Early trace callgraphs can be extremely large on systems with
several seconds of boot time. The max_depth parameter limits how
deep the graph trace goes and reduces the output size. This
parameter is the same as the max_graph_depth file in debugfs.
Signed-off-by: Todd Brandt <todd.e.bra...@linux.intel.com>
---
Documentation/admin-guide/kernel-parameters.txt | 6 ++++++
kernel/trace/ftrace.c | 9 +++++++++
2 files changed, 15 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt
b/Documentation/admin-guide/kernel-parameters.txt
index 986e443..1a8575f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1183,6 +1183,12 @@
functions that can be changed at run time by the
set_graph_notrace file in the debugfs tracing directory.
+ ftrace_graph_max_depth=<uint>
+ [FTRACE] Used with the function graph tracer. This is
+ the max depth it will trace into a function. This value
+ can be changed at run time by the max_graph_depth file
+ in the debugfs tracing directory. default: 0 (no limit)
+
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 0c06093..fc6b024 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4415,6 +4415,15 @@ static int __init set_graph_notrace_function(char *str)
}
__setup("ftrace_graph_notrace=", set_graph_notrace_function);
+static int __init set_graph_max_depth_function(char *str)
+{
+ if (!str)
+ return 0;
+ fgraph_max_depth = simple_strtoul(str, NULL, 0);
+ return 1;
+}
+__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
+
static void __init set_ftrace_early_graph(char *buf, int enable)
{
int ret;
--
2.1.4
