[tip:perf/urgent] perf record: Fix --switch-output documentation and comment

[tip-bot for Jiri Olsa]

Commit-ID:  60437ac02f398e0ee0927748d4798dd5534ac90d
Gitweb:     http://git.kernel.org/tip/60437ac02f398e0ee0927748d4798dd5534ac90d
Author:     Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Tue, 3 Jan 2017 09:19:56 +0100
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 3 Jan 2017 11:11:38 -0300

perf record: Fix --switch-output documentation and comment

There's no --signal-trigger option, also adding the code comment into
record man page.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1483431600-19887-4-git-send-email-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/Documentation/perf-record.txt | 4 ++++
 tools/perf/builtin-record.c              | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 27fc361..5054d91 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -430,6 +430,10 @@ that gets then processed, possibly via a perf script, to decide if that
 particular perf.data snapshot should be kept or not.
 
 Implies --timestamp-filename, --no-buildid and --no-buildid-cache.
+The reason for the latter two is to reduce the data file switching
+overhead. You can still switch them on with:
+
+  --switch-output --no-no-buildid  --no-no-buildid-cache
 
 --dry-run::
 Parse options then exit. --dry-run can be used to detect errors in cmdline
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 31cf0ce..4ec10e9 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1636,7 +1636,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 		 * overhead. Still generate buildid if they are required
 		 * explicitly using
 		 *
-		 *  perf record --signal-trigger --no-no-buildid \
+		 *  perf record --switch-output --no-no-buildid \
 		 *              --no-no-buildid-cache
 		 *
 		 * Following code equals to: