perf sched: Add 'perf sched trace', improve documentation
Alias 'perf sched trace' to 'perf trace', for workflow completeness.
Add a bit of documentation for perf sched.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
index 056320e..1ce7919 100644
--- a/tools/perf/Documentation/perf-sched.txt
+++ b/tools/perf/Documentation/perf-sched.txt
@@ -3,16 +3,32 @@
NAME
----
-perf-sched - Read perf.data (created by perf record) and display sched output
+perf-sched - Tool to trace/measure scheduler properties (latencies)
SYNOPSIS
--------
[verse]
-'perf sched' [-i <file> | --input=file] symbol_name
+'perf sched' {record|latency|replay|trace}
DESCRIPTION
-----------
-This command reads the input file and displays the latencies recorded.
+There's four variants of perf sched:
+
+ 'perf sched record <command>' to record the scheduling events
+ of an arbitrary workload.
+
+ 'perf sched latency' to report the per task scheduling latencies
+ and other scheduling properties of the workload.
+
+ 'perf sched trace' to see a detailed trace of the workload that
+ was recorded.
+
+ 'perf sched replay' to simulate the workload that was recorded
+ via perf sched record. (this is done by starting up mockup threads
+ that mimic the workload based on the events in the trace. These
+ threads can then replay the timings (CPU runtime and sleep patterns)
+ of the workload as it occured when it was recorded - and can repeat
+ it a number of times, measuring its performance.)
OPTIONS
-------
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index ede40c1..8db0fd2 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1597,7 +1597,7 @@
}
static const char * const sched_usage[] = {
- "perf sched [<options>] {record|latency|replay}",
+ "perf sched [<options>] {record|latency|replay|trace}",
NULL
};
@@ -1719,6 +1719,11 @@
usage_with_options(replay_usage, replay_options);
}
__cmd_replay();
+ } else if (!strcmp(argv[0], "trace")) {
+ /*
+ * Aliased to 'perf trace' for now:
+ */
+ return cmd_trace(argc, argv, prefix);
} else {
usage_with_options(sched_usage, sched_options);
}