[RESEND PATCH] perf ftrace: Add -O option to set trace option

From: changbin . du
Date: Fri Oct 13 2017 - 06:26:31 EST


From: Changbin Du <changbin.du@xxxxxxxxx>

There are some trace options to control what gets printed in the trace
output or manipulate the tracers. This patch add a commandline option
to set it.

Example:
perf ftrace -t function -O noprint-parent --trace-funcs "__kmalloc" -a
Xorg-1874 [002] .... 4107.182911: __kmalloc
Xorg-1874 [002] .... 4107.182920: __kmalloc

perf ftrace -t function -O print-parent --trace-funcs "__kmalloc" -a
Xorg-1874 [000] .... 3924.917243: __kmalloc <-drm_atomic_state_init
Xorg-1874 [000] .... 3924.917251: __kmalloc <-drm_atomic_state_init

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
tools/perf/builtin-ftrace.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 25a42ac..8b473e2 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -36,6 +36,7 @@ struct perf_ftrace {
struct list_head graph_funcs;
struct list_head nograph_funcs;
int graph_depth;
+ const char *trace_option;
};

struct filter_entry {
@@ -261,6 +262,17 @@ static int set_tracing_depth(struct perf_ftrace *ftrace)
return 0;
}

+static int set_tracing_option(struct perf_ftrace *ftrace)
+{
+ if (ftrace->trace_option == NULL)
+ return 0;
+
+ if (write_tracing_file("trace_options", ftrace->trace_option) < 0)
+ return -1;
+
+ return 0;
+}
+
static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
{
char *trace_file;
@@ -313,6 +325,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
goto out_reset;
}

+ if (set_tracing_option(ftrace) < 0) {
+ pr_err("failed to set trace option\n");
+ goto out_reset;
+ }
+
if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
goto out_reset;
@@ -456,6 +473,8 @@ int cmd_ftrace(int argc, const char **argv)
"Set nograph filter on given functions", parse_filter_func),
OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
"Max depth for function graph tracer"),
+ OPT_STRING('O', "trace-option", &ftrace.trace_option, "option",
+ "Set a trace option"),
OPT_END()
};

--
2.7.4