[3/4] trace-cmd show: Add option to read buffer_percent

Commit Message

Steven Rostedt Dec. 29, 2023, 3:16 a.m. UTC

From: "Steven Rostedt (Google)" <[e-mail]>

Add trace-cmd show --buffer_percent to show the value of the buffer_percent
file.

Signed-off-by: Steven Rostedt (Google) <[e-mail]>
---
 Documentation/trace-cmd/trace-cmd-show.1.txt | 8 ++++++++
 tracecmd/trace-show.c                        | 6 ++++++
 tracecmd/trace-usage.c                       | 1 +
 3 files changed, 15 insertions(+)

Patch

diff --git a/Documentation/trace-cmd/trace-cmd-show.1.txt b/Documentation/trace-cmd/trace-cmd-show.1.txt
index ac40dacf7061..f85c070b0598 100644
--- a/Documentation/trace-cmd/trace-cmd-show.1.txt
+++ b/Documentation/trace-cmd/trace-cmd-show.1.txt
@@ -65,6 +65,14 @@  OPTIONS
      The ring buffer is broken up into equal size sub-buffers were an event can only
      be as big as the sub-buffer data section (the size minus its meta data).
 
+*--buffer_percent*::
+    Show the percentage the buffer must be filled before a reader that is blocked
+    on the trace_pipe_raw file will be woken up.
+
+  0       : wake up immediately on any new data
+  1 - 99  : wake up on this percentage of the sub-buffers being full
+  100     : wake up after the buffer is full and the writer is on the last sub-buffer
+
 *--ftrace_filter*::
      Show what function filters are set.
 
diff --git a/tracecmd/trace-show.c b/tracecmd/trace-show.c
index 17eb098952f7..d91362e47c50 100644
--- a/tracecmd/trace-show.c
+++ b/tracecmd/trace-show.c
@@ -20,6 +20,7 @@  enum {
 	OPT_buffer_subbuf_size_kb,
 	OPT_buffer_total_size_kb,
 	OPT_buffer_size_kb,
+	OPT_buffer_percent,
 	OPT_current_tracer,
 	OPT_tracing_on,
 };
@@ -44,6 +45,7 @@  void trace_show(int argc, char **argv)
 		{"buffer_size", no_argument, NULL, OPT_buffer_size_kb},
 		{"buffer_total_size", no_argument, NULL, OPT_buffer_total_size_kb},
 		{"buffer_subbuf_size", no_argument, NULL, OPT_buffer_subbuf_size_kb},
+		{"buffer_percent", no_argument, NULL, OPT_buffer_percent},
 		{"ftrace_filter", no_argument, NULL, OPT_ftrace_filter},
 		{"ftrace_notrace", no_argument, NULL, OPT_ftrace_notrace},
 		{"ftrace_pid", no_argument, NULL, OPT_ftrace_pid},
@@ -108,6 +110,10 @@  void trace_show(int argc, char **argv)
 			show_instance_file(instance, "buffer_subbuf_size_kb");
 			stop = 1;
 			break;
+		case OPT_buffer_percent:
+			show_instance_file(instance, "buffer_percent");
+			stop = 1;
+			break;
 		case OPT_ftrace_filter:
 			show_instance_file(instance, "set_ftrace_filter");
 			stop = 1;
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 7dc9b1871398..3e5456d27e3d 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -181,6 +181,7 @@  static struct usage_help usage_help[] = {
 		"          --buffer_size (for buffer_size_kb)\n"
 		"          --buffer_total_size (for buffer_total_size_kb)\n"
 		"          --buffer_subbuf_size (for buffer_subbuf_size_kb)\n"
+		"          --buffer_percent (for buffer_percent)\n"
 		"          --ftrace_filter (for set_ftrace_filter)\n"
 		"          --ftrace_notrace (for set_ftrace_notrace)\n"
 		"          --ftrace_pid (for set_ftrace_pid)\n"