Re: [PATCH net-next v2 4/4] virtio_net: Use persistent NAPI config
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2025-01-16 07:56:57
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On Thu, 16 Jan 2025 05:52:59 +0000, Joe Damato [off-list ref] wrote:
Use persistent NAPI config so that NAPI IDs are not renumbered as queue
counts change.
$ sudo ethtool -l ens4 | tail -5 | egrep -i '(current|combined)'
Current hardware settings:
Combined: 4
$ ./tools/net/ynl/pyynl/cli.py \
--spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
{'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
{'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'type': 'tx'},
{'id': 1, 'ifindex': 2, 'type': 'tx'},
{'id': 2, 'ifindex': 2, 'type': 'tx'},
{'id': 3, 'ifindex': 2, 'type': 'tx'}]
Now adjust the queue count, note that the NAPI IDs are not renumbered:
$ sudo ethtool -L ens4 combined 1
$ ./tools/net/ynl/pyynl/cli.py \
--spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'type': 'tx'}]
$ sudo ethtool -L ens4 combined 8
$ ./tools/net/ynl/pyynl/cli.py \
--spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
{'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
{'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
{'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'rx'},
{'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'rx'},
{'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'rx'},
{'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'rx'},
[...]
Signed-off-by: Joe Damato <redacted>Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
quoted hunk ↗ jump to hunk
--- v2: - New in this v2. Adds persistent NAPI config so that NAPI IDs are not renumbered and napi_config settings are persisted. drivers/net/virtio_net.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index c6fda756dd07..52094596e94b 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c@@ -6420,8 +6420,9 @@ static int virtnet_alloc_queues(struct virtnet_info *vi) INIT_DELAYED_WORK(&vi->refill, refill_work); for (i = 0; i < vi->max_queue_pairs; i++) { vi->rq[i].pages = NULL; - netif_napi_add_weight(vi->dev, &vi->rq[i].napi, virtnet_poll, - napi_weight); + netif_napi_add_config(vi->dev, &vi->rq[i].napi, virtnet_poll, + i); + vi->rq[i].napi.weight = napi_weight; netif_napi_add_tx_weight(vi->dev, &vi->sq[i].napi, virtnet_poll_tx, napi_tx ? napi_weight : 0); --2.25.1