[tip:perf/urgent] perf record: Clarify help for --switch-output

[tip-bot for Andi Kleen <tipbot@zytor.com>]

Commit-ID:  c38dab7df7ee4fdecd51e390d4d33d5ef5cff49d
Gitweb:     https://git.kernel.org/tip/c38dab7df7ee4fdecd51e390d4d33d5ef5cff49d
Author:     Andi Kleen <ak@linux.intel.com>
AuthorDate: Thu, 14 Mar 2019 15:49:56 -0700
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 19 Mar 2019 16:15:42 -0300

perf record: Clarify help for --switch-output

The help description for --switch-output looks like there are multiple
comma separated fields. But it's actually a choice of different options.
Make it clear and less confusing.

Before:

  % perf record -h
  ...
          --switch-output[=<signal,size,time>]
                            Switch output when receive SIGUSR2 or cross size,time threshold

After:

  % perf record -h
  ...

          --switch-output[=<signal or size[BKMG] or time[smhd]>]
                            Switch output when receiving SIGUSR2 (signal) or cross a size or time threshold

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
LPU-Reference: 20190314225002.30108-4-andi@firstfloor.org
Link: https://lkml.kernel.org/n/tip-9yecyuha04nyg8toyd1b2pgi@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-record.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 02d7c40b2d10..e7144a1c1c82 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1989,8 +1989,8 @@ static struct option __record_options[] = {
 	OPT_BOOLEAN(0, "timestamp-boundary", &record.timestamp_boundary,
 		    "Record timestamp boundary (time of first/last samples)"),
 	OPT_STRING_OPTARG_SET(0, "switch-output", &record.switch_output.str,
-			  &record.switch_output.set, "signal,size,time",
-			  "Switch output when receive SIGUSR2 or cross size,time threshold",
+			  &record.switch_output.set, "signal or size[BKMG] or time[smhd]",
+			  "Switch output when receiving SIGUSR2 (signal) or cross a size or time threshold",
 			  "signal"),
 	OPT_INTEGER(0, "switch-max-files", &record.switch_output.num_files,
 		   "Limit number of switch output generated files"),