From: Todd Brandt <[email protected]> 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.
Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Todd Brandt <[email protected]> [ changed comments about debugfs to tracefs ] Signed-off-by: Steven Rostedt (VMware) <[email protected]> --- 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 21e2d8863705..1c9016b27ee9 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1173,6 +1173,12 @@ 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 tracefs 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 44122e7a6418..d129ae51329a 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; -- 2.10.2
