@@ -347,6 +347,7 @@ struct napi_struct {
struct list_head dev_list;
struct hlist_node napi_hash_node;
unsigned int napi_id;
+ struct task_struct *thread;
};
enum {
@@ -358,6 +359,7 @@ enum {
NAPI_STATE_NO_BUSY_POLL, /* Do not add in napi_hash, no busy polling */
NAPI_STATE_IN_BUSY_POLL, /* sk_busy_loop() owns this NAPI */
NAPI_STATE_PREFER_BUSY_POLL, /* prefer busy-polling over softirq processing*/
+ NAPI_STATE_THREADED, /* The poll is performed inside its own thread*/
};
enum {
@@ -369,6 +371,7 @@ enum {
NAPIF_STATE_NO_BUSY_POLL = BIT(NAPI_STATE_NO_BUSY_POLL),
NAPIF_STATE_IN_BUSY_POLL = BIT(NAPI_STATE_IN_BUSY_POLL),
NAPIF_STATE_PREFER_BUSY_POLL = BIT(NAPI_STATE_PREFER_BUSY_POLL),
+ NAPIF_STATE_THREADED = BIT(NAPI_STATE_THREADED),
};
enum gro_result {
@@ -495,6 +498,8 @@ static inline bool napi_complete(struct napi_struct *n)
return napi_complete_done(n, 0);
}
+int napi_set_threaded(struct napi_struct *n, bool threaded);
+
/**
* napi_disable - prevent NAPI from scheduling
* @n: NAPI context
@@ -91,6 +91,7 @@
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/skbuff.h>
+#include <linux/kthread.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <net/net_namespace.h>
@@ -1475,6 +1476,36 @@ void netdev_notify_peers(struct net_device *dev)
}
EXPORT_SYMBOL(netdev_notify_peers);
+static int napi_threaded_poll(void *data);
+
+static int napi_kthread_create(struct napi_struct *n)
+{
+ int err = 0;
+
+ /* Create and wake up the kthread once to put it in
+ * TASK_INTERRUPTIBLE mode to avoid the blocked task
+ * warning and work with loadavg.
+ */
+ n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
+ n->dev->name, n->napi_id);
+ if (IS_ERR(n->thread)) {
+ err = PTR_ERR(n->thread);
+ pr_err("kthread_run failed with err %d\n", err);
+ n->thread = NULL;
+ }
+
+ return err;
+}
+
+static void napi_kthread_stop(struct napi_struct *n)
+{
+ if (!n->thread)
+ return;
+ kthread_stop(n->thread);
+ clear_bit(NAPI_STATE_THREADED, &n->state);
+ n->thread = NULL;
+}
+
static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
{
const struct net_device_ops *ops = dev->netdev_ops;
@@ -4234,6 +4265,11 @@ int gro_normal_batch __read_mostly = 8;
static inline void ____napi_schedule(struct softnet_data *sd,
struct napi_struct *napi)
{
+ if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
+ wake_up_process(napi->thread);
+ return;
+ }
+
list_add_tail(&napi->poll_list, &sd->poll_list);
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
}
@@ -6690,6 +6726,29 @@ static void init_gro_hash(struct napi_struct *napi)
napi->gro_bitmask = 0;
}
+int napi_set_threaded(struct napi_struct *n, bool threaded)
+{
+ int err = 0;
+
+ ASSERT_RTNL();
+
+ if (threaded == !!test_bit(NAPI_STATE_THREADED, &n->state))
+ return 0;
+ if (threaded) {
+ if (!n->thread) {
+ err = napi_kthread_create(n);
+ if (err)
+ goto out;
+ }
+ set_bit(NAPI_STATE_THREADED, &n->state);
+ } else {
+ clear_bit(NAPI_STATE_THREADED, &n->state);
+ }
+
+out:
+ return err;
+}
+
void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
int (*poll)(struct napi_struct *, int), int weight)
{
@@ -6731,6 +6790,7 @@ void napi_disable(struct napi_struct *n)
msleep(1);
hrtimer_cancel(&n->timer);
+ napi_kthread_stop(n);
clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &n->state);
clear_bit(NAPI_STATE_DISABLE, &n->state);
@@ -6859,6 +6919,51 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
return work;
}
+static int napi_thread_wait(struct napi_struct *napi)
+{
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ while (!kthread_should_stop() && !napi_disable_pending(napi)) {
+ if (test_bit(NAPI_STATE_SCHED, &napi->state)) {
+ WARN_ON(!list_empty(&napi->poll_list));
+ __set_current_state(TASK_RUNNING);
+ return 0;
+ }
+
+ schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+ __set_current_state(TASK_RUNNING);
+ return -1;
+}
+
+static int napi_threaded_poll(void *data)
+{
+ struct napi_struct *napi = data;
+ void *have;
+
+ while (!napi_thread_wait(napi)) {
+ for (;;) {
+ bool repoll = false;
+
+ local_bh_disable();
+
+ have = netpoll_poll_lock(napi);
+ __napi_poll(napi, &repoll);
+ netpoll_poll_unlock(have);
+
+ __kfree_skb_flush();
+ local_bh_enable();
+
+ if (!repoll)
+ break;
+
+ cond_resched();
+ }
+ }
+ return 0;
+}
+
static __latent_entropy void net_rx_action(struct softirq_action *h)
{
struct softnet_data *sd = this_cpu_ptr(&softnet_data);