[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <b84cfe4015184a54078813c2e951207317c47fce.1696745452.git.hengqi@linux.alibaba.com>
Date: Sun, 8 Oct 2023 14:27:39 +0800
From: Heng Qi <hengqi@...ux.alibaba.com>
To: netdev@...r.kernel.org,
virtualization@...ts.linux-foundation.org
Cc: Jason Wang <jasowang@...hat.com>,
"Michael S. Tsirkin" <mst@...hat.com>,
Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Jesper Dangaard Brouer <hawk@...nel.org>,
John Fastabend <john.fastabend@...il.com>
Subject: [PATCH v3 1/6] virtio-net: initially change the value of tx-frames
Background:
1. Commit 0c465be183c7 ("virtio_net: ethtool tx napi configuration") uses
tx-frames to toggle napi_tx (0 off and 1 on) if notification coalescing
is not supported.
2. Commit 31c03aef9bc2 ("virtio_net: enable napi_tx by default") enables
napi_tx for all txqs by default.
Status:
When virtio-net supports notification coalescing, after initialization,
tx-frames is 0 and napi_tx is true.
Problem:
When the user only wants to set rx coalescing params using
ethtool -C eth0 rx-usecs 10, or
ethtool -Q eth0 queue_mask 0x1 -C rx-usecs 10,
these cmds will carry tx-frames as 0, causing the napi_tx switching condition
is satisfied. Then the user gets:
netlink error: Device or resource busy.
The same happens when trying to set rx-frames, adaptive_rx, adaptive_tx...
How to fix:
When notification coalescing feature is negotiated, initially make the
value of tx-frames to be consistent with napi_tx.
For compatibility with the past, it is still supported to use tx-frames
to toggle napi_tx.
Reported-by: Xiaoming Zhao <zxm377917@...baba-inc.com>
Signed-off-by: Heng Qi <hengqi@...ux.alibaba.com>
Acked-by: Jason Wang <jasowang@...hat.com>
---
drivers/net/virtio_net.c | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index fe7f314d65c9..10878c9d430a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -4442,13 +4442,6 @@ static int virtnet_probe(struct virtio_device *vdev)
dev->xdp_features |= NETDEV_XDP_ACT_RX_SG;
}
- if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
- vi->intr_coal_rx.max_usecs = 0;
- vi->intr_coal_tx.max_usecs = 0;
- vi->intr_coal_tx.max_packets = 0;
- vi->intr_coal_rx.max_packets = 0;
- }
-
if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
vi->has_rss_hash_report = true;
@@ -4523,6 +4516,27 @@ static int virtnet_probe(struct virtio_device *vdev)
if (err)
goto free;
+ if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
+ vi->intr_coal_rx.max_usecs = 0;
+ vi->intr_coal_tx.max_usecs = 0;
+ vi->intr_coal_rx.max_packets = 0;
+
+ /* Keep the default values of the coalescing parameters
+ * aligned with the default napi_tx state.
+ */
+ if (vi->sq[0].napi.weight)
+ vi->intr_coal_tx.max_packets = 1;
+ else
+ vi->intr_coal_tx.max_packets = 0;
+ }
+
+ if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
+ /* The reason is the same as VIRTIO_NET_F_NOTF_COAL. */
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ if (vi->sq[i].napi.weight)
+ vi->sq[i].intr_coal.max_packets = 1;
+ }
+
#ifdef CONFIG_SYSFS
if (vi->mergeable_rx_bufs)
dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
--
2.19.1.6.gb485710b
Powered by blists - more mailing lists