diff options
Diffstat (limited to 'debian/patches-rt/0199-net-provide-a-way-to-delegate-processing-a-softirq-t.patch')
| -rw-r--r-- | debian/patches-rt/0199-net-provide-a-way-to-delegate-processing-a-softirq-t.patch | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/debian/patches-rt/0199-net-provide-a-way-to-delegate-processing-a-softirq-t.patch b/debian/patches-rt/0199-net-provide-a-way-to-delegate-processing-a-softirq-t.patch new file mode 100644 index 000000000..ad68c8b6d --- /dev/null +++ b/debian/patches-rt/0199-net-provide-a-way-to-delegate-processing-a-softirq-t.patch @@ -0,0 +1,89 @@ +From e035c89c203c5d80fa945338da5efe3ec563c7f7 Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Wed, 20 Jan 2016 15:39:05 +0100 +Subject: [PATCH 199/347] net: provide a way to delegate processing a softirq + to ksoftirqd +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +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 | 21 +++++++++++++++++++++ + net/core/dev.c | 2 +- + 3 files changed, 30 insertions(+), 1 deletion(-) + +diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h +index e1438fe66467..97d9ba26915e 100644 +--- a/include/linux/interrupt.h ++++ b/include/linux/interrupt.h +@@ -518,6 +518,14 @@ 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); +diff --git a/kernel/softirq.c b/kernel/softirq.c +index 27a4bb2303d0..25bcf2f2714b 100644 +--- a/kernel/softirq.c ++++ b/kernel/softirq.c +@@ -721,6 +721,27 @@ void __raise_softirq_irqoff(unsigned int nr) + wakeup_proper_softirq(nr); + } + ++/* ++ * Same as __raise_softirq_irqoff() but will process them in ksoftirqd ++ */ ++void __raise_softirq_irqoff_ksoft(unsigned int nr) ++{ ++ unsigned int mask; ++ ++ if (WARN_ON_ONCE(!__this_cpu_read(ksoftirqd) || ++ !__this_cpu_read(ktimer_softirqd))) ++ return; ++ mask = 1UL << nr; ++ ++ trace_softirq_raise(nr); ++ or_softirq_pending(mask); ++ if (mask & TIMER_SOFTIRQS) ++ __this_cpu_read(ktimer_softirqd)->softirqs_raised |= mask; ++ else ++ __this_cpu_read(ksoftirqd)->softirqs_raised |= mask; ++ wakeup_proper_softirq(nr); ++} ++ + /* + * This function must run with irqs disabled! + */ +diff --git a/net/core/dev.c b/net/core/dev.c +index a59b1db02f8b..2bf357d5602b 100644 +--- a/net/core/dev.c ++++ b/net/core/dev.c +@@ -6391,7 +6391,7 @@ static __latent_entropy 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); + out: +-- +2.36.1 + |