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tracing: Add ftrace_graph_notrace boot parameter

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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: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Namhyung Kim 2014-06-13 01:23:50 +09:00 committed by Steven Rostedt
parent 3448bac329
commit 0d7d9a16ce
2 changed files with 26 additions and 4 deletions
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6
Documentation/kernel-parameters.txt
View File

@ -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)

24
kernel/trace/ftrace.c
View File

@ -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 */
}