0001-Added-new-config-option-to-enable-threaded-NAPI.patch

From 90236cdcb1783b3165a8719ba96e39e477f2ce07 Mon Sep 17 00:00:00 2001
From: Riccardo Mancini <r.mancini@santannapisa.it>
Date: Sun, 23 Jun 2019 19:36:09 +0200
Subject: [PATCH 1/4] Added new config option to enable threaded NAPI

---
 net/Kconfig    |  4 ++++
 net/core/dev.c | 37 ++++++++++++++++++++++++++++++++-----
 2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/net/Kconfig b/net/Kconfig
index d122f53c6fa2..a38033487f97 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -449,6 +449,10 @@ config FAILOVER
 	  migration of VMs with direct attached VFs by failing over to the
 	  paravirtual datapath when the VF is unplugged.
 
+config THREADED_NAPI
+	bool "Run NAPI on a dedicated kernel thread"
+	default n
+
 endif   # if NET
 
 # Used by archs to tell that they support BPF JIT compiler plus which flavour.
diff --git a/net/core/dev.c b/net/core/dev.c
index eb7fb6daa1ef..007f3e15836a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3972,12 +3972,25 @@ int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
 int dev_rx_weight __read_mostly = 64;
 int dev_tx_weight __read_mostly = 64;
 
+#ifdef CONFIG_THREADED_NAPI
+
+#else
+
+/* Called with irq disabled */
+static inline void ______napi_schedule(void)
+{
+	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
+}
+
+
+#endif
+
 /* Called with irq disabled */
 static inline void ____napi_schedule(struct softnet_data *sd,
 				     struct napi_struct *napi)
 {
 	list_add_tail(&napi->poll_list, &sd->poll_list);
-	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
+	______napi_schedule();
 }
 
 #ifdef CONFIG_RPS
@@ -4203,8 +4216,7 @@ static int rps_ipi_queued(struct softnet_data *sd)
 		sd->rps_ipi_next = mysd->rps_ipi_list;
 		mysd->rps_ipi_list = sd;
 
-		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
-		return 1;
+		______napi_schedule();
 	}
 #endif /* CONFIG_RPS */
 	return 0;
@@ -6369,12 +6381,14 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
 	return work;
 }
 
-static __latent_entropy void net_rx_action(struct softirq_action *h)
+static __latent_entropy int napi_poll_everything(void)
 {
 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
 	unsigned long time_limit = jiffies +
 		usecs_to_jiffies(netdev_budget_usecs);
 	int budget = netdev_budget;
+    	int ret = 0;
+
 	LIST_HEAD(list);
 	LIST_HEAD(repoll);
 
@@ -6411,13 +6425,26 @@ 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);
+		ret = 1;
 
 	net_rps_action_and_irq_enable(sd);
 out:
 	__kfree_skb_flush();
+	return ret;
 }
 
+#ifdef CONFIG_THREADED_NAPI
+
+#else
+
+static void net_rx_action(struct softirq_action *h)
+{
+	if (napi_poll_everything())
+		raise_softirq(NET_RX_SOFTIRQ);	
+}
+
+#endif
+
 struct netdev_adjacent {
 	struct net_device *dev;
 
-- 
2.21.0