diff options
Diffstat (limited to 'kernel/irq_work.c')
-rw-r--r-- | kernel/irq_work.c | 56 |
1 files changed, 43 insertions, 13 deletions
diff --git a/kernel/irq_work.c b/kernel/irq_work.c index bcf107ce0854..2899ba0d23d1 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -17,6 +17,7 @@ #include <linux/cpu.h> #include <linux/notifier.h> #include <linux/smp.h> +#include <linux/interrupt.h> #include <asm/processor.h> @@ -65,6 +66,8 @@ void __weak arch_irq_work_raise(void) */ bool irq_work_queue_on(struct irq_work *work, int cpu) { + struct llist_head *list; + /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(cpu)); @@ -75,7 +78,12 @@ bool irq_work_queue_on(struct irq_work *work, int cpu) if (!irq_work_claim(work)) return false; - if (llist_add(&work->llnode, &per_cpu(raised_list, cpu))) + if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL) && !(work->flags & IRQ_WORK_HARD_IRQ)) + list = &per_cpu(lazy_list, cpu); + else + list = &per_cpu(raised_list, cpu); + + if (llist_add(&work->llnode, list)) arch_send_call_function_single_ipi(cpu); return true; @@ -86,6 +94,9 @@ EXPORT_SYMBOL_GPL(irq_work_queue_on); /* Enqueue the irq work @work on the current CPU */ bool irq_work_queue(struct irq_work *work) { + struct llist_head *list; + bool lazy_work, realtime = IS_ENABLED(CONFIG_PREEMPT_RT_FULL); + /* Only queue if not already pending */ if (!irq_work_claim(work)) return false; @@ -93,13 +104,15 @@ bool irq_work_queue(struct irq_work *work) /* Queue the entry and raise the IPI if needed. */ preempt_disable(); - /* If the work is "lazy", handle it from next tick if any */ - if (work->flags & IRQ_WORK_LAZY) { - if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) && - tick_nohz_tick_stopped()) - arch_irq_work_raise(); - } else { - if (llist_add(&work->llnode, this_cpu_ptr(&raised_list))) + lazy_work = work->flags & IRQ_WORK_LAZY; + + if (lazy_work || (realtime && !(work->flags & IRQ_WORK_HARD_IRQ))) + list = this_cpu_ptr(&lazy_list); + else + list = this_cpu_ptr(&raised_list); + + if (llist_add(&work->llnode, list)) { + if (!lazy_work || tick_nohz_tick_stopped()) arch_irq_work_raise(); } @@ -116,9 +129,8 @@ bool irq_work_needs_cpu(void) raised = this_cpu_ptr(&raised_list); lazy = this_cpu_ptr(&lazy_list); - if (llist_empty(raised) || arch_irq_work_has_interrupt()) - if (llist_empty(lazy)) - return false; + if (llist_empty(raised) && llist_empty(lazy)) + return false; /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); @@ -132,7 +144,7 @@ static void irq_work_run_list(struct llist_head *list) struct irq_work *work; struct llist_node *llnode; - BUG_ON(!irqs_disabled()); + BUG_ON_NONRT(!irqs_disabled()); if (llist_empty(list)) return; @@ -169,7 +181,16 @@ static void irq_work_run_list(struct llist_head *list) void irq_work_run(void) { irq_work_run_list(this_cpu_ptr(&raised_list)); - irq_work_run_list(this_cpu_ptr(&lazy_list)); + if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) { + /* + * NOTE: we raise softirq via IPI for safety, + * and execute in irq_work_tick() to move the + * overhead from hard to soft irq context. + */ + if (!llist_empty(this_cpu_ptr(&lazy_list))) + raise_softirq(TIMER_SOFTIRQ); + } else + irq_work_run_list(this_cpu_ptr(&lazy_list)); } EXPORT_SYMBOL_GPL(irq_work_run); @@ -179,8 +200,17 @@ void irq_work_tick(void) if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) irq_work_run_list(raised); + + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) + irq_work_run_list(this_cpu_ptr(&lazy_list)); +} + +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) +void irq_work_tick_soft(void) +{ irq_work_run_list(this_cpu_ptr(&lazy_list)); } +#endif /* * Synchronize against the irq_work @entry, ensures the entry is not |