Merge tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Core & fair scheduler changes:

   - Cancel the slice protection of the idle entity (Zihan Zhou)
   - Reduce the default slice to avoid tasks getting an extra tick
     (Zihan Zhou)
   - Force propagating min_slice of cfs_rq when {en,de}queue tasks
     (Tianchen Ding)
   - Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
   - Add unlikey branch hints to several system calls (Colin Ian King)
   - Optimize current_clr_polling() on certain architectures (Yujun
     Dong)

  Deadline scheduler: (Juri Lelli)
   - Remove redundant dl_clear_root_domain call
   - Move dl_rebuild_rd_accounting to cpuset.h

  Uclamp:
   - Use the uclamp_is_used() helper instead of open-coding it (Xuewen
     Yan)
   - Optimize sched_uclamp_used static key enabling (Xuewen Yan)

  Scheduler topology support: (Juri Lelli)
   - Ignore special tasks when rebuilding domains
   - Add wrappers for sched_domains_mutex
   - Generalize unique visiting of root domains
   - Rebuild root domain accounting after every update
   - Remove partition_and_rebuild_sched_domains
   - Stop exposing partition_sched_domains_locked

  RSEQ: (Michael Jeanson)
   - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
   - Fix segfault on registration when rseq_cs is non-zero
   - selftests: Add rseq syscall errors test
   - selftests: Ensure the rseq ABI TLS is actually 1024 bytes

  Membarriers:
   - Fix redundant load of membarrier_state (Nysal Jan K.A.)

  Scheduler debugging:
   - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
   - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)

  Fixes and cleanups:
   - Always save/restore x86 TSC sched_clock() on suspend/resume
     (Guilherme G. Piccoli)
   - Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian
     Andrzej Siewior)"

* tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling()
  sched/debug: Remove CONFIG_SCHED_DEBUG
  sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files
  sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation
  sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional
  sched/debug: Make 'const_debug' tunables unconditional __read_mostly
  sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()
  rseq/selftests: Fix namespace collision with rseq UAPI header
  include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h
  sched/topology: Stop exposing partition_sched_domains_locked
  cgroup/cpuset: Remove partition_and_rebuild_sched_domains
  sched/topology: Remove redundant dl_clear_root_domain call
  sched/deadline: Rebuild root domain accounting after every update
  sched/deadline: Generalize unique visiting of root domains
  sched/topology: Wrappers for sched_domains_mutex
  sched/deadline: Ignore special tasks when rebuilding domains
  tracing: Use preempt_model_str()
  xtensa: Rely on generic printing of preemption model
  x86: Rely on generic printing of preemption model
  s390: Rely on generic printing of preemption model
  ...

1 files changed, 17 insertions, 17 deletions

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 5a637292faa2..39c1fc643d77 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -953,10 +953,12 @@ static void dl_update_tasks_root_domain(struct cpuset *cs)
 	css_task_iter_end(&it);
 }
 
-static void dl_rebuild_rd_accounting(void)
+void dl_rebuild_rd_accounting(void)
 {
 	struct cpuset *cs = NULL;
 	struct cgroup_subsys_state *pos_css;
+	int cpu;
+	u64 cookie = ++dl_cookie;
 
 	lockdep_assert_held(&cpuset_mutex);
 	lockdep_assert_cpus_held();
@@ -964,11 +966,12 @@ static void dl_rebuild_rd_accounting(void)
 
 	rcu_read_lock();
 
-	/*
-	 * Clear default root domain DL accounting, it will be computed again
-	 * if a task belongs to it.
-	 */
-	dl_clear_root_domain(&def_root_domain);
+	for_each_possible_cpu(cpu) {
+		if (dl_bw_visited(cpu, cookie))
+			continue;
+
+		dl_clear_root_domain_cpu(cpu);
+	}
 
 	cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) {
 
@@ -989,16 +992,6 @@ static void dl_rebuild_rd_accounting(void)
 	rcu_read_unlock();
 }
 
-static void
-partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
-				    struct sched_domain_attr *dattr_new)
-{
-	mutex_lock(&sched_domains_mutex);
-	partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
-	dl_rebuild_rd_accounting();
-	mutex_unlock(&sched_domains_mutex);
-}
-
 /*
  * Rebuild scheduler domains.
  *
@@ -1060,7 +1053,7 @@ void rebuild_sched_domains_locked(void)
 	ndoms = generate_sched_domains(&doms, &attr);
 
 	/* Have scheduler rebuild the domains */
-	partition_and_rebuild_sched_domains(ndoms, doms, attr);
+	partition_sched_domains(ndoms, doms, attr);
 }
 #else /* !CONFIG_SMP */
 void rebuild_sched_domains_locked(void)
@@ -1082,6 +1075,13 @@ void rebuild_sched_domains(void)
 	cpus_read_unlock();
 }
 
+void cpuset_reset_sched_domains(void)
+{
+	mutex_lock(&cpuset_mutex);
+	partition_sched_domains(1, NULL, NULL);
+	mutex_unlock(&cpuset_mutex);
+}
+
 /**
  * cpuset_update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
  * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed