[RFC v3 Optimizing veth xsk performance 6/9] veth: add ndo_xsk_wakeup callback for veth

From: Albert Huang
Date: Mon Aug 07 2023 - 23:21:34 EST


add ndo_xsk_wakeup callback for veth, this is used to
wakeup napi tx.

Signed-off-by: Albert Huang <huangjie.albert@xxxxxxxxxxxxx>
---
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