Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753159AbaGVIFN (ORCPT ); Tue, 22 Jul 2014 04:05:13 -0400 Received: from mga02.intel.com ([134.134.136.20]:9426 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750891AbaGVIFH (ORCPT ); Tue, 22 Jul 2014 04:05:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,708,1400050800"; d="scan'208";a="576868560" From: Wanpeng Li To: Cc: Ingo Molnar , Peter Zijlstra , x86@kernel.org, Borislav Petkov , Yasuaki Ishimatsu , David Rientjes , Prarit Bhargava , Steven Rostedt , Jan Kiszka , Toshi Kani , linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH v2] x86, hotplug: fix llc shared map unreleased during cpu hotplug Date: Tue, 22 Jul 2014 16:04:52 +0800 Message-Id: <1406016292-55968-1-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ 220.262093] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 220.262104] IP: [] find_busiest_group+0x2b9/0xa30 [ 220.262111] PGD 5a9d5067 PUD 13067 PMD 0 [ 220.262117] Oops: 0000 [#3] SMP [...] [ 220.262245] Call Trace: [ 220.262252] [] load_balance+0x156/0x980 [ 220.262259] [] ? _raw_spin_unlock_irqrestore+0x2e/0xa0 [ 220.262266] [] idle_balance+0xe3/0x150 [ 220.262270] [] __schedule+0x797/0x8d0 [ 220.262277] [] schedule+0x24/0x70 [ 220.262283] [] schedule_timeout+0x119/0x1f0 [ 220.262294] [] ? lock_timer_base+0x70/0x70 [ 220.262301] [] schedule_timeout_uninterruptible+0x19/0x20 [ 220.262308] [] msleep+0x18/0x20 [ 220.262317] [] lock_device_hotplug_sysfs+0x2a/0x50 [ 220.262323] [] online_store+0x2e/0x80 [ 220.262358] [] dev_attr_store+0x1b/0x20 [ 220.262366] [] sysfs_write_file+0xdd/0x160 [ 220.262377] [] vfs_write+0xc8/0x170 [ 220.262384] [] SyS_write+0x5a/0xa0 [ 220.262388] [] system_call_fastpath+0x16/0x1b Last level cache shared map is built during cpu up and build sched domain routine takes advantage of it to setup sched domain cpu topology, however, llc shared map is unreleased during cpu disable which lead to invalid sched domain cpu topology. This patch fix it by release llc shared map correctly during cpu disable. Signed-off-by: Wanpeng Li --- v1 -> v2: * fix subject line arch/x86/kernel/smpboot.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 5492798..0134ec7 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1292,6 +1292,9 @@ static void remove_siblinginfo(int cpu) for_each_cpu(sibling, cpu_sibling_mask(cpu)) cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling)); + for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) + cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling)); + cpumask_clear(cpu_llc_shared_mask(cpu)); cpumask_clear(cpu_sibling_mask(cpu)); cpumask_clear(cpu_core_mask(cpu)); c->phys_proc_id = 0; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/