Merge tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull sched/fifo updates from Ingo Molnar:
 "This adds the sched_set_fifo*() encapsulation APIs to remove static
  priority level knowledge from non-scheduler code.

  The three APIs for non-scheduler code to set SCHED_FIFO are:

   - sched_set_fifo()
   - sched_set_fifo_low()
   - sched_set_normal()

  These are two FIFO priority levels: default (high), and a 'low'
  priority level, plus sched_set_normal() to set the policy back to
  non-SCHED_FIFO.

  Since the changes affect a lot of non-scheduler code, we kept this in
  a separate tree"

* tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  sched,tracing: Convert to sched_set_fifo()
  sched: Remove sched_set_*() return value
  sched: Remove sched_setscheduler*() EXPORTs
  sched,psi: Convert to sched_set_fifo_low()
  sched,rcutorture: Convert to sched_set_fifo_low()
  sched,rcuperf: Convert to sched_set_fifo_low()
  sched,locktorture: Convert to sched_set_fifo()
  sched,irq: Convert to sched_set_fifo()
  sched,watchdog: Convert to sched_set_fifo()
  sched,serial: Convert to sched_set_fifo()
  sched,powerclamp: Convert to sched_set_fifo()
  sched,ion: Convert to sched_set_normal()
  sched,powercap: Convert to sched_set_fifo*()
  sched,spi: Convert to sched_set_fifo*()
  sched,mmc: Convert to sched_set_fifo*()
  sched,ivtv: Convert to sched_set_fifo*()
  sched,drm/scheduler: Convert to sched_set_fifo*()
  sched,msm: Convert to sched_set_fifo*()
  sched,psci: Convert to sched_set_fifo*()
  sched,drbd: Convert to sched_set_fifo*()
  ...

3 files changed, 4 insertions, 18 deletions

diff --git a/drivers/gpu/drm/drm_vblank_work.c b/drivers/gpu/drm/drm_vblank_work.c
index 7ac0fc0a9415..bd481fdd6b87 100644
--- a/drivers/gpu/drm/drm_vblank_work.c
+++ b/drivers/gpu/drm/drm_vblank_work.c
@@ -248,9 +248,6 @@ EXPORT_SYMBOL(drm_vblank_work_init);
 
 int drm_vblank_worker_init(struct drm_vblank_crtc *vblank)
 {
-	struct sched_param param = {
-		.sched_priority = MAX_RT_PRIO - 1,
-	};
 	struct kthread_worker *worker;
 
 	INIT_LIST_HEAD(&vblank->pending_work);
@@ -263,5 +260,6 @@ int drm_vblank_worker_init(struct drm_vblank_crtc *vblank)
 
 	vblank->worker = worker;
 
-	return sched_setscheduler(vblank->worker->task, SCHED_FIFO, &param);
+	sched_set_fifo(worker->task);
+	return 0;
 }
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 36d98d4116ca..7d641c7e3514 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -401,7 +401,6 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 	struct msm_kms *kms;
 	struct msm_mdss *mdss;
 	int ret, i;
-	struct sched_param param;
 
 	ddev = drm_dev_alloc(drv, dev);
 	if (IS_ERR(ddev)) {
@@ -507,12 +506,6 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 	ddev->mode_config.funcs = &mode_config_funcs;
 	ddev->mode_config.helper_private = &mode_config_helper_funcs;
 
-	/**
-	 * this priority was found during empiric testing to have appropriate
-	 * realtime scheduling to process display updates and interact with
-	 * other real time and normal priority task
-	 */
-	param.sched_priority = 16;
 	for (i = 0; i < priv->num_crtcs; i++) {
 		/* initialize event thread */
 		priv->event_thread[i].crtc_id = priv->crtcs[i]->base.id;
@@ -524,11 +517,7 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 			goto err_msm_uninit;
 		}
 
-		ret = sched_setscheduler(priv->event_thread[i].worker->task,
-					 SCHED_FIFO, &param);
-		if (ret)
-			dev_warn(dev, "event_thread set priority failed:%d\n",
-				 ret);
+		sched_set_fifo(priv->event_thread[i].worker->task);
 	}
 
 	ret = drm_vblank_init(ddev, priv->num_crtcs);
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index d6eaa23ad746..96f763d888af 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -762,11 +762,10 @@ static bool drm_sched_blocked(struct drm_gpu_scheduler *sched)
  */
 static int drm_sched_main(void *param)
 {
-	struct sched_param sparam = {.sched_priority = 1};
 	struct drm_gpu_scheduler *sched = (struct drm_gpu_scheduler *)param;
 	int r;
 
-	sched_setscheduler(current, SCHED_FIFO, &sparam);
+	sched_set_fifo_low(current);
 
 	while (!kthread_should_stop()) {
 		struct drm_sched_entity *entity = NULL;