1TAPRIO(8)                            Linux                           TAPRIO(8)
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NAME

6       TAPRIO - Time Aware Priority Shaper
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SYNOPSIS

9       tc qdisc ... dev dev parent classid [ handle major: ] taprio num_tc tcs
10               map P0 P1 P2 ...  queues count1@offset1 count2@offset2 ...
11               base-time base-time clockid clockid
12               sched-entry <command 1> <gate mask 1> <interval 1>
13               sched-entry <command 2> <gate mask 2> <interval 2>
14               sched-entry <command 3> <gate mask 3> <interval 3>
15               sched-entry <command N> <gate mask N> <interval N>
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DESCRIPTION

19       The  TAPRIO  qdisc  implements  a  simplified version of the scheduling
20       state machine defined by IEEE 802.1Q-2018 Section 8.6.9,  which  allows
21       configuration  of  a  sequence  of  gate  states, where each gate state
22       allows outgoing traffic for a subset  (potentially  empty)  of  traffic
23       classes.
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25       How  traffic  is  mapped  to  different  hardware  queues is similar to
26       mqprio(8) and so the map and queues parameters have the same meaning.
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28       The other parameters specify the schedule, and at what point in time it
29       should start (it can behave as the schedule started in the past).
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PARAMETERS

33       num_tc  Number of traffic classes to use. Up to 16 classes supported.
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36       map
37              The  priority  to  traffic class map. Maps priorities 0..15 to a
38              specified traffic class. See mqprio(8) for more details.
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41       queues
42              Provide count and offset of queue range for each traffic  class.
43              In  the  format,  count@offset.   Queue  ranges for each traffic
44              classes cannot overlap and must be a contiguous range of queues.
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47       base-time
48              Specifies the instant in nanoseconds,  using  the  reference  of
49              clockid,  defining  the time when the schedule starts. If 'base-
50              time' is a time in the past, the schedule will start at
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52              base-time + (N * cycle-time)
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54              where N is the smallest integer so the resulting time is greater
55              than  "now", and "cycle-time" is the sum of all the intervals of
56              the entries in the schedule;
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59       clockid
60              Specifies the clock to be used by  qdisc's  internal  timer  for
61              measuring time and scheduling events.
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64       sched-entry
65              There  may multiple sched-entry parameters in a single schedule.
66              Each one has the
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68              sched-entry <command> <gatemask> <interval>
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70              format. The only supported <command> is "S", which  means  "Set‐
71              GateStates",  following  the  IEEE 802.1Q-2018 definition (Table
72              8-7). <gate mask> is a bitmask where each bit  is  a  associated
73              with a traffic class, so bit 0 (the least significant bit) being
74              "on" means that traffic class 0 is "active"  for  that  schedule
75              entry.   <interval>  is  a  time  duration, in nanoseconds, that
76              specifies for how long that state defined by <command> and <gate
77              mask> should be held before moving to the next entry.
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EXAMPLES

81       The  following example shows how an traffic schedule with three traffic
82       classes ("num_tc 3"), which are separated different traffic classes, we
83       are  going  to  call these TC 0, TC 1 and TC 2. We could read the "map"
84       parameter below as: traffic with priority 3 is classified as TC 0, pri‐
85       ority 2 is classified as TC 1 and the rest is classified as TC 2.
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87       The schedule will start at instant 1528743495910289987 using the refer‐
88       ence CLOCK_TAI. The schedule is composed of three entries each of 300us
89       duration.
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91       # tc qdisc replace dev eth0 parent root handle 100 taprio \
92                     num_tc 3 \
93                     map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
94                     queues 1@0 1@1 2@2 \
95                     base-time 1528743495910289987 \
96                     sched-entry S 01 300000 \
97                     sched-entry S 02 300000 \
98                     sched-entry S 04 300000 \
99                     clockid CLOCK_TAI
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AUTHORS

104       Vinicius Costa Gomes <vinicius.gomes@intel.com>
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108iproute2                         25 Sept 2018                        TAPRIO(8)
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