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/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 7ed925e..c5d737c 100644 (file)
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -70,6 +70,8 @@ struct acpi_cpufreq_data {
 
 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
 
+DEFINE_TRACE(power_mark);
+
 /* acpi_perf_data is a pointer to percpu data. */
 static struct acpi_processor_performance *acpi_perf_data;
 

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 026819f..e0d0fd7 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -19,6 +19,9 @@ EXPORT_SYMBOL(idle_nomwait);
 
 struct kmem_cache *task_xstate_cachep;
 
+DEFINE_TRACE(power_start);
+DEFINE_TRACE(power_end);
+
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
        *dst = *src;

diff --git a/include/trace/power.h b/include/trace/power.h
index c7cefbc..2c733e5 100644 (file)
--- a/include/trace/power.h
+++ b/include/trace/power.h
@@ -2,6 +2,7 @@
 #define _TRACE_POWER_H
 
 #include <linux/ktime.h>
+#include <linux/tracepoint.h>
 
 enum {
        POWER_NONE = 0,
@@ -18,18 +19,16 @@ struct power_trace {
 #endif
 };
 
-#ifdef CONFIG_POWER_TRACER
-extern void trace_power_start(struct power_trace *it, unsigned int type,
-                                       unsigned int state);
-extern void trace_power_mark(struct power_trace *it, unsigned int type,
-                                       unsigned int state);
-extern void trace_power_end(struct power_trace *it);
-#else
-static inline void trace_power_start(struct power_trace *it, unsigned int type,
-                                       unsigned int state) { }
-static inline void trace_power_mark(struct power_trace *it, unsigned int type,
-                                       unsigned int state) { }
-static inline void trace_power_end(struct power_trace *it) { }
-#endif
+DECLARE_TRACE(power_start,
+       TPPROTO(struct power_trace *it, unsigned int type, unsigned int state),
+               TPARGS(it, type, state));
+
+DECLARE_TRACE(power_mark,
+       TPPROTO(struct power_trace *it, unsigned int type, unsigned int state),
+               TPARGS(it, type, state));
+
+DECLARE_TRACE(power_end,
+       TPPROTO(struct power_trace *it),
+               TPARGS(it));
 
 #endif /* _TRACE_POWER_H */

diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
index b1d0d08..91ce672 100644 (file)
--- 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 @@ static int power_trace_init(struct trace_array *tr)
        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 @@ static int init_power_trace(void)
        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);