Re: [PATCH net-next V4 2/3] virtio_net: support per queue interrupt coalesce command
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2023-07-28 05:48:06
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On Thu, Jul 27, 2023 at 03:28:32PM +0200, Paolo Abeni wrote:
On Tue, 2023-07-25 at 16:07 +0300, Gavin Li wrote:quoted
Add interrupt_coalesce config in send_queue and receive_queue to cache user config. Send per virtqueue interrupt moderation config to underlying device in order to have more efficient interrupt moderation and cpu utilization of guest VM. Additionally, address all the VQs when updating the global configuration, as now the individual VQs configuration can diverge from the global configuration. Signed-off-by: Gavin Li <redacted> Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com> Reviewed-by: Jiri Pirko <redacted> Acked-by: Michael S. Tsirkin <mst@redhat.com>FTR, this patch is significantly different from the version previously acked/reviewed, I'm unsure if all the reviewers are ok with the new one. [...]
still ok by me Acked-by: Michael S. Tsirkin <mst@redhat.com> let's wait for Jason too.
quoted
static int virtnet_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec, struct kernel_ethtool_coalesce *kernel_coal, struct netlink_ext_ack *extack) { struct virtnet_info *vi = netdev_priv(dev); - int ret, i, napi_weight; + int ret, queue_number, napi_weight; bool update_napi = false; /* Can't change NAPI weight if the link is up */ napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0; - if (napi_weight ^ vi->sq[0].napi.weight) { - if (dev->flags & IFF_UP) - return -EBUSY; - else - update_napi = true; + for (queue_number = 0; queue_number < vi->max_queue_pairs; queue_number++) { + ret = virtnet_should_update_vq_weight(dev->flags, napi_weight, + vi->sq[queue_number].napi.weight, + &update_napi); + if (ret) + return ret; + + if (update_napi) { + /* All queues that belong to [queue_number, queue_count] will be + * updated for the sake of simplicity, which might not be necessaryIt looks like the comment above still refers to the old code. Should be: [queue_number, vi->max_queue_pairs] Otherwise LGTM, thanks! Paolo