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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 1CDFFC433E1 for ; Fri, 3 Jul 2020 15:57:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF3E620737 for ; Fri, 3 Jul 2020 15:57:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="a8YSI/EH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726669AbgGCP5y (ORCPT ); Fri, 3 Jul 2020 11:57:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726111AbgGCP5x (ORCPT ); Fri, 3 Jul 2020 11:57:53 -0400 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59CE4C061794 for ; Fri, 3 Jul 2020 08:57:53 -0700 (PDT) Received: by mail-lf1-x12e.google.com with SMTP id t74so18795080lff.2 for ; Fri, 03 Jul 2020 08:57:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=nJfTZsg6zGpN4LZZod8fa0dun7XM75S7cDWAFPDQlzE=; b=a8YSI/EHpQyrMqboBcug3Bi3PbNtG8hdkBOtonmFDp4/WYV51C1PhyeogwwCZXzQPv fCyNJn/rKxuxBw1gO8DoX1c1Hui8hifWeN59qkQcvQl+/mNEcW1bTOhZQsxa23bsGlVC cXdLXnsSRmQMuhgUxL9X9ct9jUmCEMDDpan0PjAWmSViLTMrx0YFVU5se+lxFN0M+wQ4 JJlJvpmsOTnSQVm65C5nxQK/LE7Hdhq5+gz/4MStKuNKu7dsmRqW+7zBrdUN308AeN6L z7q7HNRNg/eIiZCCry8hx8kvN5wou4DlQPtFgUnmnBGaxU6GFM7BHacn+clwgHFb9MZB 0Uhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=nJfTZsg6zGpN4LZZod8fa0dun7XM75S7cDWAFPDQlzE=; b=S4hmXAU9J/MI3SQSM14JFA4diRLcE9J3n/C0I7TgJShPrps6pak5wGD4s1hs4ws2Qa X0VLGelmGWocH900Jz9QqqUgvBvXeo9zzQo216GMrDu9SSlEbrO7XXpQLzWpSHBjNMbq yxMvo2DI2KlJ6LMVvwhW/DiUyUXsHM3RhklWM08XZrwZL43XqwH+wudo+YPpoJPRzfAN 9bH2K9LcBqCXdjiQ6gHFwC+MWCQuTWCiSnXDKaystKWF9ThcS/lAWDaRvqMwBBo8jS4Z frFdr1+HJDKU4fiGaaNnWxH49PoPfcKqMGZV01nUmK3kPWViL3zbdiMTTsC/LZxk2UrR 6tsw== X-Gm-Message-State: AOAM533UmGr2EgXGcZSUv1z1slXBgwXt8NOiVsOka+WPUDe1lcxKJZ8Y 9RM5fuPb5i8i9u3cJqZf9YmK/opb03/aaA== X-Google-Smtp-Source: ABdhPJz+VDfZjsli5UxFGTdOGf24yXTHZox6rW9tCpirhNrxUNQKHIiy+mmSmxF/RWSNOhzpLh4wSQ== X-Received: by 2002:a19:8608:: with SMTP id i8mr9811691lfd.54.1593791871508; Fri, 03 Jul 2020 08:57:51 -0700 (PDT) Received: from pc636 (h5ef52e31.seluork.dyn.perspektivbredband.net. [94.245.46.49]) by smtp.gmail.com with ESMTPSA id q2sm4901973ljp.135.2020.07.03.08.57.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Jul 2020 08:57:51 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Fri, 3 Jul 2020 17:57:49 +0200 To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Andrew Morton , Linus Torvalds , GregKroah-Hartmangregkh@linuxfoundation.org, peterz@infradead.org Subject: nr_cpu_ids vs AMD 3970x(32 physical CPUs) Message-ID: <20200703155749.GA6255@pc636> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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, GSI 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:128 nr_node_ids:1 ... [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=128, Nodes=1 [ 0.000000] rcu: RCU restricting CPUs from NR_CPUS=512 to nr_cpu_ids=128. [ 0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=128 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