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From:   Albert Huang <huangjie.albert@bytedance.com>
To:     davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com
Cc:     Albert Huang <huangjie.albert@bytedance.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn@kernel.org>,
        Magnus Karlsson <magnus.karlsson@intel.com>,
        Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
        Jonathan Lemon <jonathan.lemon@gmail.com>,
        Pavel Begunkov <asml.silence@gmail.com>,
        Yunsheng Lin <linyunsheng@huawei.com>,
        Kees Cook <keescook@chromium.org>,
        Richard Gobert <richardbgobert@gmail.com>,
        "open list:NETWORKING DRIVERS" <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:XDP (eXpress Data Path)" <bpf@vger.kernel.org>
Subject: [RFC v3 Optimizing veth xsk performance 6/9] veth: add ndo_xsk_wakeup callback for veth
Date:   Tue,  8 Aug 2023 11:19:10 +0800
Message-Id: <20230808031913.46965-7-huangjie.albert@bytedance.com>
In-Reply-To: <20230808031913.46965-1-huangjie.albert@bytedance.com>
References: <20230808031913.46965-1-huangjie.albert@bytedance.com>
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add ndo_xsk_wakeup callback for veth, this is used to
wakeup napi tx.

Signed-off-by: Albert Huang <huangjie.albert@bytedance.com>
---
 drivers/net/veth.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 28b891dd8dc9..ac78d6a87416 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1805,6 +1805,44 @@ static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
 	rcu_read_unlock();
 }
 
+static void veth_xsk_remote_trigger_napi(void *info)
+{
+	struct veth_sq *sq = info;
+
+	napi_schedule(&sq->xdp_napi);
+}
+
+static int veth_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag)
+{
+	struct veth_priv *priv;
+	struct veth_sq *sq;
+	u32 last_cpu, cur_cpu;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	if (qid >= dev->real_num_rx_queues)
+		return -EINVAL;
+
+	priv = netdev_priv(dev);
+	sq = &priv->sq[qid];
+
+	if (napi_if_scheduled_mark_missed(&sq->xdp_napi))
+		return 0;
+
+	last_cpu = sq->xsk.last_cpu;
+	cur_cpu = get_cpu();
+
+	/*  raise a napi */
+	if (last_cpu == cur_cpu)
+		napi_schedule(&sq->xdp_napi);
+	else
+		smp_call_function_single(last_cpu, veth_xsk_remote_trigger_napi, sq, true);
+
+	put_cpu();
+	return 0;
+}
+
 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 			struct netlink_ext_ack *extack)
 {
@@ -2019,6 +2057,7 @@ static const struct net_device_ops veth_netdev_ops = {
 	.ndo_set_rx_headroom	= veth_set_rx_headroom,
 	.ndo_bpf		= veth_xdp,
 	.ndo_xdp_xmit		= veth_ndo_xdp_xmit,
+	.ndo_xsk_wakeup		= veth_xsk_wakeup,
 	.ndo_get_peer_dev	= veth_peer_dev,
 };
 
-- 
2.20.1