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Commit 0d7d9a16 authored by Namhyung Kim's avatar Namhyung Kim Committed by Steven Rostedt
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tracing: Add ftrace_graph_notrace boot parameter 

The ftrace_graph_notrace option is for specifying notrace filter for
function graph tracer at boot time.  It can be altered after boot
using set_graph_notrace file on the debugfs.

Link: http://lkml.kernel.org/p/1402590233-22321-2-git-send-email-namhyung@kernel.org



Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 3448bac3

Documentation/kernel-parameters.txt

+6 −0
Original line number Diff line number Diff line
@@ -1097,6 +1097,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			that can be changed at run time by the

			set_graph_function file in the debugfs tracing directory.



	ftrace_graph_notrace=[function-list]

			[FTRACE] Do not trace from the functions specified in

			function-list.  This list is a comma separated list of

			functions that can be changed at run time by the

			set_graph_notrace file in the debugfs tracing directory.



	gamecon.map[2|3]=

			[HW,JOY] Multisystem joystick and NES/SNES/PSX pad

			support via parallel port (up to 5 devices per port)

kernel/trace/ftrace.c

+20 −4
Original line number Diff line number Diff line
@@ -3884,6 +3884,7 @@ __setup("ftrace_filter=", set_ftrace_filter); 


#ifdef CONFIG_FUNCTION_GRAPH_TRACER

static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;

static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;

static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);



static int __init set_graph_function(char *str)
@@ -3893,16 +3894,29 @@ static int __init set_graph_function(char *str) 
}

__setup("ftrace_graph_filter=", set_graph_function);



static void __init set_ftrace_early_graph(char *buf)

static int __init set_graph_notrace_function(char *str)

{

	strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);

	return 1;

}

__setup("ftrace_graph_notrace=", set_graph_notrace_function);



static void __init set_ftrace_early_graph(char *buf, int enable)

{

	int ret;

	char *func;

	unsigned long *table = ftrace_graph_funcs;

	int *count = &ftrace_graph_count;



	if (!enable) {

		table = ftrace_graph_notrace_funcs;

		count = &ftrace_graph_notrace_count;

	}



	while (buf) {

		func = strsep(&buf, ",");

		/* we allow only one expression at a time */

		ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,

				      FTRACE_GRAPH_MAX_FUNCS, func);

		ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func);

		if (ret)

			printk(KERN_DEBUG "ftrace: function %s not "

					  "traceable\n", func);
@@ -3931,7 +3945,9 @@ static void __init set_ftrace_early_filters(void) 
		ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	if (ftrace_graph_buf[0])

		set_ftrace_early_graph(ftrace_graph_buf);

		set_ftrace_early_graph(ftrace_graph_buf, 1);

	if (ftrace_graph_notrace_buf[0])

		set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

}