sv7NOMLXsXH jeriP0PbfeK4Ejq6ddU5zdOBM8GPul5tRtU63Z4cHbW5efEbU1KNNVNxQ97HrzOPixNWV9i3 LMl/v6yMCXY8z45NjQps2p6b/DipJy748sXT16Fto2rakqJN0GCzRfsLmdJKBkADAAA= X-CFilter-Loop: Reflected On Tue, Oct 28, 2025 at 06:33:56PM -0700, Jakub Kicinski wrote: > On Thu, 23 Oct 2025 16:44:09 +0900 Byungchul Park wrote: > > As a preparation, the check for net_iov, that is not page-backed, should > > avoid using ->pp_magic since net_iov doens't have to do with page type. > > doesn't > > > Instead, nmdesc->pp can be used if a net_iov or its nmdesc belongs to a > > page pool, by making sure nmdesc->pp is NULL otherwise. > > Please explain in the commit message why the new branch in > netmem_is_pp() is necessary. We used to identify the pages based > on PP_SIGNATURE, now we identify them based on page_type. Yes, I will. It'd be much better. Thank you very much for the comment. Byungchul