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_2 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 5724EC17442 for ; Wed, 13 Nov 2019 09:48:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3708020818 for ; Wed, 13 Nov 2019 09:48:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727445AbfKMJsA (ORCPT ); Wed, 13 Nov 2019 04:48:00 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:43040 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727674AbfKMJsA (ORCPT ); Wed, 13 Nov 2019 04:48:00 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 6CD6BC08E7C566C8E8DB; Wed, 13 Nov 2019 17:47:57 +0800 (CST) Received: from localhost (10.202.226.61) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.439.0; Wed, 13 Nov 2019 17:47:49 +0800 Date: Wed, 13 Nov 2019 09:47:42 +0000 From: Jonathan Cameron To: Dan Williams CC: Linux MM , Linux ACPI , Linux Kernel Mailing List , Linux ARM , X86 ML , "Keith Busch" , =?ISO-8859-1?Q?J=E9r=F4me?= Glisse , "Rafael J . Wysocki" , Linuxarm , Andrew Morton , Tao Xu Subject: Re: [PATCH V5 1/4] ACPI: Support Generic Initiator only domains Message-ID: <20191113094742.00000dc4@huawei.com> In-Reply-To: References: <20191004114330.104746-1-Jonathan.Cameron@huawei.com> <20191004114330.104746-2-Jonathan.Cameron@huawei.com> Organization: Huawei X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.61] X-CFilter-Loop: Reflected Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org 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