| Message ID | 1442467166-1460-3-git-send-email-yangyingliang@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17/09/15 06:19, Yang Yingliang wrote: > Add move_irqs() into kernel/irq/migration.c. > So we can use it to migrate interrupts, when > cpu is offline. > > 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> > --- > include/linux/irq.h | 4 +++ > kernel/irq/migration.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 70 insertions(+) > > diff --git a/include/linux/irq.h b/include/linux/irq.h > index 6f8b340..64e3a02 100644 > --- a/include/linux/irq.h > +++ b/include/linux/irq.h > @@ -446,6 +446,10 @@ static inline void irq_move_irq(struct irq_data *data) { } > static inline void irq_move_masked_irq(struct irq_data *data) { } > #endif > > +#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_IRQ_MIGRATION) && defined(CONFIG_HOTPLUG_CPU) > +void move_irqs(void); > +#endif > + I don't think having this prototype guarded by this #if is very useful. You can probably leave it standalone. Thanks, M.
On Thu, 17 Sep 2015, Marc Zyngier wrote: > On 17/09/15 06:19, Yang Yingliang wrote: > > Add move_irqs() into kernel/irq/migration.c. > > So we can use it to migrate interrupts, when > > cpu is offline. > > > > 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> > > --- > > include/linux/irq.h | 4 +++ > > kernel/irq/migration.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 70 insertions(+) > > > > diff --git a/include/linux/irq.h b/include/linux/irq.h > > index 6f8b340..64e3a02 100644 > > --- a/include/linux/irq.h > > +++ b/include/linux/irq.h > > @@ -446,6 +446,10 @@ static inline void irq_move_irq(struct irq_data *data) { } > > static inline void irq_move_masked_irq(struct irq_data *data) { } > > #endif > > > > +#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_IRQ_MIGRATION) && defined(CONFIG_HOTPLUG_CPU) > > +void move_irqs(void); > > +#endif > > + > > I don't think having this prototype guarded by this #if is very useful. > You can probably leave it standalone. Yes, there is no point if the function name is unique. Though move_irqs() is rather undescriptive. irq_break_affinities() might describe it quite well, but feel free to come up with soemthing better. Thanks, tglx
On Fri, Sep 18, 2015 at 12:04:06AM +0200, Thomas Gleixner wrote: > On Thu, 17 Sep 2015, Marc Zyngier wrote: > > I don't think having this prototype guarded by this #if is very useful. > > You can probably leave it standalone. > > Yes, there is no point if the function name is unique. Though > move_irqs() is rather undescriptive. irq_break_affinities() might > describe it quite well, but feel free to come up with soemthing better. I don't think "irq_break_affinities" is anywhere near a good name - it's not about always breaking affinities (moving an IRQ off one CPU onto another within the current affinity setting does not break the affinity.) irq_migrate_all() irq_migrate_all_off_this_cpu() irq_this_cpu_hotunplug() irq_cpu_hotunplug()
On 2015/9/18 6:09, Russell King - ARM Linux wrote: > On Fri, Sep 18, 2015 at 12:04:06AM +0200, Thomas Gleixner wrote: >> On Thu, 17 Sep 2015, Marc Zyngier wrote: >>> I don't think having this prototype guarded by this #if is very useful. >>> You can probably leave it standalone. >> >> Yes, there is no point if the function name is unique. Though >> move_irqs() is rather undescriptive. irq_break_affinities() might >> describe it quite well, but feel free to come up with soemthing better. > > I don't think "irq_break_affinities" is anywhere near a good name - it's > not about always breaking affinities (moving an IRQ off one CPU onto > another within the current affinity setting does not break the affinity.) > > irq_migrate_all() > > irq_migrate_all_off_this_cpu() > > irq_this_cpu_hotunplug() > > irq_cpu_hotunplug() > irq_migrate_all_off_this_cpu() describe it well, I will choose it. Thanks, Yang
diff --git a/include/linux/irq.h b/include/linux/irq.h index 6f8b340..64e3a02 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -446,6 +446,10 @@ static inline void irq_move_irq(struct irq_data *data) { } static inline void irq_move_masked_irq(struct irq_data *data) { } #endif +#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_IRQ_MIGRATION) && defined(CONFIG_HOTPLUG_CPU) +void move_irqs(void); +#endif + extern int no_irq_affinity; #ifdef CONFIG_HARDIRQS_SW_RESEND diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c index 1ff2b77..75bff60 100644 --- a/kernel/irq/migration.c +++ b/kernel/irq/migration.c @@ -1,6 +1,7 @@ #include <linux/irq.h> #include <linux/interrupt.h> +#include <linux/ratelimit.h> #include "internals.h" @@ -79,3 +80,68 @@ void irq_move_irq(struct irq_data *idata) idata->chip->irq_unmask(idata); } #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 = d->affinity; + 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_warn_ratelimited("IRQ%u: unable to set affinity\n", d->irq); + } else { + int r = irq_do_set_affinity(d, affinity, false); + if (r) + pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n", d->irq, r); + } + + 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 move_irqs(void) +{ + unsigned int irq; + struct irq_desc *desc; + unsigned long flags; + + local_irq_save(flags); + + for_each_active_irq(irq) { + bool affinity_broken; + + desc = irq_to_desc(irq); + 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", + irq, smp_processor_id()); + } + + local_irq_restore(flags); +} +#endif /* CONFIG_HOTPLUG_CPU */
Add move_irqs() into kernel/irq/migration.c. So we can use it to migrate interrupts, when cpu is offline. 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> --- include/linux/irq.h | 4 +++ kernel/irq/migration.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+)