linux-kernel - [PATCH 07/23] sched,msm: Convert to sched_set

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Message-Id: <20200422112831.633583714@infradead.org>
Date:   Wed, 22 Apr 2020 13:27:26 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     mingo@...nel.org, linux-kernel@...r.kernel.org
Cc:     tglx@...utronix.de, rostedt@...dmis.org, qais.yousef@....com,
        juri.lelli@...hat.com, vincent.guittot@...aro.org,
        dietmar.eggemann@....com, bsegall@...gle.com, mgorman@...e.de,
        peterz@...radead.org, airlied@...hat.com
Subject: [PATCH 07/23] sched,msm: Convert to sched_set_fifo*()

Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.

Use sched_set_fifo(); Effectively changes prio from 16 to 50.

Cc: airlied@...hat.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Reviewed-by: Ingo Molnar <mingo@...nel.org>
---
 drivers/gpu/drm/msm/msm_drv.c |   10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -388,7 +388,6 @@ static int msm_drm_init(struct device *d
 	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)) {
@@ -494,12 +493,6 @@ static int msm_drm_init(struct device *d
 	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;
@@ -515,8 +508,7 @@ static int msm_drm_init(struct device *d
 			goto err_msm_uninit;
 		}
 
-		ret = sched_setscheduler(priv->event_thread[i].thread,
-					 SCHED_FIFO, &param);
+		ret = sched_set_fifo(priv->event_thread[i].thread);
 		if (ret)
 			dev_warn(dev, "event_thread set priority failed:%d\n",
 				 ret);