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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 8369AC432C3 for ; Wed, 20 Nov 2019 10:42:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 635A122429 for ; Wed, 20 Nov 2019 10:42:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728776AbfKTKmY (ORCPT ); Wed, 20 Nov 2019 05:42:24 -0500 Received: from foss.arm.com ([217.140.110.172]:37092 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728581AbfKTKmY (ORCPT ); Wed, 20 Nov 2019 05:42:24 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 269311FB; Wed, 20 Nov 2019 02:42:23 -0800 (PST) Received: from macbook.cambridge.arm.com (macbook.cambridge.arm.com [10.1.194.51]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 25F2B3F6C4; Wed, 20 Nov 2019 02:42:22 -0800 (PST) From: Dietmar Eggemann To: Atish Patra , Russell King Cc: Sudeep Holla , Morten Rasmussen , Lukasz Luba , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] arm: Fix topology setup in case of CPU hotplug for CONFIG_SCHED_MC Date: Wed, 20 Nov 2019 10:42:12 +0000 Message-Id: <20191120104212.14791-1-dietmar.eggemann@arm.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit ca74b316df96 ("arm: Use common cpu_topology structure and functions.") changed cpu_coregroup_mask() from the ARM32 specific implementation in arch/arm/include/asm/topology.h to the one shared with ARM64 and RISCV in drivers/base/arch_topology.c. Currently on Arm32 (TC2 w/ CONFIG_SCHED_MC) the task scheduler setup code (w/ CONFIG_SCHED_DEBUG) shows this during CPU hotplug: ERROR: groups don't span domain->span It happens to CPUs of the cluster of the CPU which gets hot-plugged out on scheduler domain MC. Turns out that the shared cpu_coregroup_mask() requires that the hot-plugged CPU is removed from the core_sibling mask via remove_cpu_topology(). Otherwise the 'is core_sibling subset of cpumask_of_node()' doesn't work. In this case the task scheduler has to deal with cpumask_of_node instead of core_sibling which is wrong on scheduler domain MC. e.g. CPU3 hot-plugged out on TC2 [cluster0: 0,3-4 cluster1: 1-2]: cpu_coregroup_mask(): CPU3 cpumask_of_node=0-2,4 core_sibling=0,3-4 ^ should be: cpu_coregroup_mask(): CPU3 cpumask_of_node=0-2,4 core_sibling=0,4 Add remove_cpu_topology() to __cpu_disable() to remove the CPU from the topology masks in case of a CPU hotplug out operation. At the same time tweak store_cpu_topology() slightly so it will call update_siblings_masks() in case of CPU hotplug in operation via secondary_start_kernel()->smp_store_cpu_info(). This aligns the Arm32 implementation with the Arm64 one. Fixes: ca74b316df96 ("arm: Use common cpu_topology structure and functions") Signed-off-by: Dietmar Eggemann --- arch/arm/kernel/smp.c | 2 ++ arch/arm/kernel/topology.c | 15 +++++++-------- 2 files changed, 9 insertions(+), 8 deletions(-) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 4b0bab2607e4..139c0d98fa29 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -240,6 +240,8 @@ int __cpu_disable(void) if (ret) return ret; + remove_cpu_topology(cpu); + /* * Take this CPU offline. Once we clear this, we can't return, * and we must not schedule until we're ready to give up the cpu. diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 5b9faba03afb..b37b0a340991 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -196,9 +196,8 @@ void store_cpu_topology(unsigned int cpuid) struct cpu_topology *cpuid_topo = &cpu_topology[cpuid]; unsigned int mpidr; - /* If the cpu topology has been already set, just return */ - if (cpuid_topo->core_id != -1) - return; + if (cpuid_topo->package_id != -1) + goto topology_populated; mpidr = read_cpuid_mpidr(); @@ -231,14 +230,14 @@ void store_cpu_topology(unsigned int cpuid) cpuid_topo->package_id = -1; } - update_siblings_masks(cpuid); - update_cpu_capacity(cpuid); pr_info("CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n", - cpuid, cpu_topology[cpuid].thread_id, - cpu_topology[cpuid].core_id, - cpu_topology[cpuid].package_id, mpidr); + cpuid, cpuid_topo->thread_id, cpuid_topo->core_id, + cpuid_topo->package_id, mpidr); + +topology_populated: + update_siblings_masks(cpuid); } static inline int cpu_corepower_flags(void) -- 2.17.1