From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f71.google.com (mail-pl0-f71.google.com [209.85.160.71]) by kanga.kvack.org (Postfix) with ESMTP id 06E1A6B025E for ; Wed, 20 Dec 2017 15:22:27 -0500 (EST) Received: by mail-pl0-f71.google.com with SMTP id 3so8562369plv.17 for ; Wed, 20 Dec 2017 12:22:27 -0800 (PST) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id h1si13449933pld.117.2017.12.20.12.22.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Dec 2017 12:22:26 -0800 (PST) Subject: Re: [PATCH v3 0/3] create sysfs representation of ACPI HMAT References: <20171214021019.13579-1-ross.zwisler@linux.intel.com> <20171214130032.GK16951@dhcp22.suse.cz> <20171218203547.GA2366@linux.intel.com> <20171220181937.GB12236@bombadil.infradead.org> From: Dave Hansen Message-ID: <2da89d31-27a3-34ab-2dbb-92403c8215ec@intel.com> Date: Wed, 20 Dec 2017 12:22:21 -0800 MIME-Version: 1.0 In-Reply-To: <20171220181937.GB12236@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox , Ross Zwisler Cc: Michal Hocko , linux-kernel@vger.kernel.org, "Anaczkowski, Lukasz" , "Box, David E" , "Kogut, Jaroslaw" , "Koss, Marcin" , "Koziej, Artur" , "Lahtinen, Joonas" , "Moore, Robert" , "Nachimuthu, Murugasamy" , "Odzioba, Lukasz" , "Rafael J. Wysocki" , "Rafael J. Wysocki" , "Schmauss, Erik" , "Verma, Vishal L" , "Zheng, Lv" , Andrew Morton , Balbir Singh , Brice Goglin , Dan Williams , Jerome Glisse , John Hubbard , Len Brown , Tim Chen , devel@acpica.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-api@vger.kernel.org, linuxppc-dev@lists.ozlabs.org On 12/20/2017 10:19 AM, Matthew Wilcox wrote: > I don't know what the right interface is, but my laptop has a set of > /sys/devices/system/memory/memoryN/ directories. Perhaps this is the > right place to expose write_bw (etc). Those directories are already too redundant and wasteful. I think we'd really rather not add to them. In addition, it's technically possible to have a memory section span NUMA nodes and have different performance properties, which make it impossible to represent there. In any case, ACPI PXM's (Proximity Domains) are guaranteed to have uniform performance properties in the HMAT, and we just so happen to always create one NUMA node per PXM. So, NUMA nodes really are a good fit. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org