[PATCH v3 03/17] perf ftrace: add option -t/--tid to filter by thread id

[Changbin Du]

This allows us to trace single thread instead of the whole process.

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
 tools/perf/Documentation/perf-ftrace.txt | 4 ++++
 tools/perf/builtin-ftrace.c              | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index d79560dea19f..e204bf6d50d8 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -38,6 +38,10 @@ OPTIONS
 --pid=::
 	Trace on existing process id (comma separated list).
 
+-t::
+--tid=::
+	Trace on existing thread id (comma separated list).
+
 -a::
 --all-cpus::
 	Force system-wide collection.  Scripts run without a <command>
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 244cc8e6bd60..1188b82c6541 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -515,6 +515,8 @@ int cmd_ftrace(int argc, const char **argv)
 		    "Show available functions to filter"),
 	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
 		   "trace on existing process id"),
+	OPT_STRING('t', "tid", &ftrace.target.tid, "tid",
+		   "trace on existing thread id (exclusive to --pid)"),
 	OPT_INCR('v', "verbose", &verbose,
 		 "be more verbose"),
 	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
-- 
2.25.1