From 0754d5caac719f649dbb73365741dcb90fbf793a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 15 Jan 2026 09:25:37 +0100 Subject: [PATCH] sched: Deadline has dynamic priority [ Upstream commit e008ec6c7904ed99d3b2cb634b6545b008a99288 ] While FIFO/RR have static priority, DEADLINE is a dynamic priority scheme. Notably it has static priority -1. Do not assume the priority doesn't change for deadline tasks just because the static priority doesn't change. This ensures DL always sees {DE,EN}QUEUE_MOVE where appropriate. Fixes: ff77e4685359 ("sched/rt: Fix PI handling vs. sched_setscheduler()") Signed-off-by: Peter Zijlstra (Intel) Tested-by: Pierre Gondois Tested-by: Juri Lelli Link: https://patch.msgid.link/20260114130528.GB831285@noisy.programming.kicks-ass.net Signed-off-by: Sasha Levin --- kernel/sched/core.c | 2 +- kernel/sched/syscalls.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index eb47d294e2c5..e460c22de8ad 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7383,7 +7383,7 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) trace_sched_pi_setprio(p, pi_task); oldprio = p->prio; - if (oldprio == prio) + if (oldprio == prio && !dl_prio(prio)) queue_flag &= ~DEQUEUE_MOVE; prev_class = p->sched_class; diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c index bf360a6fbb80..6805a63d47af 100644 --- a/kernel/sched/syscalls.c +++ b/kernel/sched/syscalls.c @@ -688,7 +688,7 @@ change: * itself. */ newprio = rt_effective_prio(p, newprio); - if (newprio == oldprio) + if (newprio == oldprio && !dl_prio(newprio)) queue_flags &= ~DEQUEUE_MOVE; }