On Tue, Feb 07, 2023 at 07:16:34PM +0800, Heng Qi wrote: > Currently, the coalescing profile is directly applied to all queues. > This patch supports configuring the parameters for a specified queue. > > When the traffic between queues is unbalanced, for example, one queue > is busy and another queue is idle, then it will be very useful to > control coalescing parameters at the queue granularity.
ethtool does not support this though, does it? what's the plan? > Signed-off-by: Heng Qi <[email protected]> > Reviewed-by: Xuan Zhuo <[email protected]> What I dislike about this interface is that if VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated, then in the common case of same parameters for all queues driver has to issue multiple commands. I can see either a special vq index (0xffff ?) or a special command used to set it for all queues. > --- > content.tex | 49 ++++++++++++++++++++++++++++++++++++++++++------- > 1 file changed, 42 insertions(+), 7 deletions(-) > > diff --git a/content.tex b/content.tex > index e863709..049c0e4 100644 > --- a/content.tex > +++ b/content.tex > @@ -3084,6 +3084,9 @@ \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_PERQUEUE_NOTF_COAL(52)] Device supports per-queue > + notifications coalescing. > + > \item[VIRTIO_NET_F_NOTF_COAL(53)] Device supports notifications coalescing. > > \item[VIRTIO_NET_F_GUEST_USO4 (54)] Driver can receive USOv4 packets. > @@ -3140,6 +3143,7 @@ \subsubsection{Feature bit > requirements}\label{sec:Device Types / Network Device > \item[VIRTIO_NET_F_NOTF_COAL] Requires VIRTIO_NET_F_CTRL_VQ. > \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. > +\item[VIRTIO_NET_F_PERQUEUE_NOTF_COAL] Requires VIRTIO_NET_F_CTRL_VQ and > VIRTIO_NET_F_NOTF_COAL. > \end{description} > > \subsubsection{Legacy Interface: Feature bits}\label{sec:Device Types / > Network Device / Feature bits / Legacy Interface: Feature bits} > @@ -4488,16 +4492,21 @@ \subsubsection{Control Virtqueue}\label{sec:Device > Types / Network Device / Devi > > If the VIRTIO_NET_F_NOTF_COAL feature is negotiated, the driver can > send control commands for dynamically changing the coalescing parameters. > +If additionally VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated, the driver > +can send control commands to configure the coalescing parameters of a > +specified receiveq or transmitq. > > \begin{lstlisting} > struct virtio_net_ctrl_coal_rx { > le32 rx_max_packets; > le32 rx_usecs; > + le16 rx_qid; (Only if VIRTIO_NET_F_PERQUEUE_NOTF_COAL negotiated) > }; > > struct virtio_net_ctrl_coal_tx { > le32 tx_max_packets; > le32 tx_usecs; > + le16 tx_qid; (Only if VIRTIO_NET_F_PERQUEUE_NOTF_COAL negotiated) > }; > > #define VIRTIO_NET_CTRL_NOTF_COAL 6 I think it's a good idea to do this on top of Alvaro's patch unifying these two structures. > @@ -4507,17 +4516,34 @@ \subsubsection{Control Virtqueue}\label{sec:Device > Types / Network Device / Devi > > Coalescing parameters: > \begin{itemize} > -\item \field{rx_usecs}: Maximum number of usecs to delay a RX notification. > -\item \field{tx_usecs}: Maximum number of usecs to delay a TX notification. > +\item \field{rx_qid}: Index of which receiveq to change the coalescing > parameters. > + If the value is between 0 and 0x7FFF, it represents the index of the > specified > + receiveq. Otherwise, if the value is 0xFFFF, it indicates to change the > + coalescing parameters for all receiveqs. what if the index does not map to a receive queue? > +\item \field{tx_qid}: Index of which transmitq to change the coalescing > parameters. > + If the value is between 0 and 0x7FFF, it represents the index of the > specified > + transmitq. Otherwise, if the value is 0xFFFF, it indicates to change the > + coalescing parameters for all transmitqs. > +\item \field{rx_usecs}: Maximum number of usecs to delay a RX notification. > If additionally > + VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated, it works for the > specified recieveq > + or all receieveqs. > +\item \field{tx_usecs}: Maximum number of usecs to delay a TX notification. > If additionally > + VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated, it works for the > specified transmitq > + or all transmitqs. > \item \field{rx_max_packets}: Maximum number of packets to receive before a > RX notification. > + If additionally VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated, it works > for the > + specified receiveq or all receiveqs. > \item \field{tx_max_packets}: Maximum number of packets to send before a TX > notification. > + If additionally VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated, it works > for the > + specified transmitq or all transmitqs. > \end{itemize} > > - > The class VIRTIO_NET_CTRL_NOTF_COAL has 2 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_TX_SET: set the \field{tx_usecs} and > \field{tx_max_packets} parameters, > + and set the \field{tx_qid} if VIRTIO_NET_F_PERQUEUE_NOTF_COAL is > negotiated. > +\item VIRTIO_NET_CTRL_NOTF_COAL_RX_SET: set the \field{rx_usecs} and > \field{rx_max_packets} parameters, > + and set the \field{rx_qid} if VIRTIO_NET_F_PERQUEUE_NOTF_COAL is > negotiated. > \end{enumerate} > > \subparagraph{RX Notifications}\label{sec:Device Types / Network Device / > Device Operation / Control Virtqueue / Notifications Coalescing / RX > Notifications} > @@ -4531,7 +4557,11 @@ \subsubsection{Control Virtqueue}\label{sec:Device > Types / Network Device / Devi > The device will operate as follows: > > \begin{itemize} > -\item The device will count received packets until it accumulates 15, or > until 10 usecs elapsed since the first one was received. > +\item The device will count received packets until it accumulates 15, or > until > + 10 usecs elapsed since the first one was received. If additionally > + VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated: when \field{rx_qid} is > set > + to 0, the accumulation was only from the receiveq1; when \field{rx_qid} > is > + set to 0xFFFF, the accumulation was from all receiveqs. > \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 as long as the notifications are suppressed. > \end{itemize} > > @@ -4546,7 +4576,12 @@ \subsubsection{Control Virtqueue}\label{sec:Device > Types / Network Device / Devi > The device will operate as follows: > > \begin{itemize} > -\item The device will count sent packets until it accumulates 15, or until > 10 usecs elapsed since the first one was sent. > +\item The device will count sent packets on the transmitq1 until it > accumulates 15, > + or until 10 usecs elapsed since the first one was sent. If additionally > + VIRTIO_NET_F_PERQUEUE_NOTF_COAL is negotiated: when \field{tx_qid} is > set > + to 0, the accumulation was only from the transmitq1; when > \field{tx_qid} is > + set to 0xFFFF, the accumulation was from all transmitqs. > + > \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 as long as the notifications are suppressed. > \end{itemize} > > -- > 2.19.1.6.gb485710b > > > This publicly archived list offers a means to provide input to the > OASIS Virtual I/O Device (VIRTIO) TC. > > In order to verify user consent to the Feedback License terms and > to minimize spam in the list archive, subscription is required > before posting. > > Subscribe: [email protected] > Unsubscribe: [email protected] > List help: [email protected] > List archive: https://lists.oasis-open.org/archives/virtio-comment/ > Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf > List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists > Committee: https://www.oasis-open.org/committees/virtio/ > Join OASIS: https://www.oasis-open.org/join/ --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
