Messages in this thread Patch in this message | | | From | "Fenghua Yu" <> | Subject | [PATCH 8/9] x86/smpboot.c: Don't offline BSP if any irq can not be migrated out of it | Date | Fri, 4 Nov 2011 15:04:00 -0700 |
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From: Fenghua Yu <fenghua.yu@intel.com>
Don't offline BSP if any irq can not be migrated out of it.
Call identify_boot_cpu_online() for BSP in smp_callin() and continue to online BSP in native_cpu_up().
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> --- arch/x86/kernel/smpboot.c | 43 ++++++++++++++++++++++++++++++++++++------- 1 files changed, 36 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 9f548cb..83838c5 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) { @@ -224,6 +224,13 @@ static void __cpuinit smp_callin(void) smp_store_cpu_info(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. */ @@ -839,7 +846,7 @@ 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)) { printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu); return -EINVAL; @@ -1283,12 +1290,34 @@ 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 i386 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 + * -original comment from zwane, changed by fyu */ - 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
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