1 .TH MQPRIO 8 "24 Sept 2013" "iproute2" "Linux"
3 MQPRIO \- Multiqueue Priority Qdisc (Offloaded Hardware QOS)
16 count1@offset1 count2@offset2 ...
25 min_rate1 min_rate2 ...
27 max_rate1 max_rate2 ...
32 The MQPRIO qdisc is a simple queuing discipline that allows mapping
33 traffic flows to hardware queue ranges using priorities and a configurable
34 priority to traffic class mapping. A traffic class in this context is
35 a set of contiguous qdisc classes which map 1:1 to a set of hardware
38 By default the qdisc allocates a pfifo qdisc (packet limited first in, first
39 out queue) per TX queue exposed by the lower layer device. Other queuing
40 disciplines may be added subsequently. Packets are enqueued using the
42 parameter and hashed across the indicated queues in the
46 By default these parameters are configured by the hardware
47 driver to match the hardware QOS structures.
50 mode supports full offload of the mqprio options, the traffic classes, the queue
51 configurations and QOS attributes to the hardware. Enabled hardware can provide
52 hardware QOS with the ability to steer traffic flows to designated traffic
53 classes provided by this qdisc. Hardware based QOS is configured using the
57 with minimum and maximum bandwidth rates can be used for setting
58 transmission rates on each traffic class. Also further qdiscs may be added
59 to the classes of MQPRIO to create more complex configurations.
62 On creation with 'tc qdisc add', eight traffic classes are created mapping
63 priorities 0..7 to traffic classes 0..7 and priorities greater than 7 to
64 traffic class 0. This requires base driver support and the creation will
65 fail on devices that do not support hardware QOS schemes.
67 These defaults can be overridden using the qdisc parameters. Providing
68 the 'hw 0' flag allows software to run without hardware coordination.
70 If hardware coordination is being used and arguments are provided that
71 the hardware can not support then an error is returned. For many users
72 hardware defaults should work reasonably well.
74 As one specific example numerous Ethernet cards support the 802.1Q
75 link strict priority transmission selection algorithm (TSA). MQPRIO
76 enabled hardware in conjunction with the classification methods below
77 can provide hardware offloaded support for this TSA.
80 Multiple methods are available to set the SKB priority which MQPRIO
81 uses to select which traffic class to enqueue the packet.
84 A process with sufficient privileges can encode the destination class
85 directly with SO_PRIORITY, see
88 with iptables/nftables
89 An iptables/nftables rule can be created to match traffic flows and
94 The net_prio cgroup can be used to set the priority of all sockets
95 belong to an application. See kernel and cgroup documentation for details.
100 Number of traffic classes to use. Up to 16 classes supported.
104 The priority to traffic class map. Maps priorities 0..15 to a specified
109 Provide count and offset of queue range for each traffic class. In the
112 Queue ranges for each traffic classes cannot overlap and must be a
113 contiguous range of queues.
119 to support hardware offload. Set to
121 to configure user specified values in software only.
127 for full use of the mqprio options. Use
129 to offload only TC values and use hardware QOS defaults. Supported with 'hw'
136 to set bandwidth rate limits for a traffic class. Use
138 for hardware QOS defaults. Supported with 'hw' set to 1 only.
142 Minimum value of bandwidth rate limit for a traffic class.
146 Maximum value of bandwidth rate limit for a traffic class.
150 John Fastabend, <john.r.fastabend@intel.com>