Commit dd990352 authored by Daniel Bristot de Oliveira's avatar Daniel Bristot de Oliveira Committed by Steven Rostedt (Google)
Browse files

tracing/osnoise: Make osnoise_main to sleep for microseconds 

osnoise's runtime and period are in the microseconds scale, but it is
currently sleeping in the millisecond's scale. This behavior roots in the
usage of hwlat as the skeleton for osnoise.

Make osnoise to sleep in the microseconds scale. Also, move the sleep to
a specialized function.

Link: https://lkml.kernel.org/r/302aa6c7bdf2d131719b22901905e9da122a11b2.1645197336.git.bristot@kernel.org



Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: default avatarDaniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent ab2f993c

kernel/trace/trace_osnoise.c

+32 −21
Original line number Diff line number Diff line
@@ -1437,38 +1437,49 @@ static struct cpumask osnoise_cpumask; 
static struct cpumask save_cpumask;



/*

 * osnoise_main - The osnoise detection kernel thread

 *

 * Calls run_osnoise() function to measure the osnoise for the configured runtime,

 * every period.

 * osnoise_sleep - sleep until the next period

 */

static int osnoise_main(void *data)

static void osnoise_sleep(void)

{

	u64 interval;



	while (!kthread_should_stop()) {



		run_osnoise();

	ktime_t wake_time;



	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) {

	if (!interval) {

		/* Let synchronize_rcu_tasks() make progress */

		cond_resched_tasks_rcu_qs();

			continue;

		return;

	}



		if (msleep_interruptible(interval))

	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

 *

 * Calls run_osnoise() function to measure the osnoise for the configured runtime,

 * every period.

 */

static int osnoise_main(void *data)

{



	while (!kthread_should_stop()) {

		run_osnoise();

		osnoise_sleep();

	}



	return 0;

}