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=-2.5 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 B8E50C433DF for ; Fri, 3 Jul 2020 19:05:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 89DD120782 for ; Fri, 3 Jul 2020 19:05:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89DD120782 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=sony.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 211458D0060; Fri, 3 Jul 2020 15:05:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1BFEB8D0030; Fri, 3 Jul 2020 15:05:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0D6DB8D0060; Fri, 3 Jul 2020 15:05:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0020.hostedemail.com [216.40.44.20]) by kanga.kvack.org (Postfix) with ESMTP id ECD3F8D0030 for ; Fri, 3 Jul 2020 15:05:16 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id B3A9E582B for ; Fri, 3 Jul 2020 19:05:16 +0000 (UTC) X-FDA: 76997692632.26.sail40_5d0644326e94 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id 88CBF1804B66E for ; Fri, 3 Jul 2020 19:05:16 +0000 (UTC) X-HE-Tag: sail40_5d0644326e94 X-Filterd-Recvd-Size: 2840 Received: from SELDSEGREL01.sonyericsson.com (seldsegrel01.sonyericsson.com [37.139.156.29]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Fri, 3 Jul 2020 19:05:15 +0000 (UTC) Subject: Re: nr_cpu_ids vs AMD 3970x(32 physical CPUs) To: Uladzislau Rezki , , CC: Andrew Morton , Linus Torvalds , , References: <20200703155749.GA6255@pc636> From: peter enderborg Message-ID: <8a2a55e6-6087-e4bf-3d35-ed4b4c216369@sony.com> Date: Fri, 3 Jul 2020 21:05:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200703155749.GA6255@pc636> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Language: en-GB X-SEG-SpamProfiler-Analysis: v=2.3 cv=CszBjUwD c=1 sm=1 tr=0 a=Jtaq2Av1iV2Yg7i8w6AGMw==:117 a=IkcTkHD0fZMA:10 a=_RQrkK6FrEwA:10 a=zQO6xEfzLkKbw6bwTKUA:9 a=0OkEAe7UqRvhMRmr:21 a=-cKQYqgAhFfF71hO:21 a=QEXdDO2ut3YA:10 X-SEG-SpamProfiler-Score: 0 X-Rspamd-Queue-Id: 88CBF1804B66E X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 7/3/20 5:57 PM, Uladzislau Rezki wrote: > Hello, folk. > > I have a system based on AMD 3970x CPUs. It has 32 physical cores > and 64 threads. It seems that "nr_cpu_ids" variable is not correctly > set on latest 5.8-rc3 kernel. Please have a look below on dmesg output: > > > urezki@pc638:~$ sudo dmesg | grep 128 > [ 0.000000] IOAPIC[0]: apic_id 128, version 33, address 0xfec00000, GS= I 0-23 > [ 0.000000] smpboot: Allowing 128 CPUs, 64 hotplug CPUs > [ 0.000000] setup_percpu: NR_CPUS:512 nr_cpumask_bits:512 nr_cpu_ids:1= 28 nr_node_ids:1 My 3950 do [=C2=A0=C2=A0=C2=A0 0.005271] ACPI: SSDT 0x00000000CA1F5000 0003F1 (v02 ALA= SKA CPUSSDT=C2=A0 01072009 AMI=C2=A0 01072009) [=C2=A0=C2=A0=C2=A0 0.108266] smpboot: Allowing 32 CPUs, 0 hotplug CPUs [=C2=A0=C2=A0=C2=A0 0.111384] setup_percpu: NR_CPUS:8192 nr_cpumask_bits:32= nr_cpu_ids:32 nr_node_ids:1 (Fedora F32=C2=A0 5.6.18-300) What motherboard and BIOs do you use? > ... > [ 0.000000] SLUB: HWalign=3D64, Order=3D0-3, MinObjects=3D0, CPUs=3D12= 8, Nodes=3D1 > [ 0.000000] rcu: RCU restricting CPUs from NR_CPUS=3D512 to nr_cpu= _ids=3D128. > [ 0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=3D16, nr_cpu_i= ds=3D128 > urezki@pc638:~$ > > > For example SLUB thinks that it deals with 128 CPUs in the system what is > wrong if i do not miss something. Since nr_cpu_ids is broken(?), thus the > "cpu_possible_mask" does not correspond to reality as well. > > Any thoughts? > > Thanks! > > -- > Vlad Rezki