> > +Every transmit and receive virtqueue needs to count its own packets and
> > should not be affected by notifications sent by other virtqueues.
>
> I find this slightly confusing in that it describes counting
> which we did not previously mention. and it is not virtqueue iself
> counting of course it is the device. We also need to
> rewrite to avoid "should" outside conformance sections.
> Also we do not have to count for each queue only
> where coalescing is enabled.
>
> I came up with
>
> Packets are counted separately for each transmit or receive virtqueue
> until max_packets is reached or until usecs elapsed since ....
>
>
> and here I am stuck. What does usecs mean exactly? since when?
I don't think we need the "until max_packets is reached or .." part.
"Packets are counted separately for each transmit or receive
virtqueue" seems good enough for me.
The "until max_packets is reached or until .." part is explained in
the TX/RX examples.
> we also have vring notication suppression we should
> explain it is kind of on top.
Mentioning in every example/explanation that we should send a
notification only if not suppressed by the driver may be too verbose
IMO.
The current approach ignores the notifications suppression, and adds
the following line in the conformance section:
A device SHOULD NOT send used buffer notifications to the driver, if
the notifications are suppressed as explained in \ref{sec:Basic
Facilities of a Virtio Device / Virtqueues / Used Buffer Notification
Suppression} ....
Don't you think that this covers all the scenarios in just one line?
But in order to be more consistent, I may need to remove the "if the
notifications are not suppressed by the driver" part from the
Notifications When Coalescing Parameters Change subparagraph.
> I also feel it would be helpful to say that e get 1 notification per
> max_packets or per usecs which ever is the smallest.
This is shown in the TX/RX examples, but maybe we can fix it as I'm
suggesting below.
>
>
> > +
> > \subparagraph{RX Notifications}\label{sec:Device Types / Network Device /
> > Device Operation / Control Virtqueue / Notifications Coalescing / RX
> > Notifications}
> >
> > If, for example:
> > \begin{itemize}
> > -\item \field{rx_usecs} = 10.
> > -\item \field{rx_max_packets} = 15.
> > +\item \field{usecs} = 10.
> > +\item \field{max_packets} = 15.
> > \end{itemize}
> >
> > -The device will operate as follows:
> > +A device with a single receive virtqueue 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.
> > @@ -1564,17 +1564,24 @@ \subsubsection{Control Virtqueue}\label{sec:Device
> > Types / Network Device / Devi
> >
> > If, for example:
> > \begin{itemize}
> > -\item \field{tx_usecs} = 10.
> > -\item \field{tx_max_packets} = 15.
> > +\item \field{usecs} = 10.
> > +\item \field{max_packets} = 15.
> > \end{itemize}
> >
> > -The device will operate as follows:
> > +A device with a single transmit virtqueue 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 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}
> >
> > +\subparagraph{Notifications When Coalescing Parameters
> > Change}\label{sec:Device Types / Network Device / Device Operation /
> > Control Virtqueue / Notifications Coalescing / Notifications When
> > Coalescing Parameters Change}
> > +
> > +When a device changes the coalescing parameters, it needs to check if the
> > new coalescing parameters are met and send a used buffer notification if so.
>
> I feel we still need to clarify "met" here please. Or add a conformance
> statement defining this more formally.
>
How about adding the following line in the main paragraph:
Coalescing parameters are met when the number of sent/received packets
reaches \field{tx_max_packets} since the last used buffer
notification, or when \field{usecs} elapses since the last used buffer
notification, whichever comes first.
And adding the following line in the conformance section:
A device SHOULD NOT send a used buffer notification if \field{usecs}
elapsed since the last used buffer notification and no packets have
been received.
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
