From: Björn Töpel <bjorn.topel@xxxxxxxxx>
Wire-up XDP socket busy-poll support for recvmsg() and sendmsg(). If
the XDP socket prefers busy-polling, make sure that no wakeup/IPI is
performed.
Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
---
net/xdp/xsk.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 1cb04b5e4247..a71a14fedfec 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -23,6 +23,7 @@
#include <linux/netdevice.h>
#include <linux/rculist.h>
#include <net/xdp_sock_drv.h>
+#include <net/busy_poll.h>
#include <net/xdp.h>
#include "xsk_queue.h"
@@ -460,6 +461,17 @@ static int __xsk_sendmsg(struct sock *sk)
return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk);
}
+static bool xsk_no_wakeup(struct sock *sk)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ /* Prefer busy-polling, skip the wakeup. */
+ return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
+ READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
+#else
+ return false;
+#endif
+}
+
static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
{
bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
@@ -472,6 +484,12 @@ static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
if (unlikely(need_wait))
return -EOPNOTSUPP;
+ if (sk_can_busy_loop(sk))
+ sk_busy_loop(sk, 1); /* only support non-blocking sockets */
+
+ if (xsk_no_wakeup(sk))
+ return 0;
+
pool = xs->pool;
if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
return __xsk_sendmsg(sk);
@@ -493,6 +511,12 @@ static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int fl
if (unlikely(need_wait))
return -EOPNOTSUPP;
+ if (sk_can_busy_loop(sk))
+ sk_busy_loop(sk, 1); /* only support non-blocking sockets */
+
+ if (xsk_no_wakeup(sk))
+ return 0;
+
if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
return xsk_wakeup(xs, XDP_WAKEUP_RX);
return 0;
--
2.27.0
