[PATCH 4/4] perf record: Default -t option to no inheritance

[Adrian Hunter]

The change to per-cpu mmaps causes the -p, -t
and -u options now to have inheritance enabled
by default.  Change that back to no inheritance
but for the -t option only.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Requested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
 tools/perf/Documentation/perf-record.txt | 2 ++
 tools/perf/builtin-record.c              | 8 ++++++--
 tools/perf/perf.h                        | 1 +
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 6ac867e..c407897 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -57,6 +57,8 @@ OPTIONS
 -t::
 --tid=::
         Record events on existing thread ID (comma separated list).
+        This option also disables inheritance by default.  Enable it by adding
+        --inherit.
 
 -u::
 --uid=::
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index f5b18b8..65615a8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -843,8 +843,9 @@ const struct option record_options[] = {
 	OPT_U64('c', "count", &record.opts.user_interval, "event period to sample"),
 	OPT_STRING('o', "output", &record.file.path, "file",
 		    "output file name"),
-	OPT_BOOLEAN('i', "no-inherit", &record.opts.no_inherit,
-		    "child tasks do not inherit counters"),
+	OPT_BOOLEAN_SET('i', "no-inherit", &record.opts.no_inherit,
+			&record.opts.no_inherit_set,
+			"child tasks do not inherit counters"),
 	OPT_UINTEGER('F', "freq", &record.opts.user_freq, "profile at this frequency"),
 	OPT_CALLBACK('m', "mmap-pages", &record.opts.mmap_pages, "pages",
 		     "number of mmap data pages",
@@ -939,6 +940,9 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 		goto out_symbol_exit;
 	}
 
+	if (rec->opts.target.tid && !rec->opts.no_inherit_set)
+		rec->opts.no_inherit = true;
+
 	err = target__validate(&rec->opts.target);
 	if (err) {
 		target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index b079304..b23fed5 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -254,6 +254,7 @@ struct perf_record_opts {
 	bool	     inherit_stat;
 	bool	     no_delay;
 	bool	     no_inherit;
+	bool	     no_inherit_set;
 	bool	     no_samples;
 	bool	     raw_samples;
 	bool	     sample_address;
-- 
1.7.11.7

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