diff options
Diffstat (limited to 'debian/patches-rt/0123-genirq-Allow-disabling-of-softirq-processing-in-irq-.patch')
| -rw-r--r-- | debian/patches-rt/0123-genirq-Allow-disabling-of-softirq-processing-in-irq-.patch | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/debian/patches-rt/0123-genirq-Allow-disabling-of-softirq-processing-in-irq-.patch b/debian/patches-rt/0123-genirq-Allow-disabling-of-softirq-processing-in-irq-.patch new file mode 100644 index 000000000..d24e2a815 --- /dev/null +++ b/debian/patches-rt/0123-genirq-Allow-disabling-of-softirq-processing-in-irq-.patch @@ -0,0 +1,144 @@ +From 70cfb822ccb0d82006eb62a4774d58021b340151 Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Tue, 31 Jan 2012 13:01:27 +0100 +Subject: [PATCH 123/347] genirq: Allow disabling of softirq processing in irq + thread context +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +The processing of softirqs in irq thread context is a performance gain +for the non-rt workloads of a system, but it's counterproductive for +interrupts which are explicitely related to the realtime +workload. Allow such interrupts to prevent softirq processing in their +thread context. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +--- + include/linux/interrupt.h | 2 ++ + include/linux/irq.h | 4 +++- + kernel/irq/manage.c | 3 +++ + kernel/irq/settings.h | 12 ++++++++++++ + kernel/softirq.c | 9 +++++++++ + 5 files changed, 29 insertions(+), 1 deletion(-) + +diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h +index cf9860d49d57..e1438fe66467 100644 +--- a/include/linux/interrupt.h ++++ b/include/linux/interrupt.h +@@ -61,6 +61,7 @@ + * 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 +@@ -74,6 +75,7 @@ + #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 9504267414a4..0f1babb9775a 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 f12f50f5b605..2bb77b0ebac8 100644 +--- a/kernel/irq/manage.c ++++ b/kernel/irq/manage.c +@@ -1533,6 +1533,9 @@ __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 e43795cd2ccf..47e2f9e23586 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 fd89f8ab85ac..3e9333d148ad 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; +-- +2.36.1 + |