diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index addfcc74d851716cc2ddf39d26fb250ccc113652..4fe7af8a49078a83bdf253d4c9e821256c602a25 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -2,6 +2,7 @@
#define IO_URING_TYPES_H
#include <linux/blkdev.h>
+#include <linux/hashtable.h>
#include <linux/task_work.h>
#include <linux/bitmap.h>
#include <linux/llist.h>
@@ -247,6 +248,7 @@ struct io_ring_ctx {
struct percpu_ref refs;
enum task_work_notify_mode notify_method;
+ unsigned sq_thread_idle;
} ____cacheline_aligned_in_smp;
/* submission data */
@@ -410,7 +412,18 @@ struct io_ring_ctx {
struct callback_head poll_wq_task_work;
struct list_head defer_list;
- unsigned sq_thread_idle;
+
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ struct list_head napi_list; /* track busy poll napi_id */
+ spinlock_t napi_lock; /* napi_list lock */
+
+ /* napi busy poll default timeout */
+ unsigned int napi_busy_poll_to;
+ bool napi_prefer_busy_poll;
+
+ DECLARE_HASHTABLE(napi_ht, 4);
+#endif
+
/* protected by ->completion_lock */
unsigned evfd_last_cq_tail;
diff --git a/io_uring/Makefile b/io_uring/Makefile
index 42afe4a1ff3182a580b7827b9be974dba62fa916..2e1d4e03799c34f4e56fa2cc5397eaeb69756498 100644
--- a/io_uring/Makefile
+++ b/io_uring/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_IO_URING) += io_uring.o xattr.o nop.o fs.o splice.o \
notif.o waitid.o register.o truncate.o
obj-$(CONFIG_IO_WQ) += io-wq.o
obj-$(CONFIG_FUTEX) += futex.o
+obj-$(CONFIG_NET_RX_BUSY_POLL) += napi.o
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 5311f19faa4c3b97e8f24f1abe989fc6d2740ffe..479f610e314f56500496749135999dcd798a56d9 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -95,6 +95,7 @@
#include "notif.h"
#include "waitid.h"
#include "futex.h"
+#include "napi.h"
#include "timeout.h"
#include "poll.h"
@@ -349,6 +350,8 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
INIT_WQ_LIST(&ctx->submit_state.compl_reqs);
INIT_HLIST_HEAD(&ctx->cancelable_uring_cmd);
+ io_napi_init(ctx);
+
return ctx;
err:
kfree(ctx->cancel_table.hbs);
@@ -2602,9 +2605,13 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
if (get_timespec64(&ts, uts))
return -EFAULT;
+
iowq.timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
+ io_napi_adjust_timeout(ctx, &iowq, &ts);
}
+ io_napi_busy_loop(ctx, &iowq);
+
trace_io_uring_cqring_wait(ctx, min_events);
do {
int nr_wait = (int) iowq.cq_tail - READ_ONCE(ctx->rings->cq.tail);
@@ -2897,6 +2904,7 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
io_req_caches_free(ctx);
if (ctx->hash_map)
io_wq_put_hash(ctx->hash_map);
+ io_napi_free(ctx);
kfree(ctx->cancel_table.hbs);
kfree(ctx->cancel_table_locked.hbs);
kfree(ctx->io_bl);
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 859f6e0580e37263e97fd47013c9e182d88597e1..1ca99522811b40ddb9050add2087eb374aea9805 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -42,6 +42,10 @@ struct io_wait_queue {
unsigned nr_timeouts;
ktime_t timeout;
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ unsigned int napi_busy_poll_to;
+ bool napi_prefer_busy_poll;
+#endif
};
static inline bool io_should_wake(struct io_wait_queue *iowq)
diff --git a/io_uring/napi.c b/io_uring/napi.c
new file mode 100644
index 0000000000000000000000000000000000000000..1112cc39153cb5c7a90f2f043bfab4ef25f8318a
--- /dev/null
+++ b/io_uring/napi.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "io_uring.h"
+#include "napi.h"
+
+#ifdef CONFIG_NET_RX_BUSY_POLL
+
+/* Timeout for cleanout of stale entries. */
+#define NAPI_TIMEOUT (60 * SEC_CONVERSION)
+
+struct io_napi_entry {
+ unsigned int napi_id;
+ struct list_head list;
+
+ unsigned long timeout;
+ struct hlist_node node;
+
+ struct rcu_head rcu;
+};
+
+static struct io_napi_entry *io_napi_hash_find(struct hlist_head *hash_list,
+ unsigned int napi_id)
+{
+ struct io_napi_entry *e;
+
+ hlist_for_each_entry_rcu(e, hash_list, node) {
+ if (e->napi_id != napi_id)
+ continue;
+ e->timeout = jiffies + NAPI_TIMEOUT;
+ return e;
+ }
+
+ return NULL;
+}
+
+void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock)
+{
+ struct hlist_head *hash_list;
+ unsigned int napi_id;
+ struct sock *sk;
+ struct io_napi_entry *e;
+
+ sk = sock->sk;
+ if (!sk)
+ return;
+
+ napi_id = READ_ONCE(sk->sk_napi_id);
+
+ /* Non-NAPI IDs can be rejected. */
+ if (napi_id < MIN_NAPI_ID)
+ return;
+
+ hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))];
+
+ rcu_read_lock();
+ e = io_napi_hash_find(hash_list, napi_id);
+ if (e) {
+ e->timeout = jiffies + NAPI_TIMEOUT;
+ rcu_read_unlock();
+ return;
+ }
+ rcu_read_unlock();
+
+ e = kmalloc(sizeof(*e), GFP_NOWAIT);
+ if (!e)
+ return;
+
+ e->napi_id = napi_id;
+ e->timeout = jiffies + NAPI_TIMEOUT;
+
+ spin_lock(&ctx->napi_lock);
+ if (unlikely(io_napi_hash_find(hash_list, napi_id))) {
+ spin_unlock(&ctx->napi_lock);
+ kfree(e);
+ return;
+ }
+
+ hlist_add_tail_rcu(&e->node, hash_list);
+ list_add_tail(&e->list, &ctx->napi_list);
+ spin_unlock(&ctx->napi_lock);
+}
+
+static void __io_napi_remove_stale(struct io_ring_ctx *ctx)
+{
+ struct io_napi_entry *e;
+ unsigned int i;
+
+ spin_lock(&ctx->napi_lock);
+ hash_for_each(ctx->napi_ht, i, e, node) {
+ if (time_after(jiffies, e->timeout)) {
+ list_del(&e->list);
+ hash_del_rcu(&e->node);
+ kfree_rcu(e, rcu);
+ }
+ }
+ spin_unlock(&ctx->napi_lock);
+}
+
+static inline void io_napi_remove_stale(struct io_ring_ctx *ctx, bool is_stale)
+{
+ if (is_stale)
+ __io_napi_remove_stale(ctx);
+}
+
+static inline bool io_napi_busy_loop_timeout(unsigned long start_time,
+ unsigned long bp_usec)
+{
+ if (bp_usec) {
+ unsigned long end_time = start_time + bp_usec;
+ unsigned long now = busy_loop_current_time();
+
+ return time_after(now, end_time);
+ }
+
+ return true;
+}
+
+static bool io_napi_busy_loop_should_end(void *data,
+ unsigned long start_time)
+{
+ struct io_wait_queue *iowq = data;
+
+ if (signal_pending(current))
+ return true;
+ if (io_should_wake(iowq))
+ return true;
+ if (io_napi_busy_loop_timeout(start_time, iowq->napi_busy_poll_to))
+ return true;
+
+ return false;
+}
+
+static bool __io_napi_do_busy_loop(struct io_ring_ctx *ctx,
+ void *loop_end_arg)
+{
+ struct io_napi_entry *e;
+ bool (*loop_end)(void *, unsigned long) = NULL;
+ bool is_stale = false;
+
+ if (loop_end_arg)
+ loop_end = io_napi_busy_loop_should_end;
+
+ list_for_each_entry_rcu(e, &ctx->napi_list, list) {
+ napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg,
+ ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET);
+
+ if (time_after(jiffies, e->timeout))
+ is_stale = true;
+ }
+
+ return is_stale;
+}
+
+static void io_napi_blocking_busy_loop(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq)
+{
+ unsigned long start_time = busy_loop_current_time();
+ void *loop_end_arg = NULL;
+ bool is_stale = false;
+
+ /* Singular lists use a different napi loop end check function and are
+ * only executed once.
+ */
+ if (list_is_singular(&ctx->napi_list))
+ loop_end_arg = iowq;
+
+ rcu_read_lock();
+ do {
+ is_stale = __io_napi_do_busy_loop(ctx, loop_end_arg);
+ } while (!io_napi_busy_loop_should_end(iowq, start_time) && !loop_end_arg);
+ rcu_read_unlock();
+
+ io_napi_remove_stale(ctx, is_stale);
+}
+
+/*
+ * io_napi_init() - Init napi settings
+ * @ctx: pointer to io-uring context structure
+ *
+ * Init napi settings in the io-uring context.
+ */
+void io_napi_init(struct io_ring_ctx *ctx)
+{
+ INIT_LIST_HEAD(&ctx->napi_list);
+ spin_lock_init(&ctx->napi_lock);
+ ctx->napi_prefer_busy_poll = false;
+ ctx->napi_busy_poll_to = READ_ONCE(sysctl_net_busy_poll);
+}
+
+/*
+ * io_napi_free() - Deallocate napi
+ * @ctx: pointer to io-uring context structure
+ *
+ * Free the napi list and the hash table in the io-uring context.
+ */
+void io_napi_free(struct io_ring_ctx *ctx)
+{
+ struct io_napi_entry *e;
+ LIST_HEAD(napi_list);
+ unsigned int i;
+
+ spin_lock(&ctx->napi_lock);
+ hash_for_each(ctx->napi_ht, i, e, node) {
+ hash_del_rcu(&e->node);
+ kfree_rcu(e, rcu);
+ }
+ spin_unlock(&ctx->napi_lock);
+}
+
+/*
+ * __io_napi_adjust_timeout() - Add napi id to the busy poll list
+ * @ctx: pointer to io-uring context structure
+ * @iowq: pointer to io wait queue
+ * @ts: pointer to timespec or NULL
+ *
+ * Adjust the busy loop timeout according to timespec and busy poll timeout.
+ */
+void __io_napi_adjust_timeout(struct io_ring_ctx *ctx, struct io_wait_queue *iowq,
+ struct timespec64 *ts)
+{
+ unsigned int poll_to = READ_ONCE(ctx->napi_busy_poll_to);
+
+ if (ts) {
+ struct timespec64 poll_to_ts = ns_to_timespec64(1000 * (s64)poll_to);
+
+ if (timespec64_compare(ts, &poll_to_ts) > 0) {
+ *ts = timespec64_sub(*ts, poll_to_ts);
+ } else {
+ u64 to = timespec64_to_ns(ts);
+
+ do_div(to, 1000);
+ ts->tv_sec = 0;
+ ts->tv_nsec = 0;
+ }
+ }
+
+ iowq->napi_busy_poll_to = poll_to;
+}
+
+/*
+ * __io_napi_busy_loop() - execute busy poll loop
+ * @ctx: pointer to io-uring context structure
+ * @iowq: pointer to io wait queue
+ *
+ * Execute the busy poll loop and merge the spliced off list.
+ */
+void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq)
+{
+ iowq->napi_prefer_busy_poll = READ_ONCE(ctx->napi_prefer_busy_poll);
+
+ if (!(ctx->flags & IORING_SETUP_SQPOLL) && iowq->napi_busy_poll_to)
+ io_napi_blocking_busy_loop(ctx, iowq);
+}
+
+#endif
diff --git a/io_uring/napi.h b/io_uring/napi.h
new file mode 100644
index 0000000000000000000000000000000000000000..be8aa8ee32d9402119efd3c6b6c106a4e224a876
--- /dev/null
+++ b/io_uring/napi.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef IOU_NAPI_H
+#define IOU_NAPI_H
+
+#include <linux/kernel.h>
+#include <linux/io_uring.h>
+#include <net/busy_poll.h>
+
+#ifdef CONFIG_NET_RX_BUSY_POLL
+
+void io_napi_init(struct io_ring_ctx *ctx);
+void io_napi_free(struct io_ring_ctx *ctx);
+
+void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock);
+
+void __io_napi_adjust_timeout(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq, struct timespec64 *ts);
+void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq);
+
+static inline bool io_napi(struct io_ring_ctx *ctx)
+{
+ return !list_empty(&ctx->napi_list);
+}
+
+static inline void io_napi_adjust_timeout(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq,
+ struct timespec64 *ts)
+{
+ if (!io_napi(ctx))
+ return;
+ __io_napi_adjust_timeout(ctx, iowq, ts);
+}
+
+static inline void io_napi_busy_loop(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq)
+{
+ if (!io_napi(ctx))
+ return;
+ __io_napi_busy_loop(ctx, iowq);
+}
+
+/*
+ * io_napi_add() - Add napi id to the busy poll list
+ * @req: pointer to io_kiocb request
+ *
+ * Add the napi id of the socket to the napi busy poll list and hash table.
+ */
+static inline void io_napi_add(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct socket *sock;
+
+ if (!READ_ONCE(ctx->napi_busy_poll_to))
+ return;
+
+ sock = sock_from_file(req->file);
+ if (sock)
+ __io_napi_add(ctx, sock);
+}
+
+#else
+
+static inline void io_napi_init(struct io_ring_ctx *ctx)
+{
+}
+static inline void io_napi_free(struct io_ring_ctx *ctx)
+{
+}
+static inline bool io_napi(struct io_ring_ctx *ctx)
+{
+ return false;
+}
+static inline void io_napi_add(struct io_kiocb *req)
+{
+}
+static inline void io_napi_adjust_timeout(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq,
+ struct timespec64 *ts)
+{
+}
+static inline void io_napi_busy_loop(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq)
+{
+}
+
+#endif /* CONFIG_NET_RX_BUSY_POLL */
+
+#endif
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 8e01c2672df460791ab993e337dd1546490a8daf..053d738c330c6ddf57249421bfe30c1d31466e4f 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -15,6 +15,7 @@
#include "io_uring.h"
#include "refs.h"
+#include "napi.h"
#include "opdef.h"
#include "kbuf.h"
#include "poll.h"
@@ -649,6 +650,7 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
__io_poll_execute(req, mask);
return 0;
}
+ io_napi_add(req);
if (ipt->owning) {
/*