xref: /linux/tools/perf/Documentation/perf-sched.txt (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1perf-sched(1)
2==============
3
4NAME
5----
6perf-sched - Tool to trace/measure scheduler properties (latencies)
7
8SYNOPSIS
9--------
10[verse]
11'perf sched' {record|latency|map|replay|script}
12
13DESCRIPTION
14-----------
15There are five variants of perf sched:
16
17  'perf sched record <command>' to record the scheduling events
18  of an arbitrary workload.
19
20  'perf sched latency' to report the per task scheduling latencies
21  and other scheduling properties of the workload.
22
23  'perf sched script' to see a detailed trace of the workload that
24   was recorded (aliased to 'perf script' for now).
25
26  'perf sched replay' to simulate the workload that was recorded
27  via perf sched record. (this is done by starting up mockup threads
28  that mimic the workload based on the events in the trace. These
29  threads can then replay the timings (CPU runtime and sleep patterns)
30  of the workload as it occurred when it was recorded - and can repeat
31  it a number of times, measuring its performance.)
32
33  'perf sched map' to print a textual context-switching outline of
34  workload captured via perf sched record.  Columns stand for
35  individual CPUs, and the two-letter shortcuts stand for tasks that
36  are running on a CPU. A '*' denotes the CPU that had the event, and
37  a dot signals an idle CPU.
38
39OPTIONS
40-------
41-i::
42--input=<file>::
43        Input file name. (default: perf.data unless stdin is a fifo)
44
45-v::
46--verbose::
47        Be more verbose. (show symbol address, etc)
48
49-D::
50--dump-raw-trace=::
51        Display verbose dump of the sched data.
52
53SEE ALSO
54--------
55linkperf:perf-record[1]
56