From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f171.google.com (mail-qk1-f171.google.com [209.85.222.171]) (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 1EB8E3AE702 for ; Fri, 6 Feb 2026 13:26:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770384378; cv=none; b=oVt6H/7n0fZYjw1fj1MIaEjiO7B3GyTzf8vPjo2PLNAWz0OrA2w41pLG6I1ZOF2XDJCIKuEVrPFtbVci0FyK4VaQ9XwDB5fkI3OcQrfYwcrE0v39OTxINgpDC1W4ufky2djjSEyzEBZPN8ug9BJm/DBsZV7WVJ+GNIJis7NyAcU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770384378; c=relaxed/simple; bh=QOyk0cfOiJKWpzq43+ntxyiecyFc7tSymZehLwBs/7U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TMPoC6iwDmeWYgYr1qee7poYl46Pvx0T+0WwttbvaDXo+MpmoYn+2mKMnOvM5DTruZY8QIdDwduLFOZnnhIHb3jeG/88kYVOlk/CVdVPaPyYfWQI49K8FCe1+q5ddXaL3+hymGN4ppEsQTM+J2xm9R5YgrTY2spbiA/qC7CGTEY= 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=N6cBfi+V; arc=none smtp.client-ip=209.85.222.171 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="N6cBfi+V" Received: by mail-qk1-f171.google.com with SMTP id af79cd13be357-8c533228383so120321885a.3 for ; Fri, 06 Feb 2026 05:26:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1770384377; x=1770989177; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=bcoHR9we9sqx3MppgWDXe17DIO+ggzqTTd2+g0R34PI=; b=N6cBfi+VELTLXd+MB42/nKMWKzxlWSVDmzJQAw0jmBEE9ZumFotHUi9zV3KdQZUhW5 IyrnFezD0cys67NGdgCt8M4wwf2fZc/zN1dEOjJ5ahgOnzS5SmctwpGukCyLIAkkvHVi IZBVtZV3YRHUMzDwEilnf2nTTMJ/pW6c1E7F3HWvQIRffePrrvo9Waqs5SFzB7+Sojzt 8YZEI7WW2dIDgzwojfh9MKCdYUTc4ITNAIXhOgUqHHzDgk1kaTRMWLhWgCfyIlVSu7Q1 BRFbGCcWag5aYKe+EP3vANe/yhjXg8pfnm9kBWpRhiGyLFGcHG3LJjBVMtcAKGnI7TQq CkzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770384377; x=1770989177; h=in-reply-to:content-disposition: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; bh=bcoHR9we9sqx3MppgWDXe17DIO+ggzqTTd2+g0R34PI=; b=i9qBmbuZ4K4HzGOX1yGGc9YWksSA+WqIkim9nx4s7DtCtquVB4bSrzpKUkdoLW2+vs i9Z28/JQxGHoYKgMhCGLofqrJ08Vw19VzBSmGHR4jRCO9TK72cpKe92NKJ3uq5/qqcfB yAR6eysx7IrFgMwG5/mV0GfWeOAzK7HqIOy6pYvoMOQiqV1sg2DY3ZUsQ/+BUiEV0mXJ QSTtZ4mn8BC92bOZZIIwNhbbNNCL61/X2UzVMZl+1yvRSY+o5kMiOM/m1hF+nUPGGu5V h6A+pThe4HO/Ql8KNt+2rrDkcyTOwQvtCd+Emt00g7Y/0g33tVPDIqW4oo/WQ7bTHSo7 dJoA== X-Forwarded-Encrypted: i=1; AJvYcCXzXNvszOopGhduz7MealRT31dzid5c9ctjddlwNUOz+80IGST08Qbz/sBZ39wFzI8/Cz+obH8+EBdDowo=@vger.kernel.org X-Gm-Message-State: AOJu0YxhZTaa7D1V1CYjXca8b5RGD3UxaFV8WUY9RdCPIdTLRafG9J/9 DLzY23QJKlldN9k2yBlEt4aXI8c/w4iPyn2IXg5UTycuV7FuBmUZoWjpGq9ZDwwGjXI= X-Gm-Gg: AZuq6aIU3ckjF0b6kG0JKdkEY3zvVoVw6p5/6qHOh9f8YMxi/kImUy/8o1EVp+JXeil XlmyX0SD93SqkyEG2lIB7+k4ug2ar6DglvvaQGoLGAoEKSVFl4U41dRcKoS/kfnzuUu94aJojBT nU5K5EIfGn9AuCagU7TqiIFW4DUzHFYhTk0z+e/tA2eCjaIdUbjRjqi5cUmWRxv3Daz9z2MKnBH 9T+Dp4SAJYCoPq4wfRPLnH5ssjGVgtcmLrawW5cEiDmzI4c2D4RxNLmDzamQFT0640RepM4fWV0 2v+mHfnZR2mM6ToAGAiNyJW+M6Gzs/eoehFND33SYe5XM/pdIrvTrPlDkryZWTkU6ZCevBYyKbK +sF3AaL5Z/bX3IBRZozrNrrIDsltKhGAR3SRU98sy2hgb26zAMxdKB7efrZevuJxj49XZmPfzpa n2kRsXixHB/9Mz6k/zfIH+PZoy0feOLUsp/8kaY+2o83FqKsMz7bcniZRp5qN9pgAu6XZIog== X-Received: by 2002:a05:620a:46a9:b0:8c6:b315:1452 with SMTP id af79cd13be357-8caeeb510c0mr350205685a.7.1770384376891; Fri, 06 Feb 2026 05:26:16 -0800 (PST) Received: from gourry-fedora-PF4VCD3F (pool-96-255-20-138.washdc.ftas.verizon.net. [96.255.20.138]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8caf81c118csm157292285a.24.2026.02.06.05.26.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Feb 2026 05:26:16 -0800 (PST) Date: Fri, 6 Feb 2026 08:26:14 -0500 From: Gregory Price To: Alireza Sanaee Cc: Jonathan Cameron , Ira Weiny , Dave Jiang , Fan Ni , Dan Williams , Davidlohr Bueso , Alison Schofield , Vishal Verma , linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org, Li Ming Subject: Re: [PATCH v9 00/19] DCD: Add support for Dynamic Capacity Devices (DCD) Message-ID: References: <20250413-dcd-type2-upstream-v9-0-1d4911a0b365@intel.com> <698270e76775_44a22100c4@iweiny-mobl.notmuch> <6983888e76bcc_58e211005e@iweiny-mobl.notmuch> <20260205174847.000065a4@huawei.com> <20260206110130.00005fc2.alireza.sanaee@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260206110130.00005fc2.alireza.sanaee@huawei.com> On Fri, Feb 06, 2026 at 11:01:30AM +0000, Alireza Sanaee wrote: > On Thu, 5 Feb 2026 17:48:47 +0000 > Jonathan Cameron wrote: > > I think both of these approaches are OK, but looking from developers > perspective, if someone wants a specific memory for their workload, they > should rather get a fd and play with it in whichever way they want. NUMA may > not give that much flexibility. As a developer it would prefer 2. Though you > may say oh dax then? not sure! DAX or numa-aware memfd If you want *specific* memory (a particular HPA/DPA range), tagged dax is probably appropriate. If you just want any old page from a particular chunk of HPA, then probably some kind of numa-aware memfd would be simplest (though this may require new interfaces, since memfd is not currently numa-aware). We might be able to make private node work specifically with membind policy on a VMA (not on a task). That would probably be sufficient. ~Gregory