I've just realized that help message in a subcommand didn't show one
in the parent command. Since the option parser understands the parent,
display code should do the same. For example, `perf ftrace latency -h`
should show options in the `perf ftrace` command too.
Before:
$ perf ftrace latency -h
Usage: perf ftrace [<options>] [<command>]
or: perf ftrace [<options>] -- [<command>] [<options>]
or: perf ftrace {trace|latency} [<options>] [<command>]
or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]
-b, --use-bpf Use BPF to measure function latency
-n, --use-nsec Use nano-second histogram
-T, --trace-funcs <func>
Show latency of given function
After:
$ perf ftrace latency -h
Usage: perf ftrace [<options>] [<command>]
or: perf ftrace [<options>] -- [<command>] [<options>]
or: perf ftrace {trace|latency} [<options>] [<command>]
or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]
-a, --all-cpus System-wide collection from all CPUs
-b, --use-bpf Use BPF to measure function latency
-C, --cpu <cpu> List of cpus to monitor
-n, --use-nsec Use nano-second histogram
-p, --pid <pid> Trace on existing process id
-T, --trace-funcs <func>
Show latency of given function
-v, --verbose Be more verbose
--tid <tid> Trace on existing thread id (exclusive to --pid)
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240429233707.1511175-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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