From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 84D462218E92B for ; Fri, 22 Dec 2017 21:10:07 -0800 (PST) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vBN5EDdY091742 for ; Sat, 23 Dec 2017 00:14:57 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0a-001b2d01.pphosted.com with ESMTP id 2f19yntadg-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sat, 23 Dec 2017 00:14:57 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 23 Dec 2017 05:14:54 -0000 Subject: Re: [PATCH v3 0/3] create sysfs representation of ACPI HMAT References: <20171214021019.13579-1-ross.zwisler@linux.intel.com> <2d6420f7-0a95-adfe-7390-a2aea4385ab2@linux.vnet.ibm.com> <5d7df981-69c2-e371-f48d-13c418fff134@intel.com> From: Anshuman Khandual Date: Sat, 23 Dec 2017 10:44:34 +0530 MIME-Version: 1.0 In-Reply-To: <5d7df981-69c2-e371-f48d-13c418fff134@intel.com> Message-Id: <3bffaacf-e927-fb06-4dd0-3821f6f82dad@linux.vnet.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dave Hansen , Anshuman Khandual , Ross Zwisler , linux-kernel@vger.kernel.org Cc: "Box, David E" , linux-mm@kvack.org, "Zheng, Lv , linux-nvdimm@lists.01.org, Rafael J. Wysocki" , Anaczkowski,, Robert, Lukasz, "Erik , Len Brown" , John Hubbard , Jerome Glisse , devel@acpica.org, Kogut,, "Marcin , Brice Goglin" , "Nachimuthu, Murugasamy , Rafael J. Wysocki" , Koziej,, "Joonas , Andrew Morton , Tim Chen" List-ID: On 12/22/2017 10:43 PM, Dave Hansen wrote: > On 12/21/2017 07:09 PM, Anshuman Khandual wrote: >> I had presented a proposal for NUMA redesign in the Plumbers Conference this >> year where various memory devices with different kind of memory attributes >> can be represented in the kernel and be used explicitly from the user space. >> Here is the link to the proposal if you feel interested. The proposal is >> very intrusive and also I dont have a RFC for it yet for discussion here. > I think that's the best reason to "re-use NUMA" for this: it's _not_ > intrusive. > > Also, from an x86 perspective, these HMAT systems *will* be out there. > Old versions of Linux *will* see different types of memory as separate > NUMA nodes. So, if we are going to do something different, it's going > to be interesting to un-teach those systems about using the NUMA APIs > for this. That ship has sailed. I understand the need to fetch these details from ACPI/DT for applications to target these distinct memory only NUMA nodes. This can be done by parsing from platform specific values from /proc/acpi/ or /proc/device-tree/ interfaces. This can be a short term solution before NUMA redesign can be figured out. But adding generic devices like "hmat" in the /sys/devices/ path which will be locked for good, seems problematic. _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm