diff options
Diffstat (limited to 'kernel/irq/cpuhotplug.c')
| -rw-r--r-- | kernel/irq/cpuhotplug.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index 011f8c4c63da..4684b7595e63 100644 --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -11,6 +11,7 @@ #include <linux/interrupt.h> #include <linux/ratelimit.h> #include <linux/irq.h> +#include <linux/cpumask.h> #include "internals.h" @@ -20,6 +21,7 @@ static bool migrate_one_irq(struct irq_desc *desc) const struct cpumask *affinity = d->common->affinity; struct irq_chip *c; bool ret = false; + struct cpumask available_cpus; /* * If this is a per-CPU interrupt, or the affinity does not @@ -29,8 +31,37 @@ static bool migrate_one_irq(struct irq_desc *desc) !cpumask_test_cpu(smp_processor_id(), affinity)) return false; + cpumask_copy(&available_cpus, affinity); + cpumask_andnot(&available_cpus, &available_cpus, cpu_isolated_mask); + affinity = &available_cpus; + if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { - affinity = cpu_online_mask; + /* + * The order of preference for selecting a fallback CPU is + * + * (1) online and un-isolated CPU from default affinity + * (2) online and un-isolated CPU + * (3) online CPU + */ + cpumask_andnot(&available_cpus, cpu_online_mask, + cpu_isolated_mask); + if (cpumask_intersects(&available_cpus, irq_default_affinity)) + cpumask_and(&available_cpus, &available_cpus, + irq_default_affinity); + else if (cpumask_empty(&available_cpus)) + affinity = cpu_online_mask; + + /* + * We are overriding the affinity with all online and + * un-isolated cpus. irq_set_affinity_locked() call + * below notify this mask to PM QOS affinity listener. + * That results in applying the CPU_DMA_LATENCY QOS + * to all the CPUs specified in the mask. But the low + * level irqchip driver sets the affinity of an irq + * to only one CPU. So pick only one CPU from the + * prepared mask while overriding the user affinity. + */ + affinity = cpumask_of(cpumask_any(affinity)); ret = true; } @@ -38,7 +69,7 @@ static bool migrate_one_irq(struct irq_desc *desc) if (!c->irq_set_affinity) { pr_debug("IRQ%u: unable to set affinity\n", d->irq); } else { - int r = irq_do_set_affinity(d, affinity, false); + int r = irq_set_affinity_locked(d, affinity, false); if (r) pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n", d->irq, r); @@ -69,6 +100,9 @@ void irq_migrate_all_off_this_cpu(void) bool affinity_broken; desc = irq_to_desc(irq); + if (!desc) + continue; + raw_spin_lock(&desc->lock); affinity_broken = migrate_one_irq(desc); raw_spin_unlock(&desc->lock); |