Messages in this thread Patch in this message | | | From | Yang Yingliang <> | Subject | [RFC PATCH v4 4/4] arm: fix a migrating irq bug when hotplug cpu | Date | Thu, 17 Sep 2015 13:19:26 +0800 |
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When cpu is disabled, all irqs will be migratged to another cpu. In some cases, a new affinity is different, it needed to be coppied to irq's affinity. But if the type of irq is LPI, it's affinity will not be coppied because of irq_set_affinity's return value. Fix it by using irq_do_set_affinity.
And migrating interrupts is a core code matter, so use the generic function move_irqs() to migrate interrupts in kernel/irq/migration.c.
Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- arch/arm/Kconfig | 1 + arch/arm/include/asm/irq.h | 1 - arch/arm/kernel/irq.c | 62 ---------------------------------------------- arch/arm/kernel/smp.c | 2 +- 4 files changed, 2 insertions(+), 64 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 72ad724..bffba78 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1492,6 +1492,7 @@ config NR_CPUS config HOTPLUG_CPU bool "Support for hot-pluggable CPUs" depends on SMP + select GENERIC_IRQ_MIGRATION help Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu. diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h index be1d07d..882bf98 100644 --- a/arch/arm/include/asm/irq.h +++ b/arch/arm/include/asm/irq.h @@ -24,7 +24,6 @@ #ifndef __ASSEMBLY__ struct irqaction; struct pt_regs; -extern void migrate_irqs(void); extern void asm_do_IRQ(unsigned int, struct pt_regs *); void handle_IRQ(unsigned int, struct pt_regs *); diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 5ff4826..78abea8 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -31,7 +31,6 @@ #include <linux/smp.h> #include <linux/init.h> #include <linux/seq_file.h> -#include <linux/ratelimit.h> #include <linux/errno.h> #include <linux/list.h> #include <linux/kallsyms.h> @@ -136,64 +135,3 @@ int __init arch_probe_nr_irqs(void) return nr_irqs; } #endif - -#ifdef CONFIG_HOTPLUG_CPU -static bool migrate_one_irq(struct irq_desc *desc) -{ - struct irq_data *d = irq_desc_get_irq_data(desc); - const struct cpumask *affinity = irq_data_get_affinity_mask(d); - struct irq_chip *c; - bool ret = false; - - /* - * If this is a per-CPU interrupt, or the affinity does not - * include this CPU, then we have nothing to do. - */ - if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) - return false; - - if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { - affinity = cpu_online_mask; - ret = true; - } - - c = irq_data_get_irq_chip(d); - if (!c->irq_set_affinity) - pr_debug("IRQ%u: unable to set affinity\n", d->irq); - else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret) - cpumask_copy(irq_data_get_affinity_mask(d), affinity); - - return ret; -} - -/* - * The current CPU has been marked offline. Migrate IRQs off this CPU. - * If the affinity settings do not allow other CPUs, force them onto any - * available CPU. - * - * Note: we must iterate over all IRQs, whether they have an attached - * action structure or not, as we need to get chained interrupts too. - */ -void migrate_irqs(void) -{ - unsigned int i; - struct irq_desc *desc; - unsigned long flags; - - local_irq_save(flags); - - for_each_irq_desc(i, desc) { - bool affinity_broken; - - raw_spin_lock(&desc->lock); - affinity_broken = migrate_one_irq(desc); - raw_spin_unlock(&desc->lock); - - if (affinity_broken) - pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n", - i, smp_processor_id()); - } - - local_irq_restore(flags); -} -#endif /* CONFIG_HOTPLUG_CPU */ diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 48185a7..262ead7 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -218,7 +218,7 @@ int __cpu_disable(void) /* * OK - migrate IRQs away from this CPU */ - migrate_irqs(); + move_irqs(); /* * Flush user cache and TLB mappings, and then remove this CPU -- 2.5.0
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