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Diffstat (limited to 'tools/perf/Documentation/perf-sched.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-sched.txt | 78 |
1 files changed, 76 insertions, 2 deletions
diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt index 1cc08cc47ac5..7775b1eb2bee 100644 --- a/tools/perf/Documentation/perf-sched.txt +++ b/tools/perf/Documentation/perf-sched.txt @@ -8,11 +8,11 @@ perf-sched - Tool to trace/measure scheduler properties (latencies) SYNOPSIS -------- [verse] -'perf sched' {record|latency|map|replay|script} +'perf sched' {record|latency|map|replay|script|timehist} DESCRIPTION ----------- -There are five variants of perf sched: +There are several variants of 'perf sched': 'perf sched record <command>' to record the scheduling events of an arbitrary workload. @@ -36,6 +36,30 @@ There are five variants of perf sched: are running on a CPU. A '*' denotes the CPU that had the event, and a dot signals an idle CPU. + 'perf sched timehist' provides an analysis of scheduling events. + + Example usage: + perf sched record -- sleep 1 + perf sched timehist + + By default it shows the individual schedule events, including the wait + time (time between sched-out and next sched-in events for the task), the + task scheduling delay (time between wakeup and actually running) and run + time for the task: + + time cpu task name wait time sch delay run time + [tid/pid] (msec) (msec) (msec) + -------------- ------ -------------------- --------- --------- --------- + 79371.874569 [0011] gcc[31949] 0.014 0.000 1.148 + 79371.874591 [0010] gcc[31951] 0.000 0.000 0.024 + 79371.874603 [0010] migration/10[59] 3.350 0.004 0.011 + 79371.874604 [0011] <idle> 1.148 0.000 0.035 + 79371.874723 [0005] <idle> 0.016 0.000 1.383 + 79371.874746 [0005] gcc[31949] 0.153 0.078 0.022 + ... + + Times are in msec.usec. + OPTIONS ------- -i:: @@ -66,6 +90,56 @@ OPTIONS for 'perf sched map' --color-pids:: Highlight the given pids. +OPTIONS for 'perf sched timehist' +--------------------------------- +-k:: +--vmlinux=<file>:: + vmlinux pathname + +--kallsyms=<file>:: + kallsyms pathname + +-g:: +--no-call-graph:: + Do not display call chains if present. + +--max-stack:: + Maximum number of functions to display in backtrace, default 5. + +-s:: +--summary:: + Show only a summary of scheduling by thread with min, max, and average + run times (in sec) and relative stddev. + +-S:: +--with-summary:: + Show all scheduling events followed by a summary by thread with min, + max, and average run times (in sec) and relative stddev. + +--symfs=<directory>:: + Look for files with symbols relative to this directory. + +-V:: +--cpu-visual:: + Show visual aid for sched switches by CPU: 'i' marks idle time, + 's' are scheduler events. + +-w:: +--wakeups:: + Show wakeup events. + +-M:: +--migrations:: + Show migration events. + +--time:: + Only analyze samples within given time window: <start>,<stop>. Times + have the format seconds.microseconds. If start is not given (i.e., time + string is ',x.y') then analysis starts at the beginning of the file. If + stop time is not given (i.e, time string is 'x.y,') then analysis goes + to end of file. + + SEE ALSO -------- linkperf:perf-record[1] |