diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 | ||||
| -rw-r--r-- | include/linux/interrupt.h | 47 | ||||
| -rw-r--r-- | include/linux/irqnr.h | 36 |
3 files changed, 69 insertions, 15 deletions
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index f1d151c03164..a04b73c40173 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -147,6 +147,7 @@ enum cpuhp_state { CPUHP_AP_IRQ_EIOINTC_STARTING, CPUHP_AP_IRQ_AVECINTC_STARTING, CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING, + CPUHP_AP_IRQ_THEAD_ACLINT_SSWI_STARTING, CPUHP_AP_IRQ_RISCV_IMSIC_STARTING, CPUHP_AP_IRQ_RISCV_SBI_IPI_STARTING, CPUHP_AP_ARM_MVEBU_COHERENCY, diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 457151f9f263..8cd9327e4e78 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -616,6 +616,53 @@ extern void __raise_softirq_irqoff(unsigned int nr); extern void raise_softirq_irqoff(unsigned int nr); extern void raise_softirq(unsigned int nr); +/* + * With forced-threaded interrupts enabled a raised softirq is deferred to + * ksoftirqd unless it can be handled within the threaded interrupt. This + * affects timer_list timers and hrtimers which are explicitly marked with + * HRTIMER_MODE_SOFT. + * With PREEMPT_RT enabled more hrtimers are moved to softirq for processing + * which includes all timers which are not explicitly marked HRTIMER_MODE_HARD. + * Userspace controlled timers (like the clock_nanosleep() interface) is divided + * into two categories: Tasks with elevated scheduling policy including + * SCHED_{FIFO|RR|DL} and the remaining scheduling policy. The tasks with the + * elevated scheduling policy are woken up directly from the HARDIRQ while all + * other wake ups are delayed to softirq and so to ksoftirqd. + * + * The ksoftirqd runs at SCHED_OTHER policy at which it should remain since it + * handles the softirq in an overloaded situation (not handled everything + * within its last run). + * If the timers are handled at SCHED_OTHER priority then they competes with all + * other SCHED_OTHER tasks for CPU resources are possibly delayed. + * Moving timers softirqs to a low priority SCHED_FIFO thread instead ensures + * that timer are performed before scheduling any SCHED_OTHER thread. + */ +DECLARE_PER_CPU(struct task_struct *, ktimerd); +DECLARE_PER_CPU(unsigned long, pending_timer_softirq); +void raise_ktimers_thread(unsigned int nr); + +static inline unsigned int local_timers_pending_force_th(void) +{ + return __this_cpu_read(pending_timer_softirq); +} + +static inline void raise_timer_softirq(unsigned int nr) +{ + lockdep_assert_in_irq(); + if (force_irqthreads()) + raise_ktimers_thread(nr); + else + __raise_softirq_irqoff(nr); +} + +static inline unsigned int local_timers_pending(void) +{ + if (force_irqthreads()) + return local_timers_pending_force_th(); + else + return local_softirq_pending(); +} + DECLARE_PER_CPU(struct task_struct *, ksoftirqd); static inline struct task_struct *this_cpu_ksoftirqd(void) diff --git a/include/linux/irqnr.h b/include/linux/irqnr.h index 3496baa0b07f..e97206c721a0 100644 --- a/include/linux/irqnr.h +++ b/include/linux/irqnr.h @@ -5,30 +5,36 @@ #include <uapi/linux/irqnr.h> -extern int nr_irqs; +unsigned int irq_get_nr_irqs(void) __pure; +unsigned int irq_set_nr_irqs(unsigned int nr); extern struct irq_desc *irq_to_desc(unsigned int irq); unsigned int irq_get_next_irq(unsigned int offset); -# define for_each_irq_desc(irq, desc) \ - for (irq = 0, desc = irq_to_desc(irq); irq < nr_irqs; \ - irq++, desc = irq_to_desc(irq)) \ - if (!desc) \ - ; \ - else - +#define for_each_irq_desc(irq, desc) \ + for (unsigned int __nr_irqs__ = irq_get_nr_irqs(); __nr_irqs__; \ + __nr_irqs__ = 0) \ + for (irq = 0, desc = irq_to_desc(irq); irq < __nr_irqs__; \ + irq++, desc = irq_to_desc(irq)) \ + if (!desc) \ + ; \ + else # define for_each_irq_desc_reverse(irq, desc) \ - for (irq = nr_irqs - 1, desc = irq_to_desc(irq); irq >= 0; \ - irq--, desc = irq_to_desc(irq)) \ + for (irq = irq_get_nr_irqs() - 1, desc = irq_to_desc(irq); \ + irq >= 0; irq--, desc = irq_to_desc(irq)) \ if (!desc) \ ; \ else -# define for_each_active_irq(irq) \ - for (irq = irq_get_next_irq(0); irq < nr_irqs; \ - irq = irq_get_next_irq(irq + 1)) +#define for_each_active_irq(irq) \ + for (unsigned int __nr_irqs__ = irq_get_nr_irqs(); __nr_irqs__; \ + __nr_irqs__ = 0) \ + for (irq = irq_get_next_irq(0); irq < __nr_irqs__; \ + irq = irq_get_next_irq(irq + 1)) -#define for_each_irq_nr(irq) \ - for (irq = 0; irq < nr_irqs; irq++) +#define for_each_irq_nr(irq) \ + for (unsigned int __nr_irqs__ = irq_get_nr_irqs(); __nr_irqs__; \ + __nr_irqs__ = 0) \ + for (irq = 0; irq < __nr_irqs__; irq++) #endif |