Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932489AbdGCOcJ (ORCPT ); Mon, 3 Jul 2017 10:32:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36202 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932518AbdGCNnA (ORCPT ); Mon, 3 Jul 2017 09:43:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhou Chengming , NuoHan Qiao , ak@linux.intel.com, peterz@infradead.org, kan.liang@intel.com, dave.hansen@linux.intel.com, eranian@google.com, davidcc@google.com, guohanjun@huawei.com, Thomas Gleixner , Sasha Levin Subject: [PATCH 4.9 070/172] perf/x86/intel: Handle exclusive threadid correctly on CPU hotplug Date: Mon, 3 Jul 2017 15:34:10 +0200 Message-Id: <20170703133417.516281179@linuxfoundation.org> X-Mailer: git-send-email 2.13.2 In-Reply-To: <20170703133414.260777365@linuxfoundation.org> References: <20170703133414.260777365@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2143 Lines: 64 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhou Chengming [ Upstream commit 4e71de7986386d5fd3765458f27d612931f27f5e ] The CPU hotplug function intel_pmu_cpu_starting() sets cpu_hw_events.excl_thread_id unconditionally to 1 when the shared exclusive counters data structure is already availabe for the sibling thread. This works during the boot process because the first sibling gets threadid 0 assigned and the second sibling which shares the data structure gets 1. But when the first thread of the core is offlined and onlined again it shares the data structure with the second thread and gets exclusive thread id 1 assigned as well. Prevent this by checking the threadid of the already online thread. [ tglx: Rewrote changelog ] Signed-off-by: Zhou Chengming Cc: NuoHan Qiao Cc: ak@linux.intel.com Cc: peterz@infradead.org Cc: kan.liang@intel.com Cc: dave.hansen@linux.intel.com Cc: eranian@google.com Cc: qiaonuohan@huawei.com Cc: davidcc@google.com Cc: guohanjun@huawei.com Link: http://lkml.kernel.org/r/1484536871-3131-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Thomas Gleixner Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/events/intel/core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3164,13 +3164,16 @@ static void intel_pmu_cpu_starting(int c if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) { for_each_cpu(i, topology_sibling_cpumask(cpu)) { + struct cpu_hw_events *sibling; struct intel_excl_cntrs *c; - c = per_cpu(cpu_hw_events, i).excl_cntrs; + sibling = &per_cpu(cpu_hw_events, i); + c = sibling->excl_cntrs; if (c && c->core_id == core_id) { cpuc->kfree_on_online[1] = cpuc->excl_cntrs; cpuc->excl_cntrs = c; - cpuc->excl_thread_id = 1; + if (!sibling->excl_thread_id) + cpuc->excl_thread_id = 1; break; } }