tracing/function-graph-tracer: implement a print_headers function
Impact: provide trace headers to explain a bit the output
This patch implements the print_headers callback for the function graph
tracer. These headers are output according to the current trace options.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 32b7fb9..af60eef 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -570,11 +570,36 @@
}
}
+static void print_graph_headers(struct seq_file *s)
+{
+ /* 1st line */
+ seq_printf(s, "# ");
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
+ seq_printf(s, "CPU ");
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
+ seq_printf(s, "TASK/PID ");
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD)
+ seq_printf(s, "OVERHEAD/");
+ seq_printf(s, "DURATION FUNCTION CALLS\n");
+
+ /* 2nd line */
+ seq_printf(s, "# ");
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
+ seq_printf(s, "| ");
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
+ seq_printf(s, "| | ");
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+ seq_printf(s, "| ");
+ seq_printf(s, "| | | | |\n");
+ } else
+ seq_printf(s, " | | | | |\n");
+}
static struct tracer graph_trace __read_mostly = {
- .name = "function_graph",
- .init = graph_trace_init,
- .reset = graph_trace_reset,
- .print_line = print_graph_function,
+ .name = "function_graph",
+ .init = graph_trace_init,
+ .reset = graph_trace_reset,
+ .print_line = print_graph_function,
+ .print_header = print_graph_headers,
.flags = &tracer_flags,
};