From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751782AbdJXSI0 (ORCPT ); Tue, 24 Oct 2017 14:08:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47686 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751299AbdJXSIR (ORCPT ); Tue, 24 Oct 2017 14:08:17 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 43310C070125 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=prarit@redhat.com From: Prarit Bhargava To: linux-kernel@vger.kernel.org Cc: Prarit Bhargava , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Peter Zijlstra , Andi Kleen , Dave Hansen , Piotr Luc , Kan Liang , Borislav Petkov , Stephane Eranian , Arvind Yadav , Andy Lutomirski , Christian Borntraeger , "Kirill A. Shutemov" , Tom Lendacky , Mathias Krause , Tim Chen , Vitaly Kuznetsov Subject: [PATCH 0/3 v4] Fix panic in logical packages calculation Date: Tue, 24 Oct 2017 14:07:59 -0400 Message-Id: <20171024180802.8422-1-prarit@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 24 Oct 2017 18:08:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A system booted with a small number of cores enabled per package panics because the estimate of __max_logical_packages is too low. This occurs when the total number of active cores across all packages is less than the maximum core count for a single package. Andi noted that the logical_packages calculation wastes 128k on 64-bit x86 systems and posted patches to fix the allocation. His patches result in significant memory size savings, and I have put my fix on top of those patches. Here's an example of the panic: smpboot: Booting Node 1, Processors #1 OK smpboot: Package 1 of CPU 1 exceeds BIOS package data 1. ------------[ cut here ]------------ kernel BUG at arch/x86/kernel/cpu/common.c:1087! invalid opcode: 0000 [#1] SMP Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.0-rc2+ #4 This was tested by dropping the number of active cores across all packages to reproduce the bug above. Additional testing included 2 socket and 4 socket systems and hotplugging entire sockets in different order. Signed-off-by: Prarit Bhargava Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: Peter Zijlstra Cc: Andi Kleen Cc: Dave Hansen Cc: Piotr Luc Cc: Kan Liang Cc: Borislav Petkov Cc: Stephane Eranian Cc: Arvind Yadav Cc: Andy Lutomirski Cc: Christian Borntraeger Cc: "Kirill A. Shutemov" Cc: Tom Lendacky Cc: Mathias Krause Cc: Tim Chen Cc: Vitaly Kuznetsov Andi Kleen (2): perf/x86/intel/uncore: Cache logical pkg id in uncore driver x86/topology: Avoid wasting 128k for package id array Prarit Bhargava (1): x86/smpboot: Fix __max_logical_packages estimate arch/x86/events/intel/uncore.c | 1 + arch/x86/events/intel/uncore.h | 1 + arch/x86/events/intel/uncore_snbep.c | 2 +- arch/x86/include/asm/processor.h | 4 +- arch/x86/kernel/smpboot.c | 137 ++++++++++++----------------------- 5 files changed, 53 insertions(+), 92 deletions(-) -- 2.15.0.rc0.39.g2f0e14e64