Commit 4fd5750a authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched,tracing: Convert to sched_set_fifo() 



One module user of sched_setscheduler() was overlooked and is
obviously causing build failures.

Convert ring_buffer_benchmark to use sched_set_fifo_low() when fifo==1
and sched_set_fifo() when fifo==2. This is a bit of an abuse, but it
makes the thing 'work' again.

Specifically, it enables all combinations that were previously
possible:

  producer higher than consumer
  consumer higher than producer

Fixes: 616d91b6 ("sched: Remove sched_setscheduler*() EXPORTs")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20200720214918.GM5523@worktop.programming.kicks-ass.net
parent 8b700983

kernel/trace/ring_buffer_benchmark.c

+23 −25
Original line number Diff line number Diff line
@@ -45,8 +45,8 @@ MODULE_PARM_DESC(write_iteration, "# of writes between timestamp readings"); 
static int producer_nice = MAX_NICE;

static int consumer_nice = MAX_NICE;



static int producer_fifo = -1;

static int consumer_fifo = -1;

static int producer_fifo;

static int consumer_fifo;



module_param(producer_nice, int, 0644);

MODULE_PARM_DESC(producer_nice, "nice prio for producer");
@@ -55,10 +55,10 @@ module_param(consumer_nice, int, 0644); 
MODULE_PARM_DESC(consumer_nice, "nice prio for consumer");



module_param(producer_fifo, int, 0644);

MODULE_PARM_DESC(producer_fifo, "fifo prio for producer");

MODULE_PARM_DESC(producer_fifo, "use fifo for producer: 0 - disabled, 1 - low prio, 2 - fifo");



module_param(consumer_fifo, int, 0644);

MODULE_PARM_DESC(consumer_fifo, "fifo prio for consumer");

MODULE_PARM_DESC(consumer_fifo, "use fifo for consumer: 0 - disabled, 1 - low prio, 2 - fifo");



static int read_events;
@@ -303,22 +303,22 @@ static void ring_buffer_producer(void) 
		trace_printk("ERROR!\n");



	if (!disable_reader) {

		if (consumer_fifo < 0)

		if (consumer_fifo)

			trace_printk("Running Consumer at SCHED_FIFO %s\n",

				     consumer_fifo == 1 ? "low" : "high");

		else

			trace_printk("Running Consumer at nice: %d\n",

				     consumer_nice);

		else

			trace_printk("Running Consumer at SCHED_FIFO %d\n",

				     consumer_fifo);

	}

	if (producer_fifo < 0)

	if (producer_fifo)

		trace_printk("Running Producer at SCHED_FIFO %s\n",

			     producer_fifo == 1 ? "low" : "high");

	else

		trace_printk("Running Producer at nice: %d\n",

			     producer_nice);

	else

		trace_printk("Running Producer at SCHED_FIFO %d\n",

			     producer_fifo);



	/* Let the user know that the test is running at low priority */

	if (producer_fifo < 0 && consumer_fifo < 0 &&

	if (!producer_fifo && !consumer_fifo &&

	    producer_nice == MAX_NICE && consumer_nice == MAX_NICE)

		trace_printk("WARNING!!! This test is running at lowest priority.\n");
@@ -455,21 +455,19 @@ static int __init ring_buffer_benchmark_init(void) 
	 * Run them as low-prio background tasks by default:

	 */

	if (!disable_reader) {

		if (consumer_fifo >= 0) {

			struct sched_param param = {

				.sched_priority = consumer_fifo

			};

			sched_setscheduler(consumer, SCHED_FIFO, &param);

		} else

		if (consumer_fifo >= 2)

			sched_set_fifo(consumer);

		else if (consumer_fifo == 1)

			sched_set_fifo_low(consumer);

		else

			set_user_nice(consumer, consumer_nice);

	}



	if (producer_fifo >= 0) {

		struct sched_param param = {

			.sched_priority = producer_fifo

		};

		sched_setscheduler(producer, SCHED_FIFO, &param);

	} else

	if (producer_fifo >= 2)

		sched_set_fifo(producer);

	else if (producer_fifo == 1)

		sched_set_fifo_low(producer);

	else

		set_user_nice(producer, producer_nice);



	return 0;

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