Subject: Re: [PATCH net-next 0/5] virtio-net: support dynamic coalescing moderation

From: "Michael S. Tsirkin" <[email-masked]>
Date: Wed, 25 Oct 2023 01:49:42 -0400

On Thu, Oct 12, 2023 at 03:44:04PM +0800, Heng Qi wrote:
> Now, virtio-net already supports per-queue moderation parameter
> setting. Based on this, we use the netdim library of linux to support
> dynamic coalescing moderation for virtio-net.
> 
> Due to hardware scheduling issues, we only tested rx dim.

So patches 1 to 4 look ok but patch 5 is untested - we should
probably wait until it's tested properly.

> @Test env
> rxq0 has affinity to cpu0.
> 
> @Test cmd
> client: taskset -c 0 sockperf tp -i ${IP} -t 30 --tcp -m ${msg_size}
> server: taskset -c 0 sockperf sr --tcp
> 
> @Test res
> The second column is the ratio of the result returned by client
> when rx dim is enabled to the result returned by client when
> rx dim is disabled.
> 	--------------------------------------
> 	| msg_size |  rx_dim=on / rx_dim=off |
> 	--------------------------------------
> 	|   14B    |         + 3%            |   
> 	--------------------------------------
> 	|   100B   |         + 16%           |
> 	--------------------------------------
> 	|   500B   |         + 25%           |
> 	--------------------------------------
> 	|   1400B  |         + 28%           |
> 	--------------------------------------
> 	|   2048B  |         + 22%           |
> 	--------------------------------------
> 	|   4096B  |         + 5%            |
> 	--------------------------------------
> 
> ---
> This patch set was part of the previous netdim patch set[1].
> [1] was split into a merged bugfix set[2] and the current set.
> The previous relevant commentators have been Cced.
> 
> [1] https://lore.kernel.org/all/[email-masked]/
> [2] https://lore.kernel.org/all/[email-masked]/
> 
> Heng Qi (5):
>   virtio-net: returns whether napi is complete
>   virtio-net: separate rx/tx coalescing moderation cmds
>   virtio-net: extract virtqueue coalescig cmd for reuse
>   virtio-net: support rx netdim
>   virtio-net: support tx netdim
> 
>  drivers/net/virtio_net.c | 394 ++++++++++++++++++++++++++++++++-------
>  1 file changed, 322 insertions(+), 72 deletions(-)
> 
> -- 
> 2.19.1.6.gb485710b