Merge branch '6.11/prjc' into 6.11/main

Add changes from Project-C 6.12:
 - sched/alt: Simpifly migrate_enable/disable design.

include/linux/sched.h

@@ -874,11 +874,15 @@ struct task_struct {
 	const cpumask_t			*cpus_ptr;
 	cpumask_t			*user_cpus_ptr;
 	cpumask_t			cpus_mask;
+#ifndef CONFIG_SCHED_ALT
 	void				*migration_pending;
+#endif
 #ifdef CONFIG_SMP
 	unsigned short			migration_disabled;
 #endif
+#ifndef CONFIG_SCHED_ALT
 	unsigned short			migration_flags;
+#endif
 
 #ifdef CONFIG_PREEMPT_RCU
 	int				rcu_read_lock_nesting;

kernel/sched/alt_core.c

@@ -1438,8 +1438,6 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 	__set_task_cpu(p, new_cpu);
 }
 
-#define MDF_FORCE_ENABLED	0x80
-
 static void
 __do_set_cpus_ptr(struct task_struct *p, const struct cpumask *new_mask)
 {
@@ -1474,8 +1472,6 @@ void migrate_disable(void)
 	if (cpumask_test_cpu(cpu, &p->cpus_mask)) {
 		cpu_rq(cpu)->nr_pinned++;
 		p->migration_disabled = 1;
-		p->migration_flags &= ~MDF_FORCE_ENABLED;
-
 		/*
 		 * Violates locking rules! see comment in __do_set_cpus_ptr().
 		 */
@@ -1505,10 +1501,6 @@ void migrate_enable(void)
 	 * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule().
 	 */
 	guard(preempt)();
-	/*
-	 * Assumption: current should be running on allowed cpu
-	 */
-	WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &p->cpus_mask));
 	if (p->cpus_ptr != &p->cpus_mask)
 		__do_set_cpus_ptr(p, &p->cpus_mask);
 	/*
@@ -2004,7 +1996,6 @@ static int affine_move_task(struct rq *rq, struct task_struct *p, int dest_cpu,
 			if (likely(p->cpus_ptr != &p->cpus_mask))
 				__do_set_cpus_ptr(p, &p->cpus_mask);
 			p->migration_disabled = 0;
-			p->migration_flags |= MDF_FORCE_ENABLED;
 			/* When p is migrate_disabled, rq->lock should be held */
 			rq->nr_pinned--;
 		}
@@ -6461,9 +6452,6 @@ void __cant_migrate(const char *file, int line)
 	if (preempt_count() > 0)
 		return;
 
-	if (current->migration_flags & MDF_FORCE_ENABLED)
-		return;
-
 	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
 		return;
 	prev_jiffy = jiffies;