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, 5 insertions, 10 deletions

diff --git a/kernel/kthread.c b/kernel/kthread.c
index 31b072e8d427..99a3808d086f 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -593,18 +593,16 @@ EXPORT_SYMBOL(kthread_create_on_node);
 
 static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, unsigned int state)
 {
-	unsigned long flags;
-
 	if (!wait_task_inactive(p, state)) {
 		WARN_ON(1);
 		return;
 	}
 
+	scoped_guard (raw_spinlock_irqsave, &p->pi_lock)
+		set_cpus_allowed_force(p, mask);
+
 	/* It's safe because the task is inactive. */
-	raw_spin_lock_irqsave(&p->pi_lock, flags);
-	do_set_cpus_allowed(p, mask);
 	p->flags |= PF_NO_SETAFFINITY;
-	raw_spin_unlock_irqrestore(&p->pi_lock, flags);
 }
 
 static void __kthread_bind(struct task_struct *p, unsigned int cpu, unsigned int state)
@@ -857,7 +855,6 @@ int kthread_affine_preferred(struct task_struct *p, const struct cpumask *mask)
 {
 	struct kthread *kthread = to_kthread(p);
 	cpumask_var_t affinity;
-	unsigned long flags;
 	int ret = 0;
 
 	if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE) || kthread->started) {
@@ -882,10 +879,8 @@ int kthread_affine_preferred(struct task_struct *p, const struct cpumask *mask)
 	list_add_tail(&kthread->hotplug_node, &kthreads_hotplug);
 	kthread_fetch_affinity(kthread, affinity);
 
-	/* It's safe because the task is inactive. */
-	raw_spin_lock_irqsave(&p->pi_lock, flags);
-	do_set_cpus_allowed(p, affinity);
-	raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+	scoped_guard (raw_spinlock_irqsave, &p->pi_lock)
+		set_cpus_allowed_force(p, affinity);
 
 	mutex_unlock(&kthreads_hotplug_lock);
 out: