[PATCH 03/10] tracing: make the set_event and available_events subsystem aware

Steven Rostedt
2009-02-28T09:11:48Z

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From: Steven Rostedt <srostedt@redhat.com>

This patch makes the event files, set_event and available_events
aware of the subsystem.

Now you can enable an entire subsystem with:

echo 'irq:*' > set_event

Note: the '*' is not needed.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
kernel/trace/trace_events.c | 45 +++++++++++++++++++++++++++++++++++++++---
1 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 1933220..b811eb3 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -12,6 +12,8 @@

#include "trace_events.h"

+#define TRACE_SYSTEM "TRACE_SYSTEM"
+
#define events_for_each(event) \
for (event = __start_ftrace_events; \
(unsigned long)event < (unsigned long)__stop_ftrace_events; \
@@ -45,14 +47,47 @@ static void ftrace_clear_events(void)
static int ftrace_set_clr_event(char *buf, int set)
{
struct ftrace_event_call *call = __start_ftrace_events;
+ char *event = NULL, *sub = NULL, *match;
+ int ret = -EINVAL;
+
+ /*
+ * The buf format can be <subsystem>:<event-name>
+ * *:<event-name> means any event by that name.
+ * :<event-name> is the same.
+ *
+ * <subsystem>:* means all events in that subsystem
+ * <subsystem>: means the same.
+ *
+ * <name> (no ':') means all events in a subsystem with
+ * the name <name> or any event that matches <name>
+ */
+
+ match = strsep(&buf, ":");
+ if (buf) {
+ sub = match;
+ event = buf;
+ match = NULL;

+ if (!strlen(sub) || strcmp(sub, "*") == 0)
+ sub = NULL;
+ if (!strlen(event) || strcmp(event, "*") == 0)
+ event = NULL;
+ }

events_for_each(call) {

if (!call->name)
continue;

- if (strcmp(buf, call->name) != 0)
+ if (match &&
+ strcmp(match, call->name) != 0 &&
+ strcmp(match, call->system) != 0)
+ continue;
+
+ if (sub && strcmp(sub, call->system) != 0)
+ continue;
+
+ if (event && strcmp(event, call->name) != 0)
continue;

if (set) {
@@ -68,9 +103,9 @@ static int ftrace_set_clr_event(char *buf, int set)
call->enabled = 0;
call->unregfunc();
}
- return 0;
+ ret = 0;
}
- return -EINVAL;
+ return ret;
}

/* 128 should be much more than enough */
@@ -200,6 +235,8 @@ static int t_show(struct seq_file *m, void *v)
{
struct ftrace_event_call *call = v;

+ if (strcmp(call->system, TRACE_SYSTEM) != 0)
+ seq_printf(m, "%s:", call->system);
seq_printf(m, "%s\n", call->name);

return 0;
--
1.5.6.5

--