perf record: Clarify help for --switch-output

Commit-ID:  c38dab7df7ee4fdecd51e390d4d33d5ef5cff49d
Gitweb:     https://git.kernel.org/tip/c38dab7df7ee4fdecd51e390d4d33d5ef5cff49d
Author:     Andi Kleen <[email protected]>
AuthorDate: Thu, 14 Mar 2019 15:49:56 -0700
Committer:  Arnaldo Carvalho de Melo <[email protected]>
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

LPU-Reference: [email protected]

---
 tools/perf/builtin-record.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 02d7c40b2d10..e7144a1c1c82 100644
@@ -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"),