From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757953Ab2AKR2L (ORCPT ); Wed, 11 Jan 2012 12:28:11 -0500 Received: from mga01.intel.com ([192.55.52.88]:28779 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932478Ab2AKRYf (ORCPT ); Wed, 11 Jan 2012 12:24:35 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="106055451" From: "Fenghua Yu" To: "Ingo Molnar" , "Thomas Gleixner" , "H Peter Anvin" , "Linus Torvalds" , "Andrew Morton" , "Asit K Mallick" , "Tony Luck" , "Arjan van de Ven" , "Suresh B Siddha" , "Len Brown" , "Randy Dunlap" , "Srivatsa S. Bhat" , Konrad Rzeszutek Wilk , Peter Zijlstra , "Chen Gong" , "linux-kernel" , "linux-pm" , "x86" Cc: Fenghua Yu Subject: [PATCH v5 04/12] x86/smpboot.c: Don't offline CPU0 if any irq can not be migrated out of it and remove CPU0 check in smp_callin() Date: Wed, 11 Jan 2012 09:04:45 -0800 Message-Id: <1326301493-28760-5-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 1.7.2 In-Reply-To: <1326301493-28760-1-git-send-email-fenghua.yu@intel.com> References: <1326301493-28760-1-git-send-email-fenghua.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Fenghua Yu Don't offline CPU0 if any irq can not be migrated out of it. Call identify_boot_cpu_online() for CPU0 in smp_callin() and continue to online CPU0 in native_cpu_up(). Signed-off-by: Fenghua Yu --- arch/x86/kernel/smpboot.c | 42 +++++++++++++++++++++++++++++++++++------- 1 files changed, 35 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 66d250c..a3c4be3 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -136,8 +136,8 @@ EXPORT_PER_CPU_SYMBOL(cpu_info); atomic_t init_deasserted; /* - * Report back to the Boot Processor. - * Running on AP. + * Report back to the Boot Processor during boot time or to the caller processor + * during CPU online. */ static void __cpuinit smp_callin(void) { @@ -230,6 +230,13 @@ static void __cpuinit smp_callin(void) pr_debug("Stack at about %p\n", &cpuid); /* + * This function won't run on the BSP during boot time. It run + * on BSP only when BSP is offlined and onlined again. + */ + if (cpuid == 0) + identify_boot_cpu_online(); + + /* * This must be done before setting cpu_online_mask * or calling notify_cpu_starting. */ @@ -845,7 +852,7 @@ int __cpuinit native_cpu_up(unsigned int cpu) pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu); - if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid || + if (apicid == BAD_APICID || !physid_isset(apicid, phys_cpu_present_map) || (!x2apic_mode && apicid >= 255)) { printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu); @@ -1291,12 +1298,33 @@ int native_cpu_disable(void) * Perhaps use cpufreq to drop frequency, but that could go * into generic code. * - * We won't take down the boot processor on i386 due to some + * We won't take down the boot processor on x86 if some * interrupts only being able to be serviced by the BSP. - * Especially so if we're not using an IOAPIC -zwane + * Especially so if we're not using an IOAPIC */ - if (cpu == 0) - return -EBUSY; + if (cpu == 0) { + int irq; + struct irq_desc *desc; + struct irq_data *data; + struct irq_chip *chip; + + for_each_irq_desc(irq, desc) { + raw_spin_lock(&desc->lock); + if (!irq_has_action(irq)) { + raw_spin_unlock(&desc->lock); + continue; + } + + data = irq_desc_get_irq_data(desc); + chip = irq_data_get_irq_chip(data); + if (!chip->irq_set_affinity) { + pr_debug("irq%d can't move out of BSP\n", irq); + raw_spin_unlock(&desc->lock); + return -EBUSY; + } + raw_spin_unlock(&desc->lock); + } + } clear_local_APIC(); -- 1.6.0.3