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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 1707EC43331 for ; Wed, 13 Nov 2019 13:57:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9FE22245C for ; Wed, 13 Nov 2019 13:57:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727682AbfKMN5a (ORCPT ); Wed, 13 Nov 2019 08:57:30 -0500 Received: from mga11.intel.com ([192.55.52.93]:50077 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726190AbfKMN53 (ORCPT ); Wed, 13 Nov 2019 08:57:29 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Nov 2019 05:57:28 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,300,1569308400"; d="scan'208";a="194675312" Received: from rcao-mobl3.ccr.corp.intel.com (HELO [10.249.174.53]) ([10.249.174.53]) by orsmga007.jf.intel.com with ESMTP; 13 Nov 2019 05:57:25 -0800 Subject: Re: [PATCH V5 1/4] ACPI: Support Generic Initiator only domains To: Jonathan Cameron , Dan Williams Cc: Linux MM , Linux ACPI , Linux Kernel Mailing List , Linux ARM , X86 ML , Keith Busch , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , "Rafael J . Wysocki" , Linuxarm , Andrew Morton References: <20191004114330.104746-1-Jonathan.Cameron@huawei.com> <20191004114330.104746-2-Jonathan.Cameron@huawei.com> <20191113094742.00000dc4@huawei.com> From: Tao Xu Message-ID: <77b6a6e8-9d44-1e1c-3bf0-a8d04833598d@intel.com> Date: Wed, 13 Nov 2019 21:57:24 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: <20191113094742.00000dc4@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On 11/13/2019 5:47 PM, Jonathan Cameron wrote: > On Tue, 12 Nov 2019 09:55:17 -0800 > Dan Williams wrote: > >> [ add Tao Xu ] >> >> On Fri, Oct 4, 2019 at 4:45 AM Jonathan Cameron >> wrote: >>> >>> Generic Initiators are a new ACPI concept that allows for the >>> description of proximity domains that contain a device which >>> performs memory access (such as a network card) but neither >>> host CPU nor Memory. >>> >>> This patch has the parsing code and provides the infrastructure >>> for an architecture to associate these new domains with their >>> nearest memory processing node. >> >> Thanks for this Jonathan. May I ask how this was tested? Tao has been >> working on qemu support for HMAT [1]. I have not checked if it already >> supports generic initiator entries, but it would be helpful to include >> an example of how the kernel sees these configurations in practice. >> >> [1]: http://patchwork.ozlabs.org/cover/1096737/ > > Tested against qemu with SRAT and SLIT table overrides from an > initrd to actually create the node and give it distances > (those all turn up correctly in the normal places). DSDT override > used to move an emulated network card into the GI numa node. That > currently requires the PCI patch referred to in the cover letter. > On arm64 tested both on qemu and real hardware (overrides on tables > even for real hardware as I can't persuade our BIOS team to implement > Generic Initiators until an OS is actually using them.) > > Main real requirement is memory allocations then occur from one of > the nodes at the minimal distance when you are do a devm_ allocation > from a device assigned. Also need to be able to query the distances > to allow load balancing etc. All that works as expected. > > It only has a fairly tangential connection to HMAT in that HMAT > can provide information on GI nodes. Given HMAT code is quite happy > with memoryless nodes anyway it should work. QEMU doesn't currently > have support to create GI SRAT entries let alone HMAT using them. > > Whilst I could look at adding such support to QEMU, it's not > exactly high priority to emulate something we can test easily > by overriding the tables before the kernel reads them. > > I'll look at how hard it is to build an HMAT tables for my test > configs based on the ones I used to test your HMAT patches a while > back. Should be easy if tedious. > > Jonathan > Indeed, HMAT can support Generic Initiator, but as far as I know, QEMU only can emulate a node with cpu and memory, or memory-only. Even if we assign a node with cpu only, qemu will raise error. Considering compatibility, there are lots of work to do for QEMU if we change NUMA or SRAT table.