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 2BA4329373F; Mon, 12 May 2025 12:36:32 +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=1747053399; cv=none; b=XCf4ijiOXwa3ECQIyqJmS6s4BIVZb1grngGwgrWFeZej8li0rTI5MiG+tF6GcxaNZt+TbQqVAokS7GHttc7cIBqj2AJ7jcfauZ9cYuCAZyAVIWbgOxoqb1hZU4FL3wcXRRz4Tkdkm6fXgLA/kfT3QufWUBlEBwauRnuPRcSfS9w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747053399; c=relaxed/simple; bh=g4nck2QMZGwAZ9w81HswNK6wCtGG7pe79Jg7VJ70KhQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GBrX53pMjMXhfAxTeOIWmL2ygRMg0rW8QFAe4my5tiWMh93rlCaBUF2Ij3my3QaXl8dLoVjFxkl041btZKxuBVRGLgviN/SgOTd6NSTRUvJpH/0xtT8OaUMnsm8dROdF5oo9m2kQfoYrfbQfgnc162MMVKaNsJsp6DZ2i0F7Zlw= 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-681ff7000002311f-07-6821eb4fc11d Date: Mon, 12 May 2025 21:36:26 +0900 From: Byungchul Park To: Mina Almasry Cc: Pavel Begunkov , willy@infradead.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel_team@skhynix.com, kuba@kernel.org, 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 00/19] Split netmem from struct page Message-ID: <20250512123626.GB45370@system.software.com> References: <20250509115126.63190-1-byungchul@sk.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrLIsWRmVeSWpSXmKPExsXC9ZZnoa7/a8UMg9OX5CzmrF/DZrH6R4XF 8gc7WC3mrNrGaPHl5212i8ULvzFbzDnfwmLx9Ngjdov7y56xWOxp385s0dvym9miaccKJosL 2/pYLS7vmsNmcW/Nf1aLYwvELL6dfsNosX7fDVaL3z/msDkIe2xZeZPJY+esu+weCzaVemxe oeXRdeMSs8emVZ1sHps+TWL3uHNtD5vHiRm/WTx27vjM5PHx6S0Wj/f7rrJ5fN4kF8AbxWWT kpqTWZZapG+XwJWx5ft99oKjvBUPv69nb2A8zdXFyMkhIWAi8eDlVXYYe+HP00wgNouAqsS+ TwvBbDYBdYkbN34yg9giApoSS/ZNZO1i5OJgFjjLLPH10zlWkISwgJnE8cs3GEFsXgELiWnT 24GGcnAICdRIbDmTDxEWlDg58wkLiM0MNPPPvEvMICXMAtISy/9xQITlJZq3zgZbxSkQKDGp +z7YCaICyhIHth1ngjjzHLvE5z/pELakxMEVN1gmMArOQrJhFpINsxA2zEKyYQEjyypGocy8 stzEzBwTvYzKvMwKveT83E2MwEheVvsnegfjpwvBhxgFOBiVeHhPvFTMEGJNLCuuzD3EKMHB rCTC27gdKMSbklhZlVqUH19UmpNafIhRmoNFSZzX6Ft5ipBAemJJanZqakFqEUyWiYNTqoFR x+LqkVKDxgeRRnLyHG7qPb4Sew6Vx1mJnszo3P6x4/HXprNJSz7e4z+2k/+70bO2masVG7vM 3045LHf2srUnV7zzPrNGrWlqiQf3v55zv2vjR9789uz4ubkaQf93lZ9oKWoytVTrDZN6+Hri 93CTkxcXOmqtDM7wqX/W5vctLHfVAZNT6ycpsRRnJBpqMRcVJwIA//ACmuACAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrKIsWRmVeSWpSXmKPExsXC5WfdrOv/WjHD4HWrsMWc9WvYLFb/qLBY /mAHq8WcVdsYLb78vM1usXjhN2aLOedbWCyeHnvEbnF/2TMWiz3t25ktelt+M1s07VjBZHF4 7klWiwvb+lgtLu+aw2Zxb81/VotjC8Qsvp1+w2ixft8NVovfP+awOYh4bFl5k8lj56y77B4L NpV6bF6h5dF14xKzx6ZVnWwemz5NYve4c20Pm8eJGb9ZPHbu+Mzk8fHpLRaP9/uusnksfvGB yePzJrkAvigum5TUnMyy1CJ9uwSujC3f77MXHOWtePh9PXsD42muLkZODgkBE4mFP08zgdgs AqoS+z4tBLPZBNQlbtz4yQxiiwhoSizZN5G1i5GLg1ngLLPE10/nWEESwgJmEscv32AEsXkF LCSmTW9n72Lk4BASqJHYciYfIiwocXLmExYQmxlo5p95l5hBSpgFpCWW/+OACMtLNG+dDbaK UyBQYlL3fbATRAWUJQ5sO840gZFvFpJJs5BMmoUwaRaSSQsYWVYximTmleUmZuaY6hVnZ1Tm ZVboJefnbmIERuay2j8TdzB+uex+iFGAg1GJh/fES8UMIdbEsuLK3EOMEhzMSiK8jduBQrwp iZVVqUX58UWlOanFhxilOViUxHm9wlMThATSE0tSs1NTC1KLYLJMHJxSDYz+tVElnb3lWzL2 vjZXrIn0LrTYvXtCu6/4EsP+ZbLG/xbtYCvtkSosYf57zdlPzOB1Lq9n15qvV6ccOXLwmIhY dLcs64qCc1+MPHTKp3ZIflrwv3JDvGrXb+4Vph8d1H4fO/av+sfkQ+tO37t8N6Jj/fs3U//V RF5m0/5ml/fm/fTtpjurT51XYinOSDTUYi4qTgQAYc+tCMgCAAA= X-CFilter-Loop: Reflected On Fri, May 09, 2025 at 07:09:16AM -0700, Mina Almasry wrote: > On Fri, May 9, 2025 at 4:51 AM Byungchul Park wrote: > > > > The MM subsystem is trying to reduce struct page to a single pointer. > > The first step towards that is splitting struct page by its individual > > users, as has already been done with folio and slab. This patchset does > > that for netmem which is used for page pools. > > > > Matthew Wilcox tried and stopped the same work, you can see in: > > > > https://lore.kernel.org/linux-mm/20230111042214.907030-1-willy@infradead.org/ > > > > Mina Almasry already has done a lot fo prerequisite works by luck, he > > said :). I stacked my patches on the top of his work e.i. netmem. > > > > I focused on removing the page pool members in struct page this time, > > not moving the allocation code of page pool from net to mm. It can be > > done later if needed. > > > > There are still a lot of works to do, to remove the dependency on struct > > page in the network subsystem. I will continue to work on this after > > this base patchset is merged. > > > > This patchset is based on mm tree's mm-unstable branch. > > > > This series largely looks good to me, but a couple of things: > > - For deep changes like this to the page_pool, I think we need a > before/after run to Jesper's currently out-of-tree benchmark to see > any regressions: > https://lore.kernel.org/netdev/20250309084118.3080950-1-almasrymina@google.com/ Sure. I will check it. > - Also please CC Pavel on iterations related to netmem/net_iov, they > are reusing that in io_uring code for iouring rx rc as well. I will. Thank you. Byungchul > -- > Thanks, > Mina