tracing/osnoise: Remove TIMERLAT ifdefs from inside functions

mainline inclusion
from mainline-v5.16-rc1
commit ccb67544
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4G64B
CVE: NA

-------------------------------------------------

Remove CONFIG_TIMERLAT_TRACER from inside functions, avoiding
compilation problems in the future.

Link: https://lkml.kernel.org/r/8245abb5a112d249f5da6c1df499244ad9e647bc.1635702894.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NDaniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

kernel/trace/trace_osnoise.c

@@ -321,6 +321,57 @@ static struct osnoise_data {
 #endif
 };
 
+#ifdef CONFIG_TIMERLAT_TRACER
+static inline bool timerlat_enabled(void)
+{
+	return osnoise_data.timerlat_tracer;
+}
+
+static inline int timerlat_softirq_exit(struct osnoise_variables *osn_var)
+{
+	struct timerlat_variables *tlat_var = this_cpu_tmr_var();
+	/*
+	 * If the timerlat is enabled, but the irq handler did
+	 * not run yet enabling timerlat_tracer, do not trace.
+	 */
+	if (!tlat_var->tracing_thread) {
+		osn_var->softirq.arrival_time = 0;
+		osn_var->softirq.delta_start = 0;
+		return 0;
+	}
+	return 1;
+}
+
+static inline int timerlat_thread_exit(struct osnoise_variables *osn_var)
+{
+	struct timerlat_variables *tlat_var = this_cpu_tmr_var();
+	/*
+	 * If the timerlat is enabled, but the irq handler did
+	 * not run yet enabling timerlat_tracer, do not trace.
+	 */
+	if (!tlat_var->tracing_thread) {
+		osn_var->thread.delta_start = 0;
+		osn_var->thread.arrival_time = 0;
+		return 0;
+	}
+	return 1;
+}
+#else /* CONFIG_TIMERLAT_TRACER */
+static inline bool timerlat_enabled(void)
+{
+	return false;
+}
+
+static inline int timerlat_softirq_exit(struct osnoise_variables *osn_var)
+{
+	return 1;
+}
+static inline int timerlat_thread_exit(struct osnoise_variables *osn_var)
+{
+	return 1;
+}
+#endif
+
 #ifdef CONFIG_PREEMPT_RT
 /*
  * Print the osnoise header info.
@@ -958,21 +1009,9 @@ static void trace_softirq_exit_callback(void *data, unsigned int vec_nr)
 	if (!osn_var->sampling)
 		return;
 
-#ifdef CONFIG_TIMERLAT_TRACER
-	/*
-	 * If the timerlat is enabled, but the irq handler did
-	 * not run yet enabling timerlat_tracer, do not trace.
-	 */
-	if (unlikely(osnoise_data.timerlat_tracer)) {
-		struct timerlat_variables *tlat_var;
-		tlat_var = this_cpu_tmr_var();
-		if (!tlat_var->tracing_thread) {
-			osn_var->softirq.arrival_time = 0;
-			osn_var->softirq.delta_start = 0;
+	if (unlikely(timerlat_enabled()))
+		if (!timerlat_softirq_exit(osn_var))
 			return;
-		}
-	}
-#endif
 
 	duration = get_int_safe_duration(osn_var, &osn_var->softirq.delta_start);
 	trace_softirq_noise(vec_nr, osn_var->softirq.arrival_time, duration);
@@ -1066,17 +1105,9 @@ thread_exit(struct osnoise_variables *osn_var, struct task_struct *t)
 	if (!osn_var->sampling)
 		return;
 
-#ifdef CONFIG_TIMERLAT_TRACER
-	if (osnoise_data.timerlat_tracer) {
-		struct timerlat_variables *tlat_var;
-		tlat_var = this_cpu_tmr_var();
-		if (!tlat_var->tracing_thread) {
-			osn_var->thread.delta_start = 0;
-			osn_var->thread.arrival_time = 0;
+	if (unlikely(timerlat_enabled()))
+		if (!timerlat_thread_exit(osn_var))
 			return;
-		}
-	}
-#endif
 
 	duration = get_int_safe_duration(osn_var, &osn_var->thread.delta_start);
 
@@ -1577,6 +1608,11 @@ static int timerlat_main(void *data)
 	hrtimer_cancel(&tlat->timer);
 	return 0;
 }
+#else /* CONFIG_TIMERLAT_TRACER */
+static int timerlat_main(void *data)
+{
+	return 0;
+}
 #endif /* CONFIG_TIMERLAT_TRACER */
 
 /*
@@ -1619,16 +1655,13 @@ static int start_kthread(unsigned int cpu)
 	void *main = osnoise_main;
 	char comm[24];
 
-#ifdef CONFIG_TIMERLAT_TRACER
-	if (osnoise_data.timerlat_tracer) {
+	if (timerlat_enabled()) {
 		snprintf(comm, 24, "timerlat/%d", cpu);
 		main = timerlat_main;
 	} else {
 		snprintf(comm, 24, "osnoise/%d", cpu);
 	}
-#else
-	snprintf(comm, 24, "osnoise/%d", cpu);
-#endif
+
 	kthread = kthread_create_on_cpu(main, NULL, cpu, comm);
 
 	if (IS_ERR(kthread)) {
@@ -1922,6 +1955,35 @@ static const struct file_operations cpus_fops = {
 	.llseek		= generic_file_llseek,
 };
 
+#ifdef CONFIG_TIMERLAT_TRACER
+/*
+ * init_timerlat_tracefs - A function to initialize the timerlat interface files
+ */
+static int init_timerlat_tracefs(struct dentry *top_dir)
+{
+	struct dentry *tmp;
+
+#ifdef CONFIG_STACKTRACE
+	tmp = tracefs_create_file("print_stack", TRACE_MODE_WRITE, top_dir,
+				  &osnoise_print_stack, &trace_min_max_fops);
+	if (!tmp)
+		return -ENOMEM;
+#endif
+
+	tmp = tracefs_create_file("timerlat_period_us", TRACE_MODE_WRITE, top_dir,
+				  &timerlat_period, &trace_min_max_fops);
+	if (!tmp)
+		return -ENOMEM;
+
+	return 0;
+}
+#else /* CONFIG_TIMERLAT_TRACER */
+static int init_timerlat_tracefs(struct dentry *top_dir)
+{
+	return 0;
+}
+#endif /* CONFIG_TIMERLAT_TRACER */
+
 /*
  * init_tracefs - A function to initialize the tracefs interface files
  *
@@ -1966,19 +2028,10 @@ static int init_tracefs(void)
 	tmp = trace_create_file("cpus", TRACE_MODE_WRITE, top_dir, NULL, &cpus_fops);
 	if (!tmp)
 		goto err;
-#ifdef CONFIG_TIMERLAT_TRACER
-#ifdef CONFIG_STACKTRACE
-	tmp = tracefs_create_file("print_stack", 0640, top_dir,
-				  &osnoise_print_stack, &trace_min_max_fops);
-	if (!tmp)
-		goto err;
-#endif
 
-	tmp = tracefs_create_file("timerlat_period_us", 0640, top_dir,
-				  &timerlat_period, &trace_min_max_fops);
-	if (!tmp)
+	ret = init_timerlat_tracefs(top_dir);
+	if (ret)
 		goto err;
-#endif
 
 	return 0;
 
@@ -2184,6 +2237,16 @@ static struct tracer timerlat_tracer __read_mostly = {
 	.print_header	= print_timerlat_headers,
 	.allow_instances = true,
 };
+
+__init static int init_timerlat_tracer(void)
+{
+	return register_tracer(&timerlat_tracer);
+}
+#else /* CONFIG_TIMERLAT_TRACER */
+__init static int init_timerlat_tracer(void)
+{
+	return 0;
+}
 #endif /* CONFIG_TIMERLAT_TRACER */
 
 __init static int init_osnoise_tracer(void)
@@ -2200,13 +2263,12 @@ __init static int init_osnoise_tracer(void)
 		return ret;
 	}
 
-#ifdef CONFIG_TIMERLAT_TRACER
-	ret = register_tracer(&timerlat_tracer);
+	ret = init_timerlat_tracer();
 	if (ret) {
-		pr_err(BANNER "Error registering timerlat\n");
+		pr_err(BANNER "Error registering timerlat!\n");
 		return ret;
 	}
-#endif
+
 	osnoise_init_hotplug_support();
 
 	INIT_LIST_HEAD_RCU(&osnoise_instances);