tracing: convert c/p state power tracer to use tracepoints
Convert the c/p state "power" tracer to use tracepoints. Avoids a
function call when the tracer is disabled.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
index b1d0d08..91ce672 100644
--- a/kernel/trace/trace_power.c
+++ b/kernel/trace/trace_power.c
@@ -21,15 +21,116 @@
static struct trace_array *power_trace;
static int __read_mostly trace_power_enabled;
+static void probe_power_start(struct power_trace *it, unsigned int type,
+ unsigned int level)
+{
+ if (!trace_power_enabled)
+ return;
+
+ memset(it, 0, sizeof(struct power_trace));
+ it->state = level;
+ it->type = type;
+ it->stamp = ktime_get();
+}
+
+
+static void probe_power_end(struct power_trace *it)
+{
+ struct ring_buffer_event *event;
+ struct trace_power *entry;
+ struct trace_array_cpu *data;
+ struct trace_array *tr = power_trace;
+
+ if (!trace_power_enabled)
+ return;
+
+ preempt_disable();
+ it->end = ktime_get();
+ data = tr->data[smp_processor_id()];
+
+ event = trace_buffer_lock_reserve(tr, TRACE_POWER,
+ sizeof(*entry), 0, 0);
+ if (!event)
+ goto out;
+ entry = ring_buffer_event_data(event);
+ entry->state_data = *it;
+ trace_buffer_unlock_commit(tr, event, 0, 0);
+ out:
+ preempt_enable();
+}
+
+static void probe_power_mark(struct power_trace *it, unsigned int type,
+ unsigned int level)
+{
+ struct ring_buffer_event *event;
+ struct trace_power *entry;
+ struct trace_array_cpu *data;
+ struct trace_array *tr = power_trace;
+
+ if (!trace_power_enabled)
+ return;
+
+ memset(it, 0, sizeof(struct power_trace));
+ it->state = level;
+ it->type = type;
+ it->stamp = ktime_get();
+ preempt_disable();
+ it->end = it->stamp;
+ data = tr->data[smp_processor_id()];
+
+ event = trace_buffer_lock_reserve(tr, TRACE_POWER,
+ sizeof(*entry), 0, 0);
+ if (!event)
+ goto out;
+ entry = ring_buffer_event_data(event);
+ entry->state_data = *it;
+ trace_buffer_unlock_commit(tr, event, 0, 0);
+ out:
+ preempt_enable();
+}
+
+static int tracing_power_register(void)
+{
+ int ret;
+
+ ret = register_trace_power_start(probe_power_start);
+ if (ret) {
+ pr_info("power trace: Couldn't activate tracepoint"
+ " probe to trace_power_start\n");
+ return ret;
+ }
+ ret = register_trace_power_end(probe_power_end);
+ if (ret) {
+ pr_info("power trace: Couldn't activate tracepoint"
+ " probe to trace_power_end\n");
+ goto fail_start;
+ }
+ ret = register_trace_power_mark(probe_power_mark);
+ if (ret) {
+ pr_info("power trace: Couldn't activate tracepoint"
+ " probe to trace_power_mark\n");
+ goto fail_end;
+ }
+ return ret;
+fail_end:
+ unregister_trace_power_end(probe_power_end);
+fail_start:
+ unregister_trace_power_start(probe_power_start);
+ return ret;
+}
static void start_power_trace(struct trace_array *tr)
{
trace_power_enabled = 1;
+ tracing_power_register();
}
static void stop_power_trace(struct trace_array *tr)
{
trace_power_enabled = 0;
+ unregister_trace_power_start(probe_power_start);
+ unregister_trace_power_end(probe_power_end);
+ unregister_trace_power_mark(probe_power_mark);
}
@@ -39,6 +140,7 @@
power_trace = tr;
trace_power_enabled = 1;
+ tracing_power_register();
for_each_cpu(cpu, cpu_possible_mask)
tracing_reset(tr, cpu);
@@ -95,74 +197,3 @@
return register_tracer(&power_tracer);
}
device_initcall(init_power_trace);
-
-void trace_power_start(struct power_trace *it, unsigned int type,
- unsigned int level)
-{
- if (!trace_power_enabled)
- return;
-
- memset(it, 0, sizeof(struct power_trace));
- it->state = level;
- it->type = type;
- it->stamp = ktime_get();
-}
-EXPORT_SYMBOL_GPL(trace_power_start);
-
-
-void trace_power_end(struct power_trace *it)
-{
- struct ring_buffer_event *event;
- struct trace_power *entry;
- struct trace_array_cpu *data;
- struct trace_array *tr = power_trace;
-
- if (!trace_power_enabled)
- return;
-
- preempt_disable();
- it->end = ktime_get();
- data = tr->data[smp_processor_id()];
-
- event = trace_buffer_lock_reserve(tr, TRACE_POWER,
- sizeof(*entry), 0, 0);
- if (!event)
- goto out;
- entry = ring_buffer_event_data(event);
- entry->state_data = *it;
- trace_buffer_unlock_commit(tr, event, 0, 0);
- out:
- preempt_enable();
-}
-EXPORT_SYMBOL_GPL(trace_power_end);
-
-void trace_power_mark(struct power_trace *it, unsigned int type,
- unsigned int level)
-{
- struct ring_buffer_event *event;
- struct trace_power *entry;
- struct trace_array_cpu *data;
- struct trace_array *tr = power_trace;
-
- if (!trace_power_enabled)
- return;
-
- memset(it, 0, sizeof(struct power_trace));
- it->state = level;
- it->type = type;
- it->stamp = ktime_get();
- preempt_disable();
- it->end = it->stamp;
- data = tr->data[smp_processor_id()];
-
- event = trace_buffer_lock_reserve(tr, TRACE_POWER,
- sizeof(*entry), 0, 0);
- if (!event)
- goto out;
- entry = ring_buffer_event_data(event);
- entry->state_data = *it;
- trace_buffer_unlock_commit(tr, event, 0, 0);
- out:
- preempt_enable();
-}
-EXPORT_SYMBOL_GPL(trace_power_mark);