From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f173.google.com (mail-qt1-f173.google.com [209.85.160.173]) (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 6C55E3B27E7 for ; Fri, 4 Sep 2026 03:18:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788491890; cv=none; b=HlwhJ0sbyZn9gmC3hWgkScRIGTimgTcRpRtUSuHx0QxC7tbEiakO+BX0Zzbns5jnC8kBO9WDOSsiVWylItw/O6lorlpfLOSAQkJrtpy+EgQ6UlDlyJKFNBgYwk1Fh2DwqgHLLsYOFV1DcQhoqFXpp3hVgj8tBjkBL/M0dIZvB4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788491890; 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=X1DZyW5+23YOCpZK7wIOsbkQVig62cuDLqmtGTrTQcGcs0uY5cSLcaVK43f+5AT9j62S+XLjkFkfS8cOtb/3xy4bOE08vzQ9wkttGevXMGxAZNYDuXRZ0fv0ResEETyy7CCqIpf2qIrEwb//CFDAviU0gqDx+k9JlzFm1gddmiU= 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=209.85.160.173 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-f173.google.com with SMTP id d75a77b69052e-5303932c4f3so3554511cf.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=FLkntdyTTivsMKuDgdnHcLOtja+mfvlzFNA++MEPBaFIT30mjUfoHaRfn07PTuuIpF 67AVKPLzZIqXsGZLazeuKtO2F59d7sDzTpIzCFLUCXDVgMKpTS21RoO5rMKcGnbV57WF dSG4r2TkF9aAUmF5Itp/lonJ4JYEEooGpNW3g1dztKmZU/FQ26Bbs7PvaS48relHpylr T7VcUIkzniqNtcIsl3tRb1t2pdZy7IH/ln3r3qEN1GNeVKFrbWj3tEsYbtUrUQTVDBbJ +lN1auIhuQiVyprheiW5p0f6WXtb9b8Lww3xn7uyRrU47UoF/s4de2AjC76SMQDqo1Br aZew== X-Forwarded-Encrypted: i=1; AKwUvBwnfu5LqhkP7G3MKhqHCmLFoib+86RvKTBeKYmuJP6cEO8Fp2k5/jjB2Eq3zUjHQuLrwOMUiuw=@lists.linux.dev X-Gm-Message-State: AFuF++mg1mS2P0YqqsTlkRG+2dFvTVxHP5cuIr67gkyqmVq92Ek6engp 8WwynMF5lqtHba9wpK0KPT/TyAq/tx2mGPlfh4IrcMFjhxRL55+ZlR7rMt2a/02euEM= X-Gm-Gg: AYBFou3DC1pUl9QUlvnEYhQT8HbWDPL8AS3duBx3oZvYLx3iWKev+iwv1cWZ6ZRj2Ni OcvGHPj+pyKL7nu5N+Jqanwn+05STqmZ8MCRdiaJVCM8Z+ft24d4dzqipSxNBfbCha2neiD824/ 8x35lvveUM1t9xwV3K88W/lJRX1GB/BzJVmfs+0fvLvW043Zl7PujM8YeJ4aDEUOcv8iuF8zMSX 8h6Qj2937tl5w2/UM7eNlFhnG+aO/WTEiV6kiYNUtVglMo01FVCrIONue9fhXI4jLFu+4Kycb+m y1WxNBXMPatUyQCt172zPcIbKdhz84K2IzJyukqKjmoSQM+QGzwrLHDgRK2vol0IsVit5R02C2+ ldYv5CwIXMYymLKr3HJb9a4CRBnXgLFJEdlD79ouEeBGUWxAIGVF8j1HGR4RSeQCc/jM6ThzoPZ T0/VTxCq4DjPnVs/CzWk8XoSZfdH59OndUPo8WY9iS1dDXYHVy21A3DuutGrm9ACAO2tP+4dN6G 9ezoJIVQr8/aXaQzlgpVhzutGYNOBwwdZgUsaWdd4C5UesKA6TfKEI= 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: nvdimm@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