Lines Matching refs:latency
23 There's latency tracing to examine what occurs between interrupts
130 Some of the tracers record the max latency.
135 latency is greater than the value in this
140 Some latency tracers will record a trace whenever the
141 latency is greater than the number in this file.
514 the trace with the longest max latency.
517 trace with the latency-format option enabled.
532 Traces and records the max latency that it takes for
539 Traces and records the max latency that it takes for just
594 PID "1977", the CPU that it was running on "000", the latency format
603 When the latency-format option is enabled or when one of the latency
605 why a latency happened. Here is a typical trace.
609 # irqsoff latency trace v1.1.5 on 3.8.0-test+
611 # latency: 259 us, #4/4, CPU#2 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
646 (3.10). Then it displays the max latency in microseconds (259 us). The number
651 The task is the process that was running when the latency
690 time: When the latency-format option is enabled, the trace file
692 trace. This differs from the output when latency-format
709 Note, the latency tracers will usually end with a back trace
710 to easily find where the latency occurred.
737 latency-format
783 latency-format option is enabled.
849 latency-format - This option changes the trace. When
901 function-trace - The latency tracers will enable function tracing
903 it is disabled, the latency tracers do not trace
905 when performing latency tests.
918 the kernel know of a new mouse event. The result is a latency
922 disabled. When a new maximum latency is hit, the tracer saves
923 the trace leading up to that latency point so that every time a
940 # irqsoff latency trace v1.1.5 on 3.8.0-test+
942 # latency: 16 us, #4/4, CPU#0 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
977 Here we see that that we had a latency of 16 microseconds (which is
981 between the time of recording the max latency and the time of
982 recording the function that had that latency.
991 # irqsoff latency trace v1.1.5 on 3.8.0-test+
993 # latency: 71 us, #168/168, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1056 Here we traced a 71 microsecond latency. But we also see all the
1059 overhead may extend the latency times. But nevertheless, this
1072 Like the irqsoff tracer, it records the maximum latency for
1086 # preemptoff latency trace v1.1.5 on 3.8.0-test+
1088 # latency: 46 us, #4/4, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1123 # preemptoff latency trace v1.1.5 on 3.8.0-test+
1125 # latency: 83 us, #241/241, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1236 # preemptirqsoff latency trace v1.1.5 on 3.8.0-test+
1238 # latency: 100 us, #4/4, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1289 # preemptirqsoff latency trace v1.1.5 on 3.8.0-test+
1291 # latency: 161 us, #339/339, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1405 # wakeup latency trace v1.1.5 on 3.8.0-test+
1407 # latency: 15 us, #4/4, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1440 latency". I stress the point that this is about RT tasks. It is
1441 also important to know the scheduling latency of non-RT tasks,
1442 but the average schedule latency is better for non-RT tasks.
1446 Real-Time environments are interested in the worst case latency.
1447 That is the longest latency it takes for something to happen,
1449 only have a large latency once in a while, but that would not
1454 worst case latency of RT tasks (just run the normal wakeup
1473 # wakeup_rt latency trace v1.1.5 on 3.8.0-test+
1475 # latency: 5 us, #4/4, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1520 # wakeup_rt latency trace v1.1.5 on 3.8.0-test+
1522 # latency: 29 us, #85/85, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
1630 As function tracing can induce a much larger latency, but without
1631 seeing what happens within the latency it is hard to know what
1645 # wakeup_rt latency trace v1.1.5 on 3.8.0-test+
1647 # latency: 6 us, #12/12, CPU#2 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
2635 available to all non latency tracers. (Latency tracers which
2636 record max latency, such as "irqsoff" or "wakeup", can't use
2707 one of the latency tracers, you will get the following results.