Queue disc #12

TommyPec · 2016-01-17T23:24:51Z

Sorry but I'm new to GitHub, and I wasn't able to comment the code in-line.
here are some comments:

Please change PacketWithHeader to PacketWithV4Header and PacketWithV6Header (less confusion).
ARP callbacks (and probably many more) had packets with headers. Now they are without. Restore the previous behavior, e.g., m_dropTrace (pending.first);
Why the changes to Ipv4Header::DscpTypeToString (DscpType dscp) ?
Ipv4Header::GetVersion (void) const - don't add zombies. An Ipv4Header version must be 4, the assert is there for a reason.
There's no need to add a function for this (unless it's virtual, and we could discuss also about this). Anyway, it's never used, so you can remove it.
Why the changes to Ipv4L3Protocol::m_txTrace, m_rxTrace, etc. ? Are they necessary ? (I suspect that the same traces have been changed to v6).
TypeId NetDeviceQueue::GetTypeId (void) - missing SetConstructor
NetDevice and NetDeviceQueue::DoDispose should be updated to unlink each other (circular Ptr are not good). Check with Valgrind
Wake -> WakeUp (e.g., "Wake Up Little Susie")
PointToPointNetDevice::Send - Ptr txq = GetTxQueue (0); - why it is hardcoded ? Is it possible to have more TxQueues ?
9b) Why the txq is stopped if it couldn't enqueue packets ?
Documentation: until now ns-3 only had Tx queues. Clarify the role and the effect of rx queues in TC.
QueueDiscContainer - const_iterator Iterator; <- change the name, if it's const call it ConstIterator (or something similar).
PfifoFastQueueDisc::GetTypeId (void) - missing SetGroup (check also others).
PfifoFastQueueDisc::Classify - Ipv6 code should be practically identical... copy paste it :P
PfifoFastQueueDisc (Doxygen in header) - same comments as I did to Tom's proposal about QoS marking: RFC is outdated and bits are wrong (they're 6, not 7).
QueueDiscItem::Print (std::ostream& os) const - explicit casts to int of m_protocol and m_txq. The ostram operator can (and will) try to print 'em as characters, messing up the output.
DoDispose is missing from many classes.

General comment: Did I miss something or the only NetDevice taking advantage of the new TC is PointToPoint so far ?

This patch adds a NetDeviceQueue class to store information about a single transmission queue of a network device. This class is meant to store the state of a transmission queue (i.e., whether the queue is stopped or not) and some data used by techniques such as Byte Queue Limits. Also, multi-queue aware queue discs can aggregate a child queue disc to an object of this class. These features (excluding BQL) are added in subsequent commits. The NetDevice class maintains a vector of NetDeviceQueue pointers, one for each transmission queue. A NetDevice constructor is added which creates a single transmission queue by default for every device. The number of transmission queues can be modified (by child classes) by calling NetDevice::SetTxQueuesN. Two public methods, GetTxQueue and GetTxQueuesN, are also added to the NetDevice class to return the i-th NetDeviceQueue and the number of transmission queues, respectively.

…the installed MAC For WifiNetDevices, the number of transmission queues is set when installing the MAC (in WifiNetDevice::SetMac), given that the number of queues is 4 if the MAC supports QoS and 1 otherwise.

Add public methods to the NetDeviceQueue class to start, stop or wake a transmission queue. These methods are primarily called by NetDevices, but can also be invoked by the network stack once techniques like BQL are implemented. An IsStopped method is also added to allow queue discs to check the current status of a transmission queue. A wake callback is provided, so that upper layers (queue discs) can be solicited to send packets down.

The (unique) transmission queue is stopped when enqueuing a packet fails, so that upper layers do not send other packets down. When a packet transmission is completed, if the queue is empty then wake the upper layers. If the queue was stopped, there is now room for another packet and hence wake the upper layers as well.

… a given packet This commit just adds a GetSelectedQueue method to the NetDevice class. This method is called by the Traffic Control layer before enqueuing a packet in the queue disc to determine in which transmission queue the device will enqueue the packet. Such information is exploited by multi-queue aware queue discs. By default, this function returns 0, so that single-queue devices do not need to be modified.

A QueueItem base class is introduced to represent the items stored in a Queue. The base class only contains a Ptr<Packet>. Derived classes can store additional information. DropTailQueue, RedQueue and CodelQueue, along with their examples and testsuits, have been adapted. Objects using such queues have been adapted too.

QueueDisc is a base class providing the interface and implementing the operations common to all the queueing disciplines. Child classes need to implement the methods used to enqueue a packet (DoEnqueue), dequeue a single packet (DoDequeue), get a copy of the next packet to extract (DoPeek), plus methods to classify enqueued packets in case they manage multiple queues internally.

...aggregated to the outgoing network device, if any. Otherwise, packets are sent directly to the device.

…m the queue disc When a packet is passed to the Traffic Control layer, the IPv{4,6} header has not been added yet. It will be added when the packet is dequeued from the queue disc.

Linux pfifo_fast is the default priority queue enabled on Linux systems. Packets are enqueued in three FIFO droptail queues according to three priority bands based on their Type of Service bits or DSCP bits.

Signed-off-by: Stefano Avallone <[email protected]>

natale-p and others added 21 commits January 15, 2016 14:33

Added Traffic Control Layer

187d091

Internet depends on traffic-control

eb9a024

Made public ProtocolHandlerEntry struct in node.h

262931f

Aggregate TrafficControlLayer on any Internet-enabled node

80baa0f

Aggregate TCLayer by default on tests

9285b11

Register callbacks on TCLayer and NetDevices, RX side

cbafa49

Use traffic-control to send packets

11f20e7

WifiNetDevices can return the number of transmission queues based on …

ef2c685

…the installed MAC For WifiNetDevices, the number of transmission queues is set when installing the MAC (in WifiNetDevice::SetMac), given that the number of queues is 4 if the MAC supports QoS and 1 otherwise.

The traffic control layer enqueues packets in the queue disc

6e6ba99

...aggregated to the outgoing network device, if any. Otherwise, packets are sent directly to the device.

Defer the addition of the IP header until the packet is extracted fro…

4dd14d5

…m the queue disc When a packet is passed to the Traffic Control layer, the IPv{4,6} header has not been added yet. It will be added when the packet is dequeued from the queue disc.

Ipv4Header: Add GetVersion and make DscpTypeToString static

9881fe5

Add the pfifo_fast queue disc

106f8f2

Linux pfifo_fast is the default priority queue enabled on Linux systems. Packets are enqueued in three FIFO droptail queues according to three priority bands based on their Type of Service bits or DSCP bits.

Add a queue disc helper to ease the installation of queue discs

7d99326

Add a traffic control example

d850946

Signed-off-by: Stefano Avallone <[email protected]>

Add a pfifo_fast test suite

0815e6b

stavallo deleted the queue-disc branch February 25, 2016 22:58

TommyPec closed this Jun 27, 2017

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Queue disc #12

Queue disc #12

Uh oh!

TommyPec commented Jan 17, 2016

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Queue disc #12

Queue disc #12

Uh oh!

Conversation

TommyPec commented Jan 17, 2016

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants