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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 5BED5C433E0 for ; Fri, 12 Mar 2021 10:04:37 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8328E65004 for ; Fri, 12 Mar 2021 10:04:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8328E65004 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4DxhHl0VX1z3dST for ; Fri, 12 Mar 2021 21:04:35 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kaod.org (client-ip=188.165.45.220; helo=5.mo52.mail-out.ovh.net; envelope-from=clg@kaod.org; receiver=) X-Greylist: delayed 166810 seconds by postgrey-1.36 at boromir; Fri, 12 Mar 2021 21:04:06 AEDT Received: from 5.mo52.mail-out.ovh.net (5.mo52.mail-out.ovh.net [188.165.45.220]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4DxhHB21V0z3d3y for ; Fri, 12 Mar 2021 21:04:05 +1100 (AEDT) Received: from mxplan5.mail.ovh.net (unknown [10.108.16.128]) by mo52.mail-out.ovh.net (Postfix) with ESMTPS id C224D24BF63; Fri, 12 Mar 2021 10:53:59 +0100 (CET) Received: from kaod.org (37.59.142.105) by DAG4EX1.mxp5.local (172.16.2.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Fri, 12 Mar 2021 10:53:55 +0100 Authentication-Results: garm.ovh; auth=pass (GARM-105G006feddd577-92b5-4852-9f7d-abacc7bd9cf4, 795EE61F3CDF5270877287A62BE336BF03444C93) smtp.auth=clg@kaod.org X-OVh-ClientIp: 86.201.91.229 Subject: Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property To: David Gibson References: <20210303174857.1760393-1-clg@kaod.org> <20210303174857.1760393-2-clg@kaod.org> <20210308181359.789c143b@bahia.lan> <8dd98e22-1f10-e87b-3fe3-e786bc9a8d71@kaod.org> <3180b5c6-e61f-9c5f-3c80-f10e69dc5785@linux.ibm.com> <92edbc26-4cb5-6e2f-00ff-43a3dca43759@kaod.org> <20210312125527.61bc269c@yekko.fritz.box> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= Message-ID: <4effbb5e-6f08-03bf-cea0-60c986175668@kaod.org> Date: Fri, 12 Mar 2021 10:53:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210312125527.61bc269c@yekko.fritz.box> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [37.59.142.105] X-ClientProxiedBy: DAG5EX2.mxp5.local (172.16.2.42) To DAG4EX1.mxp5.local (172.16.2.31) X-Ovh-Tracer-GUID: 847daada-19e1-4769-8e73-38e32e2d5bc4 X-Ovh-Tracer-Id: 4194821581489671017 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledruddvvddgtdelucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepuffvfhfhkffffgggjggtgfhisehtkeertddtfeejnecuhfhrohhmpeevrogurhhitggpnfgvpgfiohgrthgvrhcuoegtlhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepgeehvefffefhtdduieejheejleefieeuieeuvedvgfeiteeuvdetheduffehgeevnecuffhomhgrihhnpehrvgguhhgrthdrtghomhenucfkpheptddrtddrtddrtddpfeejrdehledrudegvddruddtheenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhhouggvpehsmhhtphdqohhuthdphhgvlhhopehmgihplhgrnhehrdhmrghilhdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomheptghlgheskhgrohgurdhorhhgpdhrtghpthhtohepghhrohhugheskhgrohgurdhorhhg X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Daniel Henrique Barboza , Greg Kurz , QEMU Developers , "list@suse.de:PowerPC" , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 3/12/21 2:55 AM, David Gibson wrote: > On Tue, 9 Mar 2021 18:26:35 +0100 > Cédric Le Goater wrote: > >> On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote: >>> >>> >>> On 3/9/21 12:33 PM, Cédric Le Goater wrote: >>>> On 3/8/21 6:13 PM, Greg Kurz wrote: >>>>> On Wed, 3 Mar 2021 18:48:50 +0100 >>>>> Cédric Le Goater wrote: >>>>> >>>>>> The 'chip_id' field of the XIVE CPU structure is used to choose a >>>>>> target for a source located on the same chip when possible. This field >>>>>> is assigned on the PowerNV platform using the "ibm,chip-id" property >>>>>> on pSeries under KVM when NUMA nodes are defined but it is undefined >>>>> >>>>> This sentence seems to have a syntax problem... like it is missing an >>>>> 'and' before 'on pSeries'. >>>> >>>> ah yes, or simply a comma. >>>> >>>>>> under PowerVM. The XIVE source structure has a similar field >>>>>> 'src_chip' which is only assigned on the PowerNV platform. >>>>>> >>>>>> cpu_to_node() returns a compatible value on all platforms, 0 being the >>>>>> default node. It will also give us the opportunity to set the affinity >>>>>> of a source on pSeries when we can localize them. >>>>>> >>>>> >>>>> IIUC this relies on the fact that the NUMA node id is == to chip id >>>>> on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable >>>>> with this change. >>>> >>>> Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall >>>> H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel >>>> in Cc:) >> [...] >>>> >>>> On PowerNV, Linux uses "ibm,associativity" property of the CPU to find >>>> the node id. This value is built from the chip id in OPAL, so the >>>> value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id" >>>> property are unlikely to be different. >>>> >>>> cpu_to_node(cpu) is used in many places to allocate the structures >>>> locally to the owning node. XIVE is not an exception (see below in the >>>> same patch), it is better to be consistent and get the same information >>>> (node id) using the same routine. >>>> >>>> >>>> In Linux, "ibm,chip-id" is only used in low level PowerNV drivers : >>>> LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot >>>> unifies the controllers of the system to only expose one the OS. This >>>> is problematic and should be changed but it's another topic. >>>> >>>> >>>>> On the other hand, you have the pSeries case under PowerVM that >>>>> doesn't xc->chip_id, which isn't passed to any hcall AFAICT. >>>> >>>> yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning >>>> under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid >>>> chip id. >>>> >>>> QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not >>>> always correct btw) >>> >>> >>> If you have a way to reliably reproduce this, let me know and I'll fix it >>> up in QEMU. >> >> with : >> >> -smp 4,cores=1,maxcpus=8 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 >> >> # dmesg | grep numa >> [ 0.013106] numa: Node 0 CPUs: 0-1 >> [ 0.013136] numa: Node 1 CPUs: 2-3 >> >> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id >> ibm,chip-id = <0x01>; >> ibm,chip-id = <0x02>; >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x03>; >> >> with : >> >> -smp 4,cores=4,maxcpus=8,threads=1 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 >> >> # dmesg | grep numa >> [ 0.013106] numa: Node 0 CPUs: 0-1 >> [ 0.013136] numa: Node 1 CPUs: 2-3 >> >> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x00>; >> >> I think we should simply remove "ibm,chip-id" since it's not used and >> not in the PAPR spec. > > As I mentioned to Daniel on our call this morning, oddly it *does* > appear to be used in the RHEL kernel, even though that's 4.18 based. > This patch seems to have caused a minor regression; not in the > identification of NUMA nodes, but in the number of sockets shown be > lscpu, etc. See https://bugzilla.redhat.com/show_bug.cgi?id=1934421 > for more information. Yes. The property "ibm,chip-id" is wrongly calculated in QEMU. If we remove it, we get with 4.18.0-295.el8.ppc64le or 5.12.0-rc2 : [root@localhost ~]# lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 4 Core(s) per socket: 16 Socket(s): 2 NUMA node(s): 2 Model: 2.2 (pvr 004e 1202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: KVM Virtualization type: para L1d cache: 32K L1i cache: 32K NUMA node0 CPU(s): 0-63 NUMA node1 CPU(s): 64-127 [root@localhost ~]# grep . /sys/devices/system/cpu/*/topology/physical_package_id /sys/devices/system/cpu/cpu0/topology/physical_package_id:-1 /sys/devices/system/cpu/cpu100/topology/physical_package_id:-1 /sys/devices/system/cpu/cpu101/topology/physical_package_id:-1 /sys/devices/system/cpu/cpu102/topology/physical_package_id:-1 /sys/devices/system/cpu/cpu103/topology/physical_package_id:-1 .... "ibm,chip-id" is still being used on some occasion on pSeries machines. This is wrong :/ The problem is : #define topology_physical_package_id(cpu) (cpu_to_chip_id(cpu)) We should be using cpu_to_node(). C. > > Since the value was used by some PAPR kernels - even if they shouldn't > have - I think we should only remove this for newer machine types. We > also need to check what we're not supplying that the guest kernel is > showing a different number of sockets than specified on the qemu > command line. > >> >> Thanks, >> >> C. >> >> >> >> [...] >> [...] >> [...] >> [...] >> [...] >> [...] >> [...] >> [...] >> [...] >> > >