tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints
Register/unregister tracepoint probes with struct tracepoint pointer
rather than tracepoint name.
This change, which vastly simplifies tracepoint.c, has been proposed by
Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux
size.
From this point on, the tracers need to pass a struct tracepoint pointer
to probe register/unregister. A probe can now only be connected to a
tracepoint that exists. Moreover, tracers are responsible for
unregistering the probe before the module containing its associated
tracepoint is unloaded.
text data bss dec hex filename
10443444 4282528 10391552 25117524 17f4354 vmlinux.orig
10434930 4282848 10391552 25109330 17f2352 vmlinux
Link: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com
CC: Ingo Molnar <mingo@kernel.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Frank Ch. Eigler <fche@redhat.com>
CC: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
[ SDR - fixed return val in void func in tracepoint_module_going() ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 83a4378..3ddfd8f 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -223,24 +223,25 @@
{
struct ftrace_event_file *file = data;
+ WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
switch (type) {
case TRACE_REG_REGISTER:
- return tracepoint_probe_register(call->name,
+ return tracepoint_probe_register(call->tp,
call->class->probe,
file);
case TRACE_REG_UNREGISTER:
- tracepoint_probe_unregister(call->name,
+ tracepoint_probe_unregister(call->tp,
call->class->probe,
file);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
- return tracepoint_probe_register(call->name,
+ return tracepoint_probe_register(call->tp,
call->class->perf_probe,
call);
case TRACE_REG_PERF_UNREGISTER:
- tracepoint_probe_unregister(call->name,
+ tracepoint_probe_unregister(call->tp,
call->class->perf_probe,
call);
return 0;
@@ -352,7 +353,7 @@
if (ret) {
tracing_stop_cmdline_record();
pr_info("event trace: Could not enable event "
- "%s\n", call->name);
+ "%s\n", ftrace_event_name(call));
break;
}
set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
@@ -481,27 +482,29 @@
{
struct ftrace_event_file *file;
struct ftrace_event_call *call;
+ const char *name;
int ret = -EINVAL;
list_for_each_entry(file, &tr->events, list) {
call = file->event_call;
+ name = ftrace_event_name(call);
- if (!call->name || !call->class || !call->class->reg)
+ if (!name || !call->class || !call->class->reg)
continue;
if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
continue;
if (match &&
- strcmp(match, call->name) != 0 &&
+ strcmp(match, name) != 0 &&
strcmp(match, call->class->system) != 0)
continue;
if (sub && strcmp(sub, call->class->system) != 0)
continue;
- if (event && strcmp(event, call->name) != 0)
+ if (event && strcmp(event, name) != 0)
continue;
ftrace_event_enable_disable(file, set);
@@ -699,7 +702,7 @@
if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
seq_printf(m, "%s:", call->class->system);
- seq_printf(m, "%s\n", call->name);
+ seq_printf(m, "%s\n", ftrace_event_name(call));
return 0;
}
@@ -792,7 +795,7 @@
mutex_lock(&event_mutex);
list_for_each_entry(file, &tr->events, list) {
call = file->event_call;
- if (!call->name || !call->class || !call->class->reg)
+ if (!ftrace_event_name(call) || !call->class || !call->class->reg)
continue;
if (system && strcmp(call->class->system, system->name) != 0)
@@ -907,7 +910,7 @@
switch ((unsigned long)v) {
case FORMAT_HEADER:
- seq_printf(m, "name: %s\n", call->name);
+ seq_printf(m, "name: %s\n", ftrace_event_name(call));
seq_printf(m, "ID: %d\n", call->event.type);
seq_printf(m, "format:\n");
return 0;
@@ -1527,6 +1530,7 @@
struct trace_array *tr = file->tr;
struct list_head *head;
struct dentry *d_events;
+ const char *name;
int ret;
/*
@@ -1540,10 +1544,11 @@
} else
d_events = parent;
- file->dir = debugfs_create_dir(call->name, d_events);
+ name = ftrace_event_name(call);
+ file->dir = debugfs_create_dir(name, d_events);
if (!file->dir) {
pr_warning("Could not create debugfs '%s' directory\n",
- call->name);
+ name);
return -1;
}
@@ -1567,7 +1572,7 @@
ret = call->class->define_fields(call);
if (ret < 0) {
pr_warning("Could not initialize trace point"
- " events/%s\n", call->name);
+ " events/%s\n", name);
return -1;
}
}
@@ -1631,15 +1636,17 @@
static int event_init(struct ftrace_event_call *call)
{
int ret = 0;
+ const char *name;
- if (WARN_ON(!call->name))
+ name = ftrace_event_name(call);
+ if (WARN_ON(!name))
return -EINVAL;
if (call->class->raw_init) {
ret = call->class->raw_init(call);
if (ret < 0 && ret != -ENOSYS)
pr_warn("Could not initialize trace events/%s\n",
- call->name);
+ name);
}
return ret;
@@ -1885,7 +1892,7 @@
ret = __trace_add_new_event(call, tr);
if (ret < 0)
pr_warning("Could not create directory for event %s\n",
- call->name);
+ ftrace_event_name(call));
}
}
@@ -1894,18 +1901,20 @@
{
struct ftrace_event_file *file;
struct ftrace_event_call *call;
+ const char *name;
list_for_each_entry(file, &tr->events, list) {
call = file->event_call;
+ name = ftrace_event_name(call);
- if (!call->name || !call->class || !call->class->reg)
+ if (!name || !call->class || !call->class->reg)
continue;
if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
continue;
- if (strcmp(event, call->name) == 0 &&
+ if (strcmp(event, name) == 0 &&
strcmp(system, call->class->system) == 0)
return file;
}
@@ -1973,7 +1982,7 @@
seq_printf(m, "%s:%s:%s",
data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
data->file->event_call->class->system,
- data->file->event_call->name);
+ ftrace_event_name(data->file->event_call));
if (data->count == -1)
seq_printf(m, ":unlimited\n");
@@ -2193,7 +2202,7 @@
ret = event_create_dir(tr->event_dir, file);
if (ret < 0)
pr_warning("Could not create directory for event %s\n",
- file->event_call->name);
+ ftrace_event_name(file->event_call));
}
}
@@ -2217,7 +2226,7 @@
ret = __trace_early_add_new_event(call, tr);
if (ret < 0)
pr_warning("Could not create early event %s\n",
- call->name);
+ ftrace_event_name(call));
}
}
@@ -2549,7 +2558,7 @@
continue;
#endif
- pr_info("Testing event %s: ", call->name);
+ pr_info("Testing event %s: ", ftrace_event_name(call));
/*
* If an event is already enabled, someone is using