From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f172.google.com (mail-qt1-f172.google.com [209.85.160.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75CA53AFCED for ; Fri, 4 Sep 2026 03:18:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788491891; cv=none; b=IjF8bV0B5MclR5YY9BlfzdC2HzzEL4N0loJyrIELXsDcSxJvY3r2xEddEOyqmvrwzm1Oram1C+KMR3iG3B+RsNFQB3RzLhdqbKeCw/U/NcAdSx008rlL1/cHHXflWKiSmMmyPg1IG7GEIeAL7vhDCplG31kviu3lGH+ebnoBkJI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788491891; c=relaxed/simple; bh=AIU6NGTW/RpZfTt6y2cuypcAmkoFDaCDqNNZTCJi0Bc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NxSNw9dx7k+NrW5r/p8EYarm+82yUx2hEhZMX/ZMBuFICVnY/FCIb50XO6qg3uOtWAx0Z3/xhiP5bR21hv+Y52PiSGgzSI5+JSB24SQjkfTHrVJtAOZoK3oIlpde4nRDBqqAgVHhcFWYAFUMFuUDEL1eQYnEGseFpKrBwD2KYMU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=TMvCPDQy; arc=none smtp.client-ip=209.85.160.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="TMvCPDQy" Received: by mail-qt1-f172.google.com with SMTP id d75a77b69052e-5303932c4f3so3554551cf.2 for ; Thu, 03 Sep 2026 20:18:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1788491887; x=1789096687; darn=lists.linux.dev; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=I82bST350eZ9tF0sXAbqbqSO4hf+URoRFBA/uGedV7I=; b=TMvCPDQyOb/vTI12GLkN4vp7j6+ugwdbUzLy+CNCkZCnlED1/KJx8ZcvlrZaOWhudQ f1nONftzN6Izwu/bGGkxNf9wLko47wzSo0ys/0cDPTNj8Pv8gPIStbk0abka1vj2KeAF VJEhfqUOdiftbCra6JISz3WWsCq/OrQ2xdIfkvbPhxnBc8v5C7Yj4EWRF+jOKYUQWhd1 9ZAJ4EWitEes/aeLELL8Yl5h5n5b1tnr/qDJuOlMDZcUDaDjm3eMp6Ve2T0/gMR512ID BH+vK9QSFcw1FE2lXhWvvuoU5OYfnCtNylatS0kqWsQxfFBuEQyz8phvLkg7tcpiRRV6 AC9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788491887; x=1789096687; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=I82bST350eZ9tF0sXAbqbqSO4hf+URoRFBA/uGedV7I=; b=SrXYZ8UGHy4iz4lq+I7tY72do8KbyKCKS727gKyxLb7w4Vdg563IQmet5Q7+pc+w3Q 77jYuKIhdybYEj+6YFBi/9M4ClRMwGOgddOR/8+NMTJuzh4+8QfQJB9Y1gxBVWnhukOa 1rM35E57Ha2xVXY2uRO6c7zR78qj07F9lj0p7v3xFEkAY/d7Yqc245CrkvAIwyuxXqxM KR01GjmDpf+GlQfFeyHtzF65ICUyR3/BOwti9LhchJGUSuOxOlsmqJ5fOyO8jXZ7fYY6 4V+V2eLL8nZe3VQOpMc+uBrM2tRgybLIABLIBX24yuvmpmwSJEekoCuJv1e4MAJn8ZZ1 ZfDA== X-Forwarded-Encrypted: i=1; AKwUvBxI5AwWw0X/s72pCa2DllUAgxLp+IuqqMuoJiXrdu1piwUk5x/rc+KpUR7VCxvQ3+4TAHrjrnM+ftElWQ==@lists.linux.dev X-Gm-Message-State: AFuF++k/A9MIyqzJIrnbNjJckS0mfpCY8yuiVRbP7hMRV2ktXJUCFCQS +Qi8N1rA+VnMgNyAUwo5yRXe4qGZKD+L49MoXaT7o2Ponvc4CuLoxCUnS9ZUjWVuIdo= X-Gm-Gg: AYBFou0MEKxOe0XMuvC2yk0X+d3RApZjoNjfIbWFYRDLaAwNhMtyV9XqHc9hBuHRgqR E5OnCtRBaSXVFqLkPdhCB/2Nt1jiFgQnPkeLK7fw4pssCMUCSos3Hs9StIhB5v9srcGOdrrjMGo 3rLatR+4FV7BI/Q25OGM9QIzwzkUz6wZfiEIQkaxW8S6DSW4EzCYyOy12S6gC49wZAPaNCfNKyP jGsQN7M9sZrSNfi3sP0nyTC3vlb5vlXZ5pv4YKL6l70lFesL2mfRDKS5KYHp7FZg1mT3M5Uw4Eo +8CkhOTxkyKfohw7GncQnZIgbBRaijLorM3LiryFxhf+9IDwNz1J70eU9xD1teavmEmFrUJBHU1 QicFT287iSx3DjY+w5odALZ1AX16ZQXNm3IjAzTGL9djXJQiH0Rsvy30ksTMbID3l36bk9YX6Kb xIvDsmwuqA0r6h1XAapub8ytA6mboXL0IDTRlersy5C0i1C14BsH9FKLiZe3d9WMaFlkd02aPi6 5Ag3SKEWyFOGYCWPVZ+a0A0BxrH6TVu9UKwU9xiUUvsas/NWHOsn+g= X-Received: by 2002:a05:622a:1c18:b0:52d:4f43:d5b0 with SMTP id d75a77b69052e-530548bc5e0mr43078621cf.22.1788491887027; Thu, 03 Sep 2026 20:18:07 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F (pool-173-79-60-52.washdc.fios.verizon.net. [173.79.60.52]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5305402a7b7sm11260161cf.3.2026.09.03.20.18.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Sep 2026 20:18:06 -0700 (PDT) Date: Thu, 3 Sep 2026 23:18:03 -0400 From: Gregory Price To: Qiqi Li Cc: linux-mm@kvack.org, Zhigang.Luo@amd.com, arun.george@samsung.com, balbirs@nvidia.com, brendan.jackman@linux.dev, yuzenghui@huawei.com, apopple@nvidia.com, alucerop@amd.com, matthew.brost@intel.com, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, corbet@lwn.net, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, djbw@kernel.org, vishal.l.verma@intel.com, dave.jiang@intel.com, alison.schofield@intel.com, osandov@osandov.com, jannh@google.com, pfalcato@suse.de, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, pbonzini@redhat.com, osalvador@suse.de, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, ying.huang@linux.alibaba.com, kasong@tencent.com, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, yury.norov@gmail.com, linux@rasmusvillemoes.dk, longman@redhat.com, ridong.chen@linux.dev, tj@kernel.org, mkoutny@suse.com, sj@kernel.org, jgg@ziepe.ca, jhubbard@nvidia.com, peterx@redhat.com, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, lance.yang@linux.dev, usama.arif@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, roman.gushchin@linux.dev, muchun.song@linux.dev, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, driver-core@lists.linux.dev, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-debuggers@vger.kernel.org, linux-fsdevel@vger.kernel.org, kvm@vger.kernel.org, cgroups@vger.kernel.org, damon@lists.linux.dev, linux-kselftest@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v5 25/36] mm/memory_hotplug: support N_MEMORY_PRIVATE node hotplug Message-ID: References: <20260720193431.3841992-1-gourry@gourry.net> <20260720193431.3841992-26-gourry@gourry.net> <6840c720-8cb7-46bb-a652-040c130a4427@huawei.com> <0334fe7d-d949-45f7-8914-3012cb11b740@huawei.com> Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0334fe7d-d949-45f7-8914-3012cb11b740@huawei.com> On Fri, Sep 04, 2026 at 09:05:39AM +0800, Qiqi Li wrote: > On 8/17/2026 8:49 AM, Gregory Price wrote: > > It would need to be reserved, and you could use numa emulation but > > that's clunky. I have an RFC for exactly this issue - though i haven't > > pushed it further yet. > > > > https://lore.kernel.org/all/20260610014517.253609-1-gourry@gourry.net/ > > Hi Gregory, > > Sorry for the late reply. > > I took a look at the exclusive-node RFC. The approach looks useful for > device-backed private memory without a firmware-described NUMA node. > Thanks for the pointer. > > We are currently looking into the private-node and CRAM design as a > whole. I noticed that CRAM was not included with the v5 series, and saw > that others were also interested in a v5 version. > > If you already have a CRAM branch or patches based on v5, even if they > are still work in progress, would you mind sharing them? It would be > very helpful for us to continue testing the overall design. > I dropped it off because it was starting to become unwieldly, but i am continuing to maintain a branch on my github: https://github.com/gourryinverse/linux/commits/scratch/gourry/cramtest/cram_72/ I have not posted a new version in some time and it has been reworked significantly in the past few months - but I plan to talk about this particular branch and the tests I've run with it at the device memory LPC micro-conference. I validated this branch against most in-tree (relevant) filesystems for the page-cache extension, but I imagine the anon-only version subset is the more immediately interesting for upstream development. I may include the anon-only version in v6, but I've been a bit busy shoring up the base private memory node core and implementing kernel selftests and LTP tests to ensure there's no userland api regressions. I hope to get something out later this month. ~Gregory