From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [RFC PATCH 00/14] Heterogeneous Memory System (HMS) and hbind() Date: Tue, 4 Dec 2018 13:37:56 -0800 Message-ID: <20163c1e-00f1-7e02-82c0-7730ceabb9f2@intel.com> References: <20181203233509.20671-1-jglisse@redhat.com> <9d745b99-22e3-c1b5-bf4f-d3e83113f57b@intel.com> <20181204184919.GD2937@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181204184919.GD2937@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Jerome Glisse Cc: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, "Rafael J . Wysocki" , Matthew Wilcox , Ross Zwisler , Keith Busch , Dan Williams , Haggai Eran , Balbir Singh , "Aneesh Kumar K . V" , Benjamin Herrenschmidt , Felix Kuehling , Philip Yang , =?UTF-8?Q?Christian_K=c3=b6nig?= , Paul Blinzer , Logan Gunthorpe , John Hubbard , Ralph Campbell List-Id: linux-acpi@vger.kernel.org On 12/4/18 10:49 AM, Jerome Glisse wrote: >> Also, could you add a simple, example program for how someone might use >> this? I got lost in all the new sysfs and ioctl gunk. Can you >> characterize how this would work with the *exiting* NUMA interfaces that >> we have? > That is the issue i can not expose device memory as NUMA node as > device memory is not cache coherent on AMD and Intel platform today. > > More over in some case that memory is not visible at all by the CPU > which is not something you can express in the current NUMA node. Yeah, our NUMA mechanisms are for managing memory that the kernel itself manages in the "normal" allocator and supports a full feature set on. That has a bunch of implications, like that the memory is cache coherent and accessible from everywhere. The HMAT patches only comprehend this "normal" memory, which is why we're extending the existing /sys/devices/system/node infrastructure. This series has a much more aggressive goal, which is comprehending the connections of every memory-target to every memory-initiator, no matter who is managing the memory, who can access it, or what it can be used for. Theoretically, HMS could be used for everything that we're doing with /sys/devices/system/node, as long as it's tied back into the existing NUMA infrastructure _somehow_. Right? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA869C04EB8 for ; Tue, 4 Dec 2018 21:37:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7606020851 for ; Tue, 4 Dec 2018 21:37:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7606020851 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726192AbeLDVh6 (ORCPT ); Tue, 4 Dec 2018 16:37:58 -0500 Received: from mga04.intel.com ([192.55.52.120]:22876 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725899AbeLDVh5 (ORCPT ); Tue, 4 Dec 2018 16:37:57 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Dec 2018 13:37:56 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,315,1539673200"; d="scan'208";a="98653382" Received: from ray.jf.intel.com (HELO [10.7.201.141]) ([10.7.201.141]) by orsmga008.jf.intel.com with ESMTP; 04 Dec 2018 13:37:56 -0800 Subject: Re: [RFC PATCH 00/14] Heterogeneous Memory System (HMS) and hbind() To: Jerome Glisse Cc: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, "Rafael J . Wysocki" , Matthew Wilcox , Ross Zwisler , Keith Busch , Dan Williams , Haggai Eran , Balbir Singh , "Aneesh Kumar K . V" , Benjamin Herrenschmidt , Felix Kuehling , Philip Yang , =?UTF-8?Q?Christian_K=c3=b6nig?= , Paul Blinzer , Logan Gunthorpe , John Hubbard , Ralph Campbell , Michal Hocko , Jonathan Cameron , Mark Hairgrove , Vivek Kini , Mel Gorman , Dave Airlie , Ben Skeggs , Andrea Arcangeli , Rik van Riel , Ben Woodard , linux-acpi@vger.kernel.org References: <20181203233509.20671-1-jglisse@redhat.com> <9d745b99-22e3-c1b5-bf4f-d3e83113f57b@intel.com> <20181204184919.GD2937@redhat.com> From: Dave Hansen Openpgp: preference=signencrypt Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzShEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gPGRhdmVAc3I3MS5uZXQ+wsF7BBMBAgAlAhsDBgsJCAcDAgYVCAIJ CgsEFgIDAQIeAQIXgAUCTo3k0QIZAQAKCRBoNZUwcMmSsMO2D/421Xg8pimb9mPzM5N7khT0 2MCnaGssU1T59YPE25kYdx2HntwdO0JA27Wn9xx5zYijOe6B21ufrvsyv42auCO85+oFJWfE K2R/IpLle09GDx5tcEmMAHX6KSxpHmGuJmUPibHVbfep2aCh9lKaDqQR07gXXWK5/yU1Dx0r VVFRaHTasp9fZ9AmY4K9/BSA3VkQ8v3OrxNty3OdsrmTTzO91YszpdbjjEFZK53zXy6tUD2d e1i0kBBS6NLAAsqEtneplz88T/v7MpLmpY30N9gQU3QyRC50jJ7LU9RazMjUQY1WohVsR56d ORqFxS8ChhyJs7BI34vQusYHDTp6PnZHUppb9WIzjeWlC7Jc8lSBDlEWodmqQQgp5+6AfhTD kDv1a+W5+ncq+Uo63WHRiCPuyt4di4/0zo28RVcjtzlGBZtmz2EIC3vUfmoZbO/Gn6EKbYAn rzz3iU/JWV8DwQ+sZSGu0HmvYMt6t5SmqWQo/hyHtA7uF5Wxtu1lCgolSQw4t49ZuOyOnQi5 f8R3nE7lpVCSF1TT+h8kMvFPv3VG7KunyjHr3sEptYxQs4VRxqeirSuyBv1TyxT+LdTm6j4a mulOWf+YtFRAgIYyyN5YOepDEBv4LUM8Tz98lZiNMlFyRMNrsLV6Pv6SxhrMxbT6TNVS5D+6 UorTLotDZKp5+M7BTQRUY85qARAAsgMW71BIXRgxjYNCYQ3Xs8k3TfAvQRbHccky50h99TUY sqdULbsb3KhmY29raw1bgmyM0a4DGS1YKN7qazCDsdQlxIJp9t2YYdBKXVRzPCCsfWe1dK/q 66UVhRPP8EGZ4CmFYuPTxqGY+dGRInxCeap/xzbKdvmPm01Iw3YFjAE4PQ4hTMr/H76KoDbD cq62U50oKC83ca/PRRh2QqEqACvIH4BR7jueAZSPEDnzwxvVgzyeuhwqHY05QRK/wsKuhq7s UuYtmN92Fasbxbw2tbVLZfoidklikvZAmotg0dwcFTjSRGEg0Gr3p/xBzJWNavFZZ95Rj7Et db0lCt0HDSY5q4GMR+SrFbH+jzUY/ZqfGdZCBqo0cdPPp58krVgtIGR+ja2Mkva6ah94/oQN lnCOw3udS+Eb/aRcM6detZr7XOngvxsWolBrhwTQFT9D2NH6ryAuvKd6yyAFt3/e7r+HHtkU kOy27D7IpjngqP+b4EumELI/NxPgIqT69PQmo9IZaI/oRaKorYnDaZrMXViqDrFdD37XELwQ gmLoSm2VfbOYY7fap/AhPOgOYOSqg3/Nxcapv71yoBzRRxOc4FxmZ65mn+q3rEM27yRztBW9 AnCKIc66T2i92HqXCw6AgoBJRjBkI3QnEkPgohQkZdAb8o9WGVKpfmZKbYBo4pEAEQEAAcLB XwQYAQIACQUCVGPOagIbDAAKCRBoNZUwcMmSsJeCEACCh7P/aaOLKWQxcnw47p4phIVR6pVL e4IEdR7Jf7ZL00s3vKSNT+nRqdl1ugJx9Ymsp8kXKMk9GSfmZpuMQB9c6io1qZc6nW/3TtvK pNGz7KPPtaDzvKA4S5tfrWPnDr7n15AU5vsIZvgMjU42gkbemkjJwP0B1RkifIK60yQqAAlT YZ14P0dIPdIPIlfEPiAWcg5BtLQU4Wg3cNQdpWrCJ1E3m/RIlXy/2Y3YOVVohfSy+4kvvYU3 lXUdPb04UPw4VWwjcVZPg7cgR7Izion61bGHqVqURgSALt2yvHl7cr68NYoFkzbNsGsye9ft M9ozM23JSgMkRylPSXTeh5JIK9pz2+etco3AfLCKtaRVysjvpysukmWMTrx8QnI5Nn5MOlJj 1Ov4/50JY9pXzgIDVSrgy6LYSMc4vKZ3QfCY7ipLRORyalFDF3j5AGCMRENJjHPD6O7bl3Xo 4DzMID+8eucbXxKiNEbs21IqBZbbKdY1GkcEGTE7AnkA3Y6YB7I/j9mQ3hCgm5muJuhM/2Fr OPsw5tV/LmQ5GXH0JQ/TZXWygyRFyyI2FqNTx4WHqUn3yFj8rwTAU1tluRUYyeLy0ayUlKBH ybj0N71vWO936MqP6haFERzuPAIpxj2ezwu0xb1GjTk4ynna6h5GjnKgdfOWoRtoWndMZxbA z5cecg== Message-ID: <20163c1e-00f1-7e02-82c0-7730ceabb9f2@intel.com> Date: Tue, 4 Dec 2018 13:37:56 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181204184919.GD2937@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/4/18 10:49 AM, Jerome Glisse wrote: >> Also, could you add a simple, example program for how someone might use >> this? I got lost in all the new sysfs and ioctl gunk. Can you >> characterize how this would work with the *exiting* NUMA interfaces that >> we have? > That is the issue i can not expose device memory as NUMA node as > device memory is not cache coherent on AMD and Intel platform today. > > More over in some case that memory is not visible at all by the CPU > which is not something you can express in the current NUMA node. Yeah, our NUMA mechanisms are for managing memory that the kernel itself manages in the "normal" allocator and supports a full feature set on. That has a bunch of implications, like that the memory is cache coherent and accessible from everywhere. The HMAT patches only comprehend this "normal" memory, which is why we're extending the existing /sys/devices/system/node infrastructure. This series has a much more aggressive goal, which is comprehending the connections of every memory-target to every memory-initiator, no matter who is managing the memory, who can access it, or what it can be used for. Theoretically, HMS could be used for everything that we're doing with /sys/devices/system/node, as long as it's tied back into the existing NUMA infrastructure _somehow_. Right?