Hi Thomas, On 23/02/14 21:40, Thomas Gleixner wrote: > There is no point in having an incomplete copy of irq_set_affinity() > for the hotplug irq migration code.
That sounds reasonable, but when I gave it a try I started getting warnings on the log after offlining one cpu then the other: META213-Thread0 DSP [LogF] IRQ13 no longer affine to CPU1 META213-Thread0 DSP [LogF] IRQ14 no longer affine to CPU1 META213-Thread0 DSP [LogF] IRQ15 no longer affine to CPU1 META213-Thread0 DSP [LogF] IRQ18 no longer affine to CPU1 META213-Thread0 DSP [LogF] IRQ29 no longer affine to CPU1 META213-Thread0 DSP [LogF] IRQ30 no longer affine to CPU1 META213-Thread0 DSP [LogF] IRQ31 no longer affine to CPU1 It appears that the irq affinities weren't getting modified previously, whereas now irq_do_set_affinity() does do cpumask_copy(data->affinity, mask). Once all CPUs have been offlined at least once you get those spurious messages even though the IRQ affinities haven't been explicitly limited by anything. I wonder if the stored affinity should really be altered in this case? Cheers James > > Use the core function instead and while at it switch to > for_each_active_irq() > > Signed-off-by: Thomas Gleixner <t...@linutronix.de> > Cc: James Hogan <james.ho...@imgtec.com> > Cc: metag <linux-metag@vger.kernel.org> > --- > arch/metag/kernel/irq.c | 20 +++----------------- > 1 file changed, 3 insertions(+), 17 deletions(-) > > Index: tip/arch/metag/kernel/irq.c > =================================================================== > --- tip.orig/arch/metag/kernel/irq.c > +++ tip/arch/metag/kernel/irq.c > @@ -261,18 +261,6 @@ int __init arch_probe_nr_irqs(void) > } > > #ifdef CONFIG_HOTPLUG_CPU > -static void route_irq(struct irq_data *data, unsigned int irq, unsigned int > cpu) > -{ > - struct irq_desc *desc = irq_to_desc(irq); > - struct irq_chip *chip = irq_data_get_irq_chip(data); > - unsigned long flags; > - > - raw_spin_lock_irqsave(&desc->lock, flags); > - if (chip->irq_set_affinity) > - chip->irq_set_affinity(data, cpumask_of(cpu), false); > - raw_spin_unlock_irqrestore(&desc->lock, flags); > -} > - > /* > * The CPU has been marked offline. Migrate IRQs off this CPU. If > * the affinity settings do not allow other CPUs, force them onto any > @@ -281,10 +269,9 @@ static void route_irq(struct irq_data *d > void migrate_irqs(void) > { > unsigned int i, cpu = smp_processor_id(); > - struct irq_desc *desc; > > - for_each_irq_desc(i, desc) { > - struct irq_data *data = irq_desc_get_irq_data(desc); > + for_each_active_irq(i) { > + struct irq_data *data = irq_get_irq_data(i); > unsigned int newcpu; > > if (irqd_is_per_cpu(data)) > @@ -303,8 +290,7 @@ void migrate_irqs(void) > newcpu = cpumask_any_and(data->affinity, > cpu_online_mask); > } > - > - route_irq(data, i, newcpu); > + irq_set_affinity(i, cpumask_of(newcpu)); > } > } > #endif /* CONFIG_HOTPLUG_CPU */ > >
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