diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 9fbabce90dc3594270dcb0d87290c5523717c42b..aed4f168bfd5f0c34facb967cc0e7b5635fb9234 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -62,6 +62,7 @@ * interrupt handler after suspending interrupts. For system * wakeup devices users need to implement wakeup detection in * their interrupt handlers. + * IRQF_NO_SOFTIRQ_CALL - Do not process softirqs in the irq thread context (RT) */ #define IRQF_SHARED 0x00000080 #define IRQF_PROBE_SHARED 0x00000100 @@ -75,6 +76,7 @@ #define IRQF_NO_THREAD 0x00010000 #define IRQF_EARLY_RESUME 0x00020000 #define IRQF_COND_SUSPEND 0x00040000 +#define IRQF_NO_SOFTIRQ_CALL 0x00080000 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) diff --git a/include/linux/irq.h b/include/linux/irq.h index ca367d98a991e386ae42b5a70677f95c7ed5ee1f..6734ef85700366f676b7395c1aa66140716694db 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -69,6 +69,7 @@ enum irqchip_irq_state; * IRQ_IS_POLLED - Always polled by another interrupt. Exclude * it from the spurious interrupt detection * mechanism and from core side polling. + * IRQ_NO_SOFTIRQ_CALL - No softirq processing in the irq thread context (RT) * IRQ_DISABLE_UNLAZY - Disable lazy irq disable */ enum { @@ -96,13 +97,14 @@ enum { IRQ_PER_CPU_DEVID = (1 << 17), IRQ_IS_POLLED = (1 << 18), IRQ_DISABLE_UNLAZY = (1 << 19), + IRQ_NO_SOFTIRQ_CALL = (1 << 20), }; #define IRQF_MODIFY_MASK \ (IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \ IRQ_NOAUTOEN | IRQ_MOVE_PCNTXT | IRQ_LEVEL | IRQ_NO_BALANCING | \ IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID | \ - IRQ_IS_POLLED | IRQ_DISABLE_UNLAZY) + IRQ_IS_POLLED | IRQ_DISABLE_UNLAZY | IRQ_NO_SOFTIRQ_CALL) #define IRQ_NO_BALANCING_MASK (IRQ_PER_CPU | IRQ_NO_BALANCING) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 1051f9c29492e4d09957ad8d3e29c9ad00552f19..9acc2dd43bb4ea4bd8827dc4bc5b21bae860c7d1 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1078,7 +1078,15 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) atomic_inc(&desc->threads_handled); irq_finalize_oneshot(desc, action); - local_bh_enable(); + /* + * Interrupts which have real time requirements can be set up + * to avoid softirq processing in the thread handler. This is + * safe as these interrupts do not raise soft interrupts. + */ + if (irq_settings_no_softirq_call(desc)) + _local_bh_enable(); + else + local_bh_enable(); return ret; } @@ -1629,6 +1637,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) irqd_set(&desc->irq_data, IRQD_NO_BALANCING); } + if (new->flags & IRQF_NO_SOFTIRQ_CALL) + irq_settings_set_no_softirq_call(desc); + if (irq_settings_can_autoenable(desc)) { irq_startup(desc, IRQ_RESEND, IRQ_START_COND); } else { diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h index e43795cd2ccfba2f848dcaa0f3b37aff562af83b..47e2f9e23586fc7f239be2e5bd8d1d0350fdfd8d 100644 --- a/kernel/irq/settings.h +++ b/kernel/irq/settings.h @@ -17,6 +17,7 @@ enum { _IRQ_PER_CPU_DEVID = IRQ_PER_CPU_DEVID, _IRQ_IS_POLLED = IRQ_IS_POLLED, _IRQ_DISABLE_UNLAZY = IRQ_DISABLE_UNLAZY, + _IRQ_NO_SOFTIRQ_CALL = IRQ_NO_SOFTIRQ_CALL, _IRQF_MODIFY_MASK = IRQF_MODIFY_MASK, }; @@ -31,6 +32,7 @@ enum { #define IRQ_PER_CPU_DEVID GOT_YOU_MORON #define IRQ_IS_POLLED GOT_YOU_MORON #define IRQ_DISABLE_UNLAZY GOT_YOU_MORON +#define IRQ_NO_SOFTIRQ_CALL GOT_YOU_MORON #undef IRQF_MODIFY_MASK #define IRQF_MODIFY_MASK GOT_YOU_MORON @@ -41,6 +43,16 @@ irq_settings_clr_and_set(struct irq_desc *desc, u32 clr, u32 set) desc->status_use_accessors |= (set & _IRQF_MODIFY_MASK); } +static inline bool irq_settings_no_softirq_call(struct irq_desc *desc) +{ + return desc->status_use_accessors & _IRQ_NO_SOFTIRQ_CALL; +} + +static inline void irq_settings_set_no_softirq_call(struct irq_desc *desc) +{ + desc->status_use_accessors |= _IRQ_NO_SOFTIRQ_CALL; +} + static inline bool irq_settings_is_per_cpu(struct irq_desc *desc) { return desc->status_use_accessors & _IRQ_PER_CPU; diff --git a/kernel/softirq.c b/kernel/softirq.c index fd89f8ab85ac780c03f998e1312c832e201219f4..3e9333d148adb6d83556e8988c133c6958caaac3 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -598,6 +598,15 @@ void __local_bh_enable(void) } EXPORT_SYMBOL(__local_bh_enable); +void _local_bh_enable(void) +{ + if (WARN_ON(current->softirq_nestcnt == 0)) + return; + if (--current->softirq_nestcnt == 0) + migrate_enable(); +} +EXPORT_SYMBOL(_local_bh_enable); + int in_serving_softirq(void) { return current->flags & PF_IN_SOFTIRQ; diff --git a/net/core/dev.c b/net/core/dev.c index 4a16d6adf2c9a92d9b3fab85cd2405ddc47a7f34..1a065b881265381243d3630aabe9a521e20e4558 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4559,11 +4559,9 @@ int netif_rx_ni(struct sk_buff *skb) trace_netif_rx_ni_entry(skb); - preempt_disable(); + local_bh_disable(); err = netif_rx_internal(skb); - if (local_softirq_pending()) - do_softirq(); - preempt_enable(); + local_bh_enable(); return err; }