static struct cpumask osnoise_cpumask;
static struct cpumask save_cpumask;
+/*
+ * osnoise_sleep - sleep until the next period
+ */
+static void osnoise_sleep(void)
+{
+ u64 interval;
+ ktime_t wake_time;
+
+ mutex_lock(&interface_lock);
+ interval = osnoise_data.sample_period - osnoise_data.sample_runtime;
+ mutex_unlock(&interface_lock);
+
+ /*
+ * differently from hwlat_detector, the osnoise tracer can run
+ * without a pause because preemption is on.
+ */
+ if (!interval) {
+ /* Let synchronize_rcu_tasks() make progress */
+ cond_resched_tasks_rcu_qs();
+ return;
+ }
+
+ wake_time = ktime_add_us(ktime_get(), interval);
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ while (schedule_hrtimeout_range(&wake_time, 0, HRTIMER_MODE_ABS)) {
+ if (kthread_should_stop())
+ break;
+ }
+}
+
/*
* osnoise_main - The osnoise detection kernel thread
*
*/
static int osnoise_main(void *data)
{
- u64 interval;
while (!kthread_should_stop()) {
-
run_osnoise();
-
- mutex_lock(&interface_lock);
- interval = osnoise_data.sample_period - osnoise_data.sample_runtime;
- mutex_unlock(&interface_lock);
-
- do_div(interval, USEC_PER_MSEC);
-
- /*
- * differently from hwlat_detector, the osnoise tracer can run
- * without a pause because preemption is on.
- */
- if (interval < 1) {
- /* Let synchronize_rcu_tasks() make progress */
- cond_resched_tasks_rcu_qs();
- continue;
- }
-
- if (msleep_interruptible(interval))
- break;
+ osnoise_sleep();
}
return 0;
if (!top_dir)
return 0;
- tmp = tracefs_create_file("period_us", 0640, top_dir,
+ tmp = tracefs_create_file("period_us", TRACE_MODE_WRITE, top_dir,
&osnoise_period, &trace_min_max_fops);
if (!tmp)
goto err;
- tmp = tracefs_create_file("runtime_us", 0644, top_dir,
+ tmp = tracefs_create_file("runtime_us", TRACE_MODE_WRITE, top_dir,
&osnoise_runtime, &trace_min_max_fops);
if (!tmp)
goto err;
- tmp = tracefs_create_file("stop_tracing_us", 0640, top_dir,
+ tmp = tracefs_create_file("stop_tracing_us", TRACE_MODE_WRITE, top_dir,
&osnoise_stop_tracing_in, &trace_min_max_fops);
if (!tmp)
goto err;
- tmp = tracefs_create_file("stop_tracing_total_us", 0640, top_dir,
+ tmp = tracefs_create_file("stop_tracing_total_us", TRACE_MODE_WRITE, top_dir,
&osnoise_stop_tracing_total, &trace_min_max_fops);
if (!tmp)
goto err;
- tmp = trace_create_file("cpus", 0644, top_dir, NULL, &cpus_fops);
+ 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,
+ tmp = tracefs_create_file("print_stack", TRACE_MODE_WRITE, top_dir,
&osnoise_print_stack, &trace_min_max_fops);
if (!tmp)
goto err;
#endif
- tmp = tracefs_create_file("timerlat_period_us", 0640, top_dir,
+ tmp = tracefs_create_file("timerlat_period_us", TRACE_MODE_WRITE, top_dir,
&timerlat_period, &trace_min_max_fops);
if (!tmp)
goto err;
return -EINVAL;
}
+static void osnoise_unhook_events(void)
+{
+ unhook_thread_events();
+ unhook_softirq_events();
+ unhook_irq_events();
+}
+
static int __osnoise_tracer_start(struct trace_array *tr)
{
int retval;
retval = start_per_cpu_kthreads(tr);
if (retval) {
- unhook_irq_events();
+ trace_osnoise_callback_enabled = false;
+ /*
+ * Make sure that ftrace_nmi_enter/exit() see
+ * trace_osnoise_callback_enabled as false before continuing.
+ */
+ barrier();
+
+ osnoise_unhook_events();
return retval;
}
stop_per_cpu_kthreads();
- unhook_irq_events();
- unhook_softirq_events();
- unhook_thread_events();
+ osnoise_unhook_events();
osnoise_busy = false;
}