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 6AE78407CEF for ; Wed, 17 Jun 2026 14:03:52 +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=1781705033; cv=none; b=IoDOrwpZNT9WPfDVgiBuD7KHvAuXyfMp0gpYdhAI7HDoqe0TNMgR+oMb25ReFsYkEk8hwdZhHK+BQUiIbzA32to9Cq/CV3mhL63FHLQQ2H3ScCEmTE8Cd5wJDZjfQUkr8SKeaAZOBLEsZFVBYZWnyYmSfnrrGutcOM20zTmF6Ns= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781705033; c=relaxed/simple; bh=95TSTVQlWc9XEmLQ5CRQKISimsK3+z9mzOJYVfT8u2w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XiJRDw+wcAifpKCGK/r199tqZ/oCTQafPpugzSeE1gWPyX+KleCNBilglxo7pGnKCeLBVN+UuBMzftK2q6raVF7oU4dW16cxF6tD0tMaI9uUzbqVsLhRseHiuoDMcVegfhCtpRKCVCXNseJEbFGF8LgkV7fdAjK7+UEr5dG3mTQ= 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=VKY/uljc; 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="VKY/uljc" Received: by mail-qt1-f172.google.com with SMTP id d75a77b69052e-516d0db9372so48670201cf.2 for ; Wed, 17 Jun 2026 07:03:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1781705031; x=1782309831; 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=21pxQXdsUMGW+bGknxxPyRxRyaJDV62jMRhp5DnWHkk=; b=VKY/uljcfnKh99zo5ySSTpXVX7+PQXcN9dydeIP3wAjLilTe7GyGtIKsWKRXaqjfcj V60zh+FXk43C01MtPyaBVrkkdpfCl05MVgB8i39okjylUDiUNSlSKaXk2ht/jc3PilPZ HhjWrtpiTDxksxAS3zbmbcxNEToz6Ha9CTeE3/wQBXkraKZvoeYV3B9KQ5R6VSzel+xv AdZ6a5EFmVMuU9exqmP7Cb3moiTHWGs8es23xSFCEbinplwlXICueJo9ReoXUb2Ee4nR 1tRIZrraIrLJCu/UJBEc9RMu9dylL1GP0EbKXIj5hprozLZDygg1KuOwmHEoAInY5eOX yThQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781705031; x=1782309831; 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=21pxQXdsUMGW+bGknxxPyRxRyaJDV62jMRhp5DnWHkk=; b=ctV2ebZ1iJVYdMYsK4IpuEKcF50OK4mhp2fNPrpCsIgE9eV6kGlMmRRO5H6e43ATAG p3AIZ9g1EDomtdIzMzjayB7KbvO/eBNeD2cKe9z9BlR1DLFddXnkMuzQJxapOXqjA5YG Mb9eYdamZyDKtF2atPvhFm5o3xozK6L/5IuJabOmjumhnHC+UDJYhRjyxH1IYkwXKAGf IigO68Lprn349kd54mXmjukf7w4R5Qok94lKtyZ53u6d/hPWt5S0/8f0HGzPxm/dvS1s 0yDfFBCYJ3/QcImsKQa3GCxQw+KS5zsO8Cg9VqiBiXcgR6QiQBiy99fo/z12ouJnncmU E5oQ== X-Forwarded-Encrypted: i=1; AFNElJ/H7+xsW1eBNT0wWgdemZoKeQF1m1EsVTbQiTjIXo5ji3w2fKBBHo56MvlMbV3ijekB2G5M/Je/6BOeXF0=@vger.kernel.org X-Gm-Message-State: AOJu0YwaUW7BTwqbYd2YJPOIvjQDz+k4C2Q7qDy6/7uQ4FbsUpWmLYLv eP3TfY5j2jOZDxySkVhdzh1Lu1815nnr9XEA7ufsR928NMkKGb0pwjrQ8N72FRjj9P0= X-Gm-Gg: Acq92OHRmtdsRCNnhjxJnNT0ENWfBG4y/JJw8vXvYTTZTVsSHC9diq4s/pJo8wshA7W YfmZCHCF+AsEtwBVkuPOEwot5yCEChyDKeplgp4kgPK5olquID01IP2cNV2vQs73s4kL2YF5XWV VGU2DU1T0vw1V9LWsGOA/M9BjnQCIAru/4NDcGL6r4EVQWpx8RypYHBhEhdIcsPobWQl9CBHJN5 IlNtXoj1vdGrUSEQ6Li7uVqc6ZTR439Eo6IubUZZ16V2Z61m/LfY/m+CHlgasj6olcQDrLXP8b6 MWNuOEzKyUf7NP9T96goAVrrFW9PbotwsHTPITat9rHBG4nGDsJ7IPeDYPL53rev/zGc19WoFCV DZeXwv/pHzrSftjFal+T2vW4pJv5XsNIYNx6ygXfPPkkKqTWRSja9TnG61MSr4TZksePfOwEQIG SSDYd1s9iqkJ1aa/BMsJhQ X-Received: by 2002:a05:622a:4a89:b0:517:82a1:adf1 with SMTP id d75a77b69052e-519a8de2756mr65756641cf.15.1781705031230; Wed, 17 Jun 2026 07:03:51 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F ([2620:10d:c091:500::3:ce0d]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-51955b271fbsm134106091cf.22.2026.06.17.07.03.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jun 2026 07:03:50 -0700 (PDT) Date: Wed, 17 Jun 2026 10:03:46 -0400 From: Gregory Price To: Balbir Singh Cc: "David Hildenbrand (Arm)" , 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, 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-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, Jun 17, 2026 at 02:02:47PM +1000, Balbir Singh wrote: > On Wed, Jun 10, 2026 at 12:37:34PM -0400, Gregory Price wrote: > > On Wed, Jun 10, 2026 at 05:00:33PM +0200, David Hildenbrand (Arm) wrote: > > > On 6/10/26 12:41, Gregory Price wrote: > > > > On Wed, Jun 03, 2026 at 03:00:01PM +1000, Balbir Singh wrote: > > > > > > > > For mm/slub.c we can choose to do one of thwo things > > > > 1) 100% refuse slab allocations on private nodes, i.e.: > > > > kmalloc_node(..., private_nid, __GFP_THISNODE) > > > > And will fail (return NULL). > > > > Doesn't this iterate through N_MEMORY only? N_MEMORY_PRIVATE should not > be in the regular for_each(...) loops > If a node is in neither FALLBACK nor NOFALLBACK - it is *completely* unreachable in the current page allocator. Next RFC I've reduced this to create a ZONELIST_PRIVATE separate from the ZONELIST_FALLBACK and ZONELIST_NOFALLBACK, and an explicit folio allocation interface that selects which fallback list to use. the feedback in the past week has been helpful in honing in on a solution that I think is generalizable. Have just been taking the time to test various behaviors to make sure I haven't been regressing any userland API/ABIs (mbind, mempolicy, etc). ~Gregory