@@ -465,6 +465,14 @@ extern void thread_do_softirq(void);
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
extern void __raise_softirq_irqoff(unsigned int nr);
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void __raise_softirq_irqoff_ksoft(unsigned int nr);
+#else
+static inline void __raise_softirq_irqoff_ksoft(unsigned int nr)
+{
+ __raise_softirq_irqoff(nr);
+}
+#endif
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
@@ -641,6 +641,19 @@ void __raise_softirq_irqoff(unsigned int nr)
}
/*
+ * Same as __raise_softirq_irqoff() but will process them in ksoftirqd
+ */
+void __raise_softirq_irqoff_ksoft(unsigned int nr)
+{
+ if (WARN_ON_ONCE(!__this_cpu_read(ksoftirqd)))
+ return;
+ trace_softirq_raise(nr);
+ or_softirq_pending(1UL << nr);
+ __this_cpu_read(ksoftirqd)->softirqs_raised |= (1U << nr);
+ wakeup_softirqd();
+}
+
+/*
* This function must run with irqs disabled!
*/
void raise_softirq_irqoff(unsigned int nr)
@@ -4955,7 +4955,7 @@ static void net_rx_action(struct softirq_action *h)
list_splice_tail(&repoll, &list);
list_splice(&list, &sd->poll_list);
if (!list_empty(&sd->poll_list))
- __raise_softirq_irqoff(NET_RX_SOFTIRQ);
+ __raise_softirq_irqoff_ksoft(NET_RX_SOFTIRQ);
net_rps_action_and_irq_enable(sd);
}
If the NET_RX uses up all of his budget it moves the following NAPI invocations into the `ksoftirqd`. On -RT it does not do so. Instead it rises the NET_RX softirq in its current context again. In order to get closer to mainline's behaviour this patch provides __raise_softirq_irqoff_ksoft() which raises the softirq in the ksoftird. Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- include/linux/interrupt.h | 8 ++++++++ kernel/softirq.c | 13 +++++++++++++ net/core/dev.c | 2 +- 3 files changed, 22 insertions(+), 1 deletion(-)