Merge tag 'sched-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Scalability and load-balancing improvements:

   - Enable scheduler feature NEXT_BUDDY (Mel Gorman)

   - Reimplement NEXT_BUDDY to align with EEVDF goals (Mel Gorman)

   - Skip sched_balance_running cmpxchg when balance is not due (Tim
     Chen)

   - Implement generic code for architecture specific sched domain NUMA
     distances (Tim Chen)

   - Optimize the NUMA distances of the sched-domains builds of Intel
     Granite Rapids (GNR) and Clearwater Forest (CWF) platforms (Tim
     Chen)

   - Implement proportional newidle balance: a randomized algorithm that
     runs newidle balancing proportional to its success rate. (Peter
     Zijlstra)

  Scheduler infrastructure changes:

   - Implement the 'sched_change' scoped_guard() pattern for the entire
     scheduler (Peter Zijlstra)

   - More broadly utilize the sched_change guard (Peter Zijlstra)

   - Add support to pick functions to take runqueue-flags (Joel
     Fernandes)

   - Provide and use set_need_resched_current() (Peter Zijlstra)

  Fair scheduling enhancements:

   - Forfeit vruntime on yield (Fernand Sieber)

   - Only update stats for allowed CPUs when looking for dst group (Adam
     Li)

  CPU-core scheduling enhancements:

   - Optimize core cookie matching check (Fernand Sieber)

  Deadline scheduler fixes:

   - Only set free_cpus for online runqueues (Doug Berger)

   - Fix dl_server time accounting (Peter Zijlstra)

   - Fix dl_server stop condition (Peter Zijlstra)

  Proxy scheduling fixes:

   - Yield the donor task (Fernand Sieber)

  Fixes and cleanups:

   - Fix do_set_cpus_allowed() locking (Peter Zijlstra)

   - Fix migrate_disable_switch() locking (Peter Zijlstra)

   - Remove double update_rq_clock() in __set_cpus_allowed_ptr_locked()
     (Hao Jia)

   - Increase sched_tick_remote timeout (Phil Auld)

   - sched/deadline: Use cpumask_weight_and() in dl_bw_cpus() (Shrikanth
     Hegde)

   - sched/deadline: Clean up select_task_rq_dl() (Shrikanth Hegde)"

* tag 'sched-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  sched: Provide and use set_need_resched_current()
  sched/fair: Proportional newidle balance
  sched/fair: Small cleanup to update_newidle_cost()
  sched/fair: Small cleanup to sched_balance_newidle()
  sched/fair: Revert max_newidle_lb_cost bump
  sched/fair: Reimplement NEXT_BUDDY to align with EEVDF goals
  sched/fair: Enable scheduler feature NEXT_BUDDY
  sched: Increase sched_tick_remote timeout
  sched/fair: Have SD_SERIALIZE affect newidle balancing
  sched/fair: Skip sched_balance_running cmpxchg when balance is not due
  sched/deadline: Minor cleanup in select_task_rq_dl()
  sched/deadline: Use cpumask_weight_and() in dl_bw_cpus
  sched/deadline: Document dl_server
  sched/deadline: Fix dl_server stop condition
  sched/deadline: Fix dl_server time accounting
  sched/core: Remove double update_rq_clock() in __set_cpus_allowed_ptr_locked()
  sched/eevdf: Fix min_vruntime vs avg_vruntime
  sched/core: Add comment explaining force-idle vruntime snapshots
  sched/core: Optimize core cookie matching check
  sched/proxy: Yield the donor task
  ...

1 files changed, 9 insertions, 4 deletions

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 7936d4333731..f1867fe8e5c5 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1490,7 +1490,7 @@ static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
 
 static void yield_task_rt(struct rq *rq)
 {
-	requeue_task_rt(rq, rq->curr, 0);
+	requeue_task_rt(rq, rq->donor, 0);
 }
 
 static int find_lowest_rq(struct task_struct *task);
@@ -1695,7 +1695,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq)
 	return rt_task_of(rt_se);
 }
 
-static struct task_struct *pick_task_rt(struct rq *rq)
+static struct task_struct *pick_task_rt(struct rq *rq, struct rq_flags *rf)
 {
 	struct task_struct *p;
 
@@ -2437,11 +2437,14 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
  * us to initiate a push or pull.
  */
 static void
-prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
+prio_changed_rt(struct rq *rq, struct task_struct *p, u64 oldprio)
 {
 	if (!task_on_rq_queued(p))
 		return;
 
+	if (p->prio == oldprio)
+		return;
+
 	if (task_current_donor(rq, p)) {
 		/*
 		 * If our priority decreases while running, we
@@ -2566,6 +2569,8 @@ static int task_is_throttled_rt(struct task_struct *p, int cpu)
 
 DEFINE_SCHED_CLASS(rt) = {
 
+	.queue_mask		= 4,
+
 	.enqueue_task		= enqueue_task_rt,
 	.dequeue_task		= dequeue_task_rt,
 	.yield_task		= yield_task_rt,
@@ -2589,8 +2594,8 @@ DEFINE_SCHED_CLASS(rt) = {
 
 	.get_rr_interval	= get_rr_interval_rt,
 
-	.prio_changed		= prio_changed_rt,
 	.switched_to		= switched_to_rt,
+	.prio_changed		= prio_changed_rt,
 
 	.update_curr		= update_curr_rt,