On Wed, 21 Dec 2022 12:17:29 +0200, Alvaro Karsz
wrote:
> This patch adds a new feature VIRTIO_NET_F_NOTF_COAL_LOW_HIGH,
> and adds 2 new commands to VIRTIO_NET_CTRL_NOTF_COAL class:
> * VIRTIO_NET_CTRL_NOTF_COAL_LOW_SET - create a low-rate set of
> coalescing parameters. the device should switch to this set when
> the packet rate (packets per second) reaches the pkt_rate_low
> threshold.
>
> * VIRTIO_NET_CTRL_NOTF_COAL_HIGH_SET - create a high-rate set of
> coalescing parameters. the device should switch to this set when
> the packet rate (packets per second) reaches the pkt_rate_high
> threshold.
>
> A device may have up to 3 sets, and should switch between them based on
> the packet rate.
I want to know which one is better than NetDim(Coalesce Adaptive) in driver.
I know Heng Qi's work in this.
Thanks
>
> Signed-off-by: Alvaro Karsz
> ---
> content.tex | 61 -
> 1 file changed, 60 insertions(+), 1 deletion(-)
>
> diff --git a/content.tex b/content.tex
> index 96f4723..969f945 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -3088,6 +3088,8 @@ \subsection{Feature bits}\label{sec:Device Types /
> Network Device / Feature bits
> \item[VIRTIO_NET_F_CTRL_MAC_ADDR(23)] Set MAC address through control
> channel.
>
> +\item[VIRTIO_NET_F_NOTF_COAL_LOW_HIGH(50)] Device supports notifications
> coalescing low rate and high rate sets.
> +
> \item[VIRTIO_NET_F_NOTF_COAL(53)] Device supports notifications coalescing.
>
> \item[VIRTIO_NET_F_GUEST_USO4 (54)] Driver can receive USOv4 packets.
> @@ -3142,6 +3144,7 @@ \subsubsection{Feature bit
> requirements}\label{sec:Device Types / Network Device
> \item[VIRTIO_NET_F_MQ] Requires VIRTIO_NET_F_CTRL_VQ.
> \item[VIRTIO_NET_F_CTRL_MAC_ADDR] Requires VIRTIO_NET_F_CTRL_VQ.
> \item[VIRTIO_NET_F_NOTF_COAL] Requires VIRTIO_NET_F_CTRL_VQ.
> +\item[VIRTIO_NET_F_NOTF_COAL_LOW_HIGH] Requires VIRTIO_NET_F_NOTF_COAL.
> \item[VIRTIO_NET_F_RSC_EXT] Requires VIRTIO_NET_F_HOST_TSO4 or
> VIRTIO_NET_F_HOST_TSO6.
> \item[VIRTIO_NET_F_RSS] Requires VIRTIO_NET_F_CTRL_VQ.
> \end{description}
> @@ -4504,9 +4507,25 @@ \subsubsection{Control Virtqueue}\label{sec:Device
> Types / Network Device / Devi
> le32 tx_usecs;
> };
>
> +//Only if VIRTIO_NET_F_NOTF_COAL_LOW_HIGH negotiated
> +struct virtio_net_ctrl_coal_low {
> +le32 pkt_rate_low;
> +struct virtio_net_ctrl_coal_tx tx;
> +struct virtio_net_ctrl_coal_rx rx;
> +};
> +
> +//Only if VIRTIO_NET_F_NOTF_COAL_LOW_HIGH negotiated
> +struct virtio_net_ctrl_coal_high {
> +le32 pkt_rate_high;
> +struct virtio_net_ctrl_coal_tx tx;
> +struct virtio_net_ctrl_coal_rx rx;
> +};
> +
> #define VIRTIO_NET_CTRL_NOTF_COAL 6
> #define VIRTIO_NET_CTRL_NOTF_COAL_TX_SET 0
> #define VIRTIO_NET_CTRL_NOTF_COAL_RX_SET 1
> + #define VIRTIO_NET_CTRL_NOTF_COAL_LOW_SET 2 //Only if
> VIRTIO_NET_F_NOTF_COAL_LOW_HIGH negotiated
> + #define VIRTIO_NET_CTRL_NOTF_COAL_HIGH_SET 3 //Only if
> VIRTIO_NET_F_NOTF_COAL_LOW_HIGH negotiated
> \end{lstlisting}
>
> Coalescing parameters:
> @@ -4515,13 +4534,17 @@ \subsubsection{Control Virtqueue}\label{sec:Device
> Types / Network Device / Devi
> \item \field{tx_usecs}: Maximum number of usecs to delay a TX notification.
> \item \field{rx_max_packets}: Maximum number of packets to receive before a
> RX notification.
> \item \field{tx_max_packets}: Maximum number of packets to send before a TX
> notification.
> +\item \field{pkt_rate_low}: Threshold for low packet rate set (packets per
> second).
> +\item \field{pkt_rate_high}: Threshold for high packet rate set (packets per
> second).
> \end{itemize}
>
>
> -The class VIRTIO_NET_CTRL_NOTF_COAL has 2 commands:
> +The class VIRTIO_NET_CTRL_NOTF_COAL has 4 commands:
> \begin{enumerate}
> \item VIRTIO_NET_CTRL_NOTF_COAL_TX_SET: set the \field{tx_usecs} and
> \field{tx_max_packets} parameters.
> \item VIRTIO_NET_CTRL_NOTF_COAL_RX_SET: set the \field{rx_usecs} and
> \field{rx_max_packets} parameters.
> +\item VIRTIO_NET_CTRL_NOTF_COAL_LOW_SET: set the \field{rx_usecs},
> \field{rx_max_packets}, \field{tx_usecs} and \field{tx_max_packets} set for a
> rate of \field{pkt_rate_low} or less packets per second.
> +\item VIRTIO_NET_CTRL_NOTF_COAL_HIGH_SET: set the \field{rx_usecs},
> \field{rx_max_packets}, \field{tx_usecs} and \field{tx_max_packets} set for a
> rate of \field{pkt_rate_high} or more packets per second.
> \end{enumerate}
>
> \subparagraph{RX Notifications}\label{sec:Device Types / Network Device /
> Device Operation / Control Virtqueue / Notifications Coalescing / RX
> Notifications}
> @@ -4554,18 +4577,54 @@ \subsubsection{Control Virtqueue}\label{sec:Device
> Types / Network Device / Devi
> \item If the notifications are not suppressed by the driver, the device will
> send an used buffer notification, otherwise, the device will not send an used
> buffer notification
