Author: Steven Rostedt <srostedt@xxxxxxxxxx>
AuthorDate: Tue, 24 Feb 2009 14:15:08 -0500
Commit: Steven Rostedt <srostedt@xxxxxxxxxx>
CommitDate: Tue, 24 Feb 2009 21:54:08 -0500
tracing: make event directory structure
This patch adds the directory /debug/tracing/events/ that will contain
all the registered trace points.
# ls /debug/tracing/events/
sched_kthread_stop sched_process_fork sched_switch
sched_kthread_stop_ret sched_process_free sched_wait_task
sched_migrate_task sched_process_wait sched_wakeup
sched_process_exit sched_signal_send sched_wakeup_new
# ls /debug/tracing/events/sched_switch/
enable
# cat /debug/tracing/events/sched_switch/enable
1
# cat /debug/tracing/set_event
sched_switch
Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx>
---
kernel/trace/trace_events.c | 137 +++++++++++++++++++++++++++++++++++++++++--
kernel/trace/trace_events.h | 7 ++-
2 files changed, 137 insertions(+), 7 deletions(-)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 05bc80e..3bcb9df 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -12,6 +12,11 @@
#include "trace_events.h"
+#define events_for_each(event) \
+ for (event = __start_ftrace_events; \
+ (unsigned long)event < (unsigned long)__stop_ftrace_events; \
+ event++)
+
void event_trace_printk(unsigned long ip, const char *fmt, ...)
{
va_list ap;
@@ -39,15 +44,16 @@ static void ftrace_clear_events(void)
static int ftrace_set_clr_event(char *buf, int set)
{
- struct ftrace_event_call *call = (void *)__start_ftrace_events;
+ struct ftrace_event_call *call = __start_ftrace_events;
- while ((unsigned long)call < (unsigned long)__stop_ftrace_events) {
+ events_for_each(call) {
- if (strcmp(buf, call->name) != 0) {
- call++;
+ if (!call->name)
+ continue;
+
+ if (strcmp(buf, call->name) != 0)
continue;
- }
if (set) {
/* Already set? */
@@ -223,6 +229,67 @@ ftrace_event_seq_open(struct inode *inode, struct file *file)
return ret;
}
+static ssize_t
+event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ char *buf;
+
+ if (call->enabled)
+ buf = "1\n";
+ else
+ buf = "0\n";
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+}
+
+static ssize_t
+event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ char buf[64];
+ unsigned long val;
+ int ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ switch (val) {
+ case 0:
+ if (!call->enabled)
+ break;
+
+ call->enabled = 0;
+ call->unregfunc();
+ break;
+ case 1:
+ if (call->enabled)
+ break;
+
+ call->enabled = 1;
+ call->regfunc();
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
static const struct seq_operations show_event_seq_ops = {
.start = t_start,
.next = t_next,
@@ -252,10 +319,59 @@ static const struct file_operations ftrace_set_event_fops = {
.release = seq_release,
};
+static const struct file_operations ftrace_enable_fops = {
+ .open = tracing_open_generic,
+ .read = event_enable_read,
+ .write = event_enable_write,
+};
+
+static struct dentry *event_trace_events_dir(void)
+{
+ static struct dentry *d_tracer;
+ static struct dentry *d_events;
+
+ if (d_events)
+ return d_events;
+
+ d_tracer = tracing_init_dentry();
+ if (!d_tracer)
+ return NULL;
+
+ d_events = debugfs_create_dir("events", d_tracer);
+ if (!d_events)
+ pr_warning("Could not create debugfs "
+ "'events' directory\n");
+
+ return d_events;
+}
+
+static int
+event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
+{
+ struct dentry *entry;
+
+ call->dir = debugfs_create_dir(call->name, d_events);
+ if (!call->dir) {
+ pr_warning("Could not create debugfs "
+ "'%s' directory\n", call->name);
+ return -1;
+ }
+
+ entry = debugfs_create_file("enable", 0644, call->dir, call,
+ &ftrace_enable_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'%s/enable' entry\n", call->name);
+
+ return 0;
+}
+
static __init int event_trace_init(void)
{
+ struct ftrace_event_call *call = __start_ftrace_events;
struct dentry *d_tracer;
struct dentry *entry;
+ struct dentry *d_events;
d_tracer = tracing_init_dentry();
if (!d_tracer)
@@ -275,6 +391,17 @@ static __init int event_trace_init(void)
pr_warning("Could not create debugfs "
"'set_event' entry\n");
+ d_events = event_trace_events_dir();
+ if (!d_events)
+ return 0;
+
+ events_for_each(call) {
+ /* The linker may leave blanks */
+ if (!call->name)
+ continue;
+ event_create_dir(call, d_events);
+ }
+
return 0;
}
fs_initcall(event_trace_init);
diff --git a/kernel/trace/trace_events.h b/kernel/trace/trace_events.h
index 39342f8..cb8455b 100644
--- a/kernel/trace/trace_events.h
+++ b/kernel/trace/trace_events.h
@@ -1,11 +1,13 @@
#ifndef _LINUX_KERNEL_TRACE_EVENTS_H
#define _LINUX_KERNEL_TRACE_EVENTS_H
+#include <linux/debugfs.h>
#include <linux/ftrace.h>
#include "trace.h"
struct ftrace_event_call {
char *name;
+ struct dentry *dir;
int enabled;
int (*regfunc)(void);
void (*unregfunc)(void);
@@ -39,6 +41,7 @@ static void ftrace_unreg_event_##call(void) \
} \
\
static struct ftrace_event_call __used \
+__attribute__((__aligned__(4))) \
__attribute__((section("_ftrace_events"))) event_##call = { \
.name = #call, \
.regfunc = ftrace_reg_event_##call, \
@@ -46,7 +49,7 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
}
void event_trace_printk(unsigned long ip, const char *fmt, ...);
-extern unsigned long __start_ftrace_events[];
-extern unsigned long __stop_ftrace_events[];
+extern struct ftrace_event_call __start_ftrace_events[];
+extern struct ftrace_event_call __stop_ftrace_events[];
#endif /* _LINUX_KERNEL_TRACE_EVENTS_H */
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|