From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) (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 54B8B396D2A for ; Wed, 25 Feb 2026 14:43:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772030614; cv=none; b=r7fY3LmdGEF1pMnq2achMIHgfuv0jNxDd3jAkHj5WDQOu5/JIc3hfCPfIjJPJjYp29OIXZmvBiQORo4FA2CMN2oAaCRFlg7r/o8ADa3sA1IppXRAol5BCDwGQg1BRoOMabCZ+Vm4Pb+jnlsQ5dFGSwpg1fQfD9NpJqazb6i9shk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772030614; c=relaxed/simple; bh=JHk303on0tH87FgVMmdu//2A2EJ68pOsAbk2jtfSs8E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jJkKL6ZxTpeGmpXUieFBAC81YHJtBZp5Rg5TqmD1lR7QAqQ2znXsMqoBB7DZOxOItZwra0r2MSGe0jV+WJptIVI6S2gfjxue5MK8x2Z09PfyMM/6mPusN2Yx/BwsQFt0Sfsad6fvu+lLQgBEksfkzeQufjHeIUtbf3WJuqoQPIk= 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=t1djVl/i; arc=none smtp.client-ip=209.85.160.175 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="t1djVl/i" Received: by mail-qt1-f175.google.com with SMTP id d75a77b69052e-506a3400f30so8545061cf.1 for ; Wed, 25 Feb 2026 06:43:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1772030612; x=1772635412; 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=foY2Y5omQw20sTq6/J6XKrTrTufvDv+fOLstkti1G50=; b=t1djVl/iPQRVN8ydau/gloFLvPYLeBj3NAQsvuTSxKRsGcVR7pvgfrO2YsMihEAT48 ey0ZOV9tfblTcVfcxp0ZYCZwczuWC6f1ARjG2e5AyNw6PZWaXTVN7Q78yd3iMQ9od4kv DgIyK/i454jAIPPyAJCu3CT6Q05qxMz076L2GDn8nMeTXUfheiAsDDgqbtT3OkUlgiRR LC/5UMLHmWCmJUHaCeepzNeRD0OD0JgA3BjeVCWDIBOBRShvs/agJyY1xZNeBrye+jih 9lyJI6eJ0VW50faAzl5aepCMhFHMXWFW3uXie3yvGX9sO2d7CXrnE2lgfrwRa1XcaVP/ HtLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772030612; x=1772635412; 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=foY2Y5omQw20sTq6/J6XKrTrTufvDv+fOLstkti1G50=; b=aoejzap9E706aVU2cs6P2YcfyEQJzlr8dfE1A8IOwt+GFWSrhTumsN3rvayv6nJCnK wbmEQNIGDFgYAh7OudZtDest9p2hG7dsM1HlYqV9cpGrm+6p2u2fPH4Xm/Db05ktIzBi cMbRR5DzkSkGB1Jb+AKlFdOGGoezmB6ktYtdcG0gxBxc9FgPNZtsxzx7XUmVl0Bo8lBx Z4qTDZLGJFMnn1l9h0AP9FbtS0HN8/6LDQCtqtdgEwcvjPW3tZdCIFVoMJ/EMnDBU0Bo lB/2487XErCWbDfit/B6tDCSYvLyKtTyZNNEIRGULvka1B5sA9wC72u47jfWtsFN9zqa 7dPw== X-Forwarded-Encrypted: i=1; AJvYcCVJ47x56LGJqTb0xPXdiONo75OcHY4El/HtF/t7pyIz1VnYiLr5gr85STgQhlhXzclRnTbGM9Q/K+9iLrVb25K0pks=@vger.kernel.org X-Gm-Message-State: AOJu0YxUzzjaVDyLqc/AFJHwndzo6c/tQrtucGuv73n87Mom+0iDvTnG HWh3Wh+/AcfndwsekCMVOjx/vUZ5KqjEKxtgweyAkAeiK74PQiohuQ08NMV3ZQox0M4= X-Gm-Gg: ATEYQzyHJ9za3Ef2PidzdrI4ALfHo36HdgqGs2pDwQ9jhkKiqwv6RsjrIkkcEnBA1MI VSVZsiS25b8XHjEz2wgsJT/o1dHe3paZPBuRk2cOLvzI7e5OlVEhYMakGUZZwFOh4KRK3DOBCYF FqZdsQyNQe1pENwKbEhtA2o50ydISREOuFA2AZDpefda0eAv0Ajpesxz6WKQ0QpWA5Jw3GK16yQ c4bPq3klc3UlcTB3v5YxKrXCMwJ1uOr/b4zlM0v3IWBcHbApXhGDq8vVPo/tYFsojMl8NNp4BKa 1nJ56MZ7aqlLWww4HIz/WouKJxfFdx0wXBQbbUZlBVCn+zKK2CO6kON2XsMGJw7I3Kuz6h73xMI FK4/3eGROawWKaUc/TVP5tnbzQGtFlGZZiNawqBZoN6H7W3nuPcTneOKSxTErmqX2yddsy4pYY7 pRxxpO5ZZIBQsQnEmJD8iRICfkIUOmU6OeJ0OJq01cFDgBIDQNpfQs7GXwADx6tGVqt8HkYRqOp ajaQwMuFEy4KP/4m5QJ X-Received: by 2002:a05:622a:1453:b0:4f1:e79a:1e0 with SMTP id d75a77b69052e-5073659bc05mr41895291cf.20.1772030611934; Wed, 25 Feb 2026 06:43:31 -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 d75a77b69052e-5070d510a7asm123124661cf.1.2026.02.25.06.43.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Feb 2026 06:43:31 -0800 (PST) Date: Wed, 25 Feb 2026 09:43:27 -0500 From: Gregory Price To: Alejandro Lucero Palau Cc: lsf-pc@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, damon@lists.linux.dev, kernel-team@meta.com, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, dave@stgolabs.net, jonathan.cameron@huawei.com, dave.jiang@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, dan.j.williams@intel.com, longman@redhat.com, akpm@linux-foundation.org, david@kernel.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, osalvador@suse.de, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, ying.huang@linux.alibaba.com, apopple@nvidia.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, yury.norov@gmail.com, linux@rasmusvillemoes.dk, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, tj@kernel.org, hannes@cmpxchg.org, mkoutny@suse.com, jackmanb@google.com, sj@kernel.org, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, muchun.song@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, jannh@google.com, linmiaohe@huawei.com, nao.horiguchi@gmail.com, pfalcato@suse.de, rientjes@google.com, shakeel.butt@linux.dev, riel@surriel.com, harry.yoo@oracle.com, cl@gentwo.org, roman.gushchin@linux.dev, chrisl@kernel.org, kasong@tencent.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, zhengqi.arch@bytedance.com, terry.bowman@amd.com Subject: Re: [LSF/MM/BPF TOPIC][RFC PATCH v4 00/27] Private Memory Nodes (w/ Compressed RAM) Message-ID: References: <20260222084842.1824063-1-gourry@gourry.net> Precedence: bulk X-Mailing-List: linux-trace-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: On Wed, Feb 25, 2026 at 12:40:09PM +0000, Alejandro Lucero Palau wrote: > > > /* This is my memory. There are many like it, but this one is mine. */ > > rc = add_private_memory_driver_managed(nid, start, size, name, flags, > > online_type, private_context); > > > > page = alloc_pages_node(nid, __GFP_PRIVATE, 0); > > > Hi Gregory, > > > I can see the nid param is just a "preferred nid" with alloc pages. Using > __GFP_PRIVATE will restrict the allocation to private nodes but I think the > idea here is: > > > 1) I own this node > > 2) Do not give me memory from another private node but from mine. > > > Should not this be ensure somehow? > A right I set up GFP_PRIVATE for this #define GFP_PRIVATE (__GFP_PRIVATE | __GFP_THISNODE) If your service hides the interface to get to this node behind something it controls, and it doesn't enable things like reclaim/compaction etc, then it's responsible for dealing with an out-of-memory situation. __THISNODE was insufficient alone to allow isolation since it is used in a variety of scenarios around the kernel. v2 or v3 explored that. ~Gregory