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From: "Björn Töpel" <bjorn.topel@gmail.com>
To: netdev@vger.kernel.org, bpf@vger.kernel.org
Cc: "Björn Töpel" <bjorn.topel@intel.com>,
	magnus.karlsson@intel.com, ast@kernel.org, daniel@iogearbox.net,
	maciej.fijalkowski@intel.com, sridhar.samudrala@intel.com,
	jesse.brandeburg@intel.com, qi.z.zhang@intel.com,
	kuba@kernel.org, edumazet@google.com, jonathan.lemon@gmail.com,
	maximmi@nvidia.com
Subject: [PATCH bpf-next v4 05/10] xsk: add busy-poll support for {recv,send}msg()
Date: Mon, 30 Nov 2020 19:52:00 +0100	[thread overview]
Message-ID: <20201130185205.196029-6-bjorn.topel@gmail.com> (raw)
In-Reply-To: <20201130185205.196029-1-bjorn.topel@gmail.com>

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.

Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
---
 net/xdp/xsk.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index c72b4dba2878..a8501a5477cf 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


  parent reply	other threads:[~2020-11-30 18:54 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-30 18:51 [PATCH bpf-next v4 00/10] Introduce preferred busy-polling Björn Töpel
2020-11-30 18:51 ` [PATCH bpf-next v4 01/10] net: introduce " Björn Töpel
2020-11-30 18:51 ` [PATCH bpf-next v4 02/10] net: add SO_BUSY_POLL_BUDGET socket option Björn Töpel
2020-11-30 18:51 ` [PATCH bpf-next v4 03/10] xsk: add support for recvmsg() Björn Töpel
2020-11-30 18:51 ` [PATCH bpf-next v4 04/10] xsk: check need wakeup flag in sendmsg() Björn Töpel
2020-11-30 18:52 ` Björn Töpel [this message]
2020-11-30 18:52 ` [PATCH bpf-next v4 06/10] xsk: propagate napi_id to XDP socket Rx path Björn Töpel
2020-11-30 18:52 ` [PATCH bpf-next v4 07/10] samples/bpf: use recvfrom() in xdpsock/rxdrop Björn Töpel
2020-11-30 18:52 ` [PATCH bpf-next v4 08/10] samples/bpf: use recvfrom() in xdpsock/l2fwd Björn Töpel
2020-11-30 18:52 ` [PATCH bpf-next v4 09/10] samples/bpf: add busy-poll support to xdpsock Björn Töpel
2020-11-30 18:52 ` [PATCH bpf-next v4 10/10] samples/bpf: add option to set the busy-poll budget Björn Töpel
2020-11-30 23:30 ` [PATCH bpf-next v4 00/10] Introduce preferred busy-polling patchwork-bot+netdevbpf

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