diff mbox series

[bpf-next,v3,05/10] xsk: add busy-poll support for {recv,send}msg()

Message ID 20201119083024.119566-6-bjorn.topel@gmail.com
State Superseded
Headers show
Series [bpf-next,v3,01/10] net: introduce preferred busy-polling | expand

Commit Message

Björn Töpel Nov. 19, 2020, 8:30 a.m. UTC
From: Björn Töpel <bjorn.topel@intel.com>

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@intel.com>
---
 net/xdp/xsk.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

Comments

Magnus Karlsson Nov. 25, 2020, 7:58 a.m. UTC | #1
On Thu, Nov 19, 2020 at 9:33 AM Björn Töpel <bjorn.topel@gmail.com> wrote:
>

> From: Björn Töpel <bjorn.topel@intel.com>

>

> 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@intel.com>

> ---

>  net/xdp/xsk.c | 24 ++++++++++++++++++++++++

>  1 file changed, 24 insertions(+)


Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>


> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c

> index bf0f5c34af6c..ecc4579e41ee 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"

> @@ -517,6 +518,17 @@ 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);

> @@ -529,6 +541,12 @@ 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);

> @@ -550,6 +568,12 @@ 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

>
diff mbox series

Patch

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index bf0f5c34af6c..ecc4579e41ee 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"
@@ -517,6 +518,17 @@  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);
@@ -529,6 +541,12 @@  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);
@@ -550,6 +568,12 @@  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;