Commit 65a50c65 authored by Todd Brandt's avatar Todd Brandt Committed by Steven Rostedt (VMware)
Browse files

ftrace/graph: Add ftrace_graph_max_depth kernel parameter

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 tracefs.


Signed-off-by: default avatarTodd Brandt <>
[ changed comments about debugfs to tracefs ]
Signed-off-by: default avatarSteven Rostedt (VMware) <>
parent bf7165cf
......@@ -1173,6 +1173,12 @@
functions that can be changed at run time by the
set_graph_notrace file in the debugfs tracing directory.
[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 tracefs tracing directory. default: 0 (no limit)[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
......@@ -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;
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