Merge branch 'sched/core'

include/linux/cpuset.h

@@ -15,6 +15,7 @@
 #include <linux/cpumask.h>
 #include <linux/nodemask.h>
 #include <linux/mm.h>
+#include <linux/mmu_context.h>
 #include <linux/jump_label.h>
 
 #ifdef CONFIG_CPUSETS
@@ -58,7 +59,7 @@ extern void cpuset_wait_for_hotplug(void);
 extern void cpuset_read_lock(void);
 extern void cpuset_read_unlock(void);
 extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
-extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
+extern bool cpuset_cpus_allowed_fallback(struct task_struct *p);
 extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
 #define cpuset_current_mems_allowed (current->mems_allowed)
 void cpuset_init_current_mems_allowed(void);
@@ -184,11 +185,12 @@ static inline void cpuset_read_unlock(void) { }
 static inline void cpuset_cpus_allowed(struct task_struct *p,
 				       struct cpumask *mask)
 {
-	cpumask_copy(mask, cpu_possible_mask);
+	cpumask_copy(mask, task_cpu_possible_mask(p));
 }
 
-static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
+static inline bool cpuset_cpus_allowed_fallback(struct task_struct *p)
 {
+	return false;
 }
 
 static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)

include/linux/mmu_context.h

@@ -14,4 +14,18 @@
 static inline void leave_mm(int cpu) { }
 #endif
 
+/*
+ * CPUs that are capable of running user task @p. Must contain at least one
+ * active CPU. It is assumed that the kernel can run on all CPUs, so calling
+ * this for a kernel thread is pointless.
+ *
+ * By default, we assume a sane, homogeneous system.
+ */
+#ifndef task_cpu_possible_mask
+# define task_cpu_possible_mask(p)	cpu_possible_mask
+# define task_cpu_possible(cpu, p)	true
+#else
+# define task_cpu_possible(cpu, p)	cpumask_test_cpu((cpu), task_cpu_possible_mask(p))
+#endif
+
 #endif

include/linux/sched.h

@@ -748,6 +748,7 @@ struct task_struct {
 	unsigned int			policy;
 	int				nr_cpus_allowed;
 	const cpumask_t			*cpus_ptr;
+	cpumask_t			*user_cpus_ptr;
 	cpumask_t			cpus_mask;
 	void				*migration_pending;
 #ifdef CONFIG_SMP
@@ -1705,6 +1706,11 @@ extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_
 #ifdef CONFIG_SMP
 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
+extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
+extern void release_user_cpus_ptr(struct task_struct *p);
+extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
+extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
+extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
 #else
 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
 {
@@ -1715,6 +1721,21 @@ static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpuma
 		return -EINVAL;
 	return 0;
 }
+static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
+{
+	if (src->user_cpus_ptr)
+		return -EINVAL;
+	return 0;
+}
+static inline void release_user_cpus_ptr(struct task_struct *p)
+{
+	WARN_ON(p->user_cpus_ptr);
+}
+
+static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
+{
+	return 0;
+}
 #endif
 
 extern int yield_to(struct task_struct *p, bool preempt);

include/linux/sched/sysctl.h

@@ -28,30 +28,12 @@ enum { sysctl_hung_task_timeout_secs = 0 };
 
 extern unsigned int sysctl_sched_child_runs_first;
 
-extern unsigned int sysctl_sched_latency;
-extern unsigned int sysctl_sched_min_granularity;
-extern unsigned int sysctl_sched_wakeup_granularity;
-
 enum sched_tunable_scaling {
 	SCHED_TUNABLESCALING_NONE,
 	SCHED_TUNABLESCALING_LOG,
 	SCHED_TUNABLESCALING_LINEAR,
 	SCHED_TUNABLESCALING_END,
 };
-extern unsigned int sysctl_sched_tunable_scaling;
-
-extern unsigned int sysctl_numa_balancing_scan_delay;
-extern unsigned int sysctl_numa_balancing_scan_period_min;
-extern unsigned int sysctl_numa_balancing_scan_period_max;
-extern unsigned int sysctl_numa_balancing_scan_size;
-
-#ifdef CONFIG_SCHED_DEBUG
-extern __read_mostly unsigned int sysctl_sched_migration_cost;
-extern __read_mostly unsigned int sysctl_sched_nr_migrate;
-
-extern int sysctl_resched_latency_warn_ms;
-extern int sysctl_resched_latency_warn_once;
-#endif
 
 /*
  *  control realtime throttling:

include/linux/wait.h

@@ -56,7 +56,7 @@ struct task_struct;
 
 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) {					\
 	.lock		= __SPIN_LOCK_UNLOCKED(name.lock),			\
-	.head		= { &(name).head, &(name).head } }
+	.head		= LIST_HEAD_INIT(name.head) }
 
 #define DECLARE_WAIT_QUEUE_HEAD(name) \
 	struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name)

init/init_task.c

@@ -80,6 +80,7 @@ struct task_struct init_task
 	.normal_prio	= MAX_PRIO - 20,
 	.policy		= SCHED_NORMAL,
 	.cpus_ptr	= &init_task.cpus_mask,
+	.user_cpus_ptr	= NULL,
 	.cpus_mask	= CPU_MASK_ALL,
 	.nr_cpus_allowed= NR_CPUS,
 	.mm		= NULL,

kernel/cgroup/cpuset.c

@@ -372,18 +372,29 @@ static inline bool is_in_v2_mode(void)
 }
 
 /*
- * Return in pmask the portion of a cpusets's cpus_allowed that
- * are online.  If none are online, walk up the cpuset hierarchy
- * until we find one that does have some online cpus.
+ * Return in pmask the portion of a task's cpusets's cpus_allowed that
+ * are online and are capable of running the task.  If none are found,
+ * walk up the cpuset hierarchy until we find one that does have some
+ * appropriate cpus.
  *
  * One way or another, we guarantee to return some non-empty subset
  * of cpu_online_mask.
  *
  * Call with callback_lock or cpuset_mutex held.
  */
-static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
+static void guarantee_online_cpus(struct task_struct *tsk,
+				  struct cpumask *pmask)
 {
-	while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) {
+	const struct cpumask *possible_mask = task_cpu_possible_mask(tsk);
+	struct cpuset *cs;
+
+	if (WARN_ON(!cpumask_and(pmask, possible_mask, cpu_online_mask)))
+		cpumask_copy(pmask, cpu_online_mask);
+
+	rcu_read_lock();
+	cs = task_cs(tsk);
+
+	while (!cpumask_intersects(cs->effective_cpus, pmask)) {
 		cs = parent_cs(cs);
 		if (unlikely(!cs)) {
 			/*
@@ -393,11 +404,13 @@ static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
 			 * cpuset's effective_cpus is on its way to be
 			 * identical to cpu_online_mask.
 			 */
-			cpumask_copy(pmask, cpu_online_mask);
-			return;
+			goto out_unlock;
 		}
 	}
-	cpumask_and(pmask, cs->effective_cpus, cpu_online_mask);
+	cpumask_and(pmask, pmask, cs->effective_cpus);
+
+out_unlock:
+	rcu_read_unlock();
 }
 
 /*
@@ -2199,15 +2212,13 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 
 	percpu_down_write(&cpuset_rwsem);
 
-	/* prepare for attach */
-	if (cs == &top_cpuset)
-		cpumask_copy(cpus_attach, cpu_possible_mask);
-	else
-		guarantee_online_cpus(cs, cpus_attach);
-
 	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
 
 	cgroup_taskset_for_each(task, css, tset) {
+		if (cs != &top_cpuset)
+			guarantee_online_cpus(task, cpus_attach);
+		else
+			cpumask_copy(cpus_attach, task_cpu_possible_mask(task));
 		/*
 		 * can_attach beforehand should guarantee that this doesn't
 		 * fail.  TODO: have a better way to handle failure here
@@ -3302,9 +3313,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
 	unsigned long flags;
 
 	spin_lock_irqsave(&callback_lock, flags);
-	rcu_read_lock();
-	guarantee_online_cpus(task_cs(tsk), pmask);
-	rcu_read_unlock();
+	guarantee_online_cpus(tsk, pmask);
 	spin_unlock_irqrestore(&callback_lock, flags);
 }
 
@@ -3318,13 +3327,22 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
  * which will not contain a sane cpumask during cases such as cpu hotplugging.
  * This is the absolute last resort for the scheduler and it is only used if
  * _every_ other avenue has been traveled.
+ *
+ * Returns true if the affinity of @tsk was changed, false otherwise.
  **/
 
-void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
+bool cpuset_cpus_allowed_fallback(struct task_struct *tsk)
 {
+	const struct cpumask *possible_mask = task_cpu_possible_mask(tsk);
+	const struct cpumask *cs_mask;
+	bool changed = false;
+
 	rcu_read_lock();
-	do_set_cpus_allowed(tsk, is_in_v2_mode() ?
-		task_cs(tsk)->cpus_allowed : cpu_possible_mask);
+	cs_mask = task_cs(tsk)->cpus_allowed;
+	if (is_in_v2_mode() && cpumask_subset(cs_mask, possible_mask)) {
+		do_set_cpus_allowed(tsk, cs_mask);
+		changed = true;
+	}
 	rcu_read_unlock();
 
 	/*
@@ -3344,6 +3362,7 @@ void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
 	 * select_fallback_rq() will fix things ups and set cpu_possible_mask
 	 * if required.
 	 */
+	return changed;
 }
 
 void __init cpuset_init_current_mems_allowed(void)

kernel/fork.c

@@ -446,6 +446,7 @@ void put_task_stack(struct task_struct *tsk)
 
 void free_task(struct task_struct *tsk)
 {
+	release_user_cpus_ptr(tsk);
 	scs_release(tsk);
 
 #ifndef CONFIG_THREAD_INFO_IN_TASK
@@ -924,6 +925,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 #endif
 	if (orig->cpus_ptr == &orig->cpus_mask)
 		tsk->cpus_ptr = &tsk->cpus_mask;
+	dup_user_cpus_ptr(tsk, orig, node);
 
 	/*
 	 * One for the user space visible state that goes away when reaped.

kernel/sched/deadline.c

@@ -1733,6 +1733,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused
 	 */
 	raw_spin_rq_lock(rq);
 	if (p->dl.dl_non_contending) {
+		update_rq_clock(rq);
 		sub_running_bw(&p->dl, &rq->dl);
 		p->dl.dl_non_contending = 0;
 		/*
@@ -2741,7 +2742,7 @@ void __setparam_dl(struct task_struct *p, const struct sched_attr *attr)
 	dl_se->dl_runtime = attr->sched_runtime;
 	dl_se->dl_deadline = attr->sched_deadline;
 	dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;
-	dl_se->flags = attr->sched_flags;
+	dl_se->flags = attr->sched_flags & SCHED_DL_FLAGS;
 	dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);
 	dl_se->dl_density = to_ratio(dl_se->dl_deadline, dl_se->dl_runtime);
 }
@@ -2754,7 +2755,8 @@ void __getparam_dl(struct task_struct *p, struct sched_attr *attr)
 	attr->sched_runtime = dl_se->dl_runtime;
 	attr->sched_deadline = dl_se->dl_deadline;
 	attr->sched_period = dl_se->dl_period;
-	attr->sched_flags = dl_se->flags;
+	attr->sched_flags &= ~SCHED_DL_FLAGS;
+	attr->sched_flags |= dl_se->flags;
 }
 
 /*
@@ -2851,7 +2853,7 @@ bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
 	if (dl_se->dl_runtime != attr->sched_runtime ||
 	    dl_se->dl_deadline != attr->sched_deadline ||
 	    dl_se->dl_period != attr->sched_period ||
-	    dl_se->flags != attr->sched_flags)
+	    dl_se->flags != (attr->sched_flags & SCHED_DL_FLAGS))
 		return true;
 
 	return false;

kernel/sched/debug.c

@@ -388,6 +388,13 @@ void update_sched_domain_debugfs(void)
 {
 	int cpu, i;
 
+	/*
+	 * This can unfortunately be invoked before sched_debug_init() creates
+	 * the debug directory. Don't touch sd_sysctl_cpus until then.
+	 */
+	if (!debugfs_sched)
+		return;
+
 	if (!cpumask_available(sd_sysctl_cpus)) {
 		if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL))
 			return;
@@ -600,6 +607,9 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 	SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
 			cfs_rq->nr_spread_over);
 	SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
+	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running);
+	SEQ_printf(m, "  .%-30s: %d\n", "idle_h_nr_running",
+			cfs_rq->idle_h_nr_running);
 	SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
 #ifdef CONFIG_SMP
 	SEQ_printf(m, "  .%-30s: %lu\n", "load_avg",

kernel/sched/sched.h

@@ -227,6 +227,8 @@ static inline void update_avg(u64 *avg, u64 sample)
  */
 #define SCHED_FLAG_SUGOV	0x10000000
 
+#define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV)
+
 static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se)
 {
 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
@@ -394,6 +396,9 @@ struct task_group {
 	struct cfs_rq		**cfs_rq;
 	unsigned long		shares;
 
+	/* A positive value indicates that this is a SCHED_IDLE group. */
+	int			idle;
+
 #ifdef	CONFIG_SMP
 	/*
 	 * load_avg can be heavily contended at clock tick time, so put
@@ -503,6 +508,8 @@ extern void sched_move_task(struct task_struct *tsk);
 #ifdef CONFIG_FAIR_GROUP_SCHED
 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
 
+extern int sched_group_set_idle(struct task_group *tg, long idle);
+
 #ifdef CONFIG_SMP
 extern void set_task_rq_fair(struct sched_entity *se,
 			     struct cfs_rq *prev, struct cfs_rq *next);
@@ -599,6 +606,9 @@ struct cfs_rq {
 	struct list_head	leaf_cfs_rq_list;
 	struct task_group	*tg;	/* group that "owns" this runqueue */
 
+	/* Locally cached copy of our task_group's idle value */
+	int			idle;
+
 #ifdef CONFIG_CFS_BANDWIDTH
 	int			runtime_enabled;
 	s64			runtime_remaining;
@@ -2234,6 +2244,7 @@ extern struct task_struct *pick_next_task_idle(struct rq *rq);
 #define SCA_CHECK		0x01
 #define SCA_MIGRATE_DISABLE	0x02
 #define SCA_MIGRATE_ENABLE	0x04
+#define SCA_USER		0x08
 
 #ifdef CONFIG_SMP
 
@@ -2385,6 +2396,21 @@ extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
 extern const_debug unsigned int sysctl_sched_nr_migrate;
 extern const_debug unsigned int sysctl_sched_migration_cost;
 
+#ifdef CONFIG_SCHED_DEBUG
+extern unsigned int sysctl_sched_latency;
+extern unsigned int sysctl_sched_min_granularity;
+extern unsigned int sysctl_sched_wakeup_granularity;
+extern int sysctl_resched_latency_warn_ms;
+extern int sysctl_resched_latency_warn_once;
+
+extern unsigned int sysctl_sched_tunable_scaling;
+
+extern unsigned int sysctl_numa_balancing_scan_delay;
+extern unsigned int sysctl_numa_balancing_scan_period_min;
+extern unsigned int sysctl_numa_balancing_scan_period_max;
+extern unsigned int sysctl_numa_balancing_scan_size;
+#endif
+
 #ifdef CONFIG_SCHED_HRTICK
 
 /*

kernel/sched/topology.c

@@ -1482,6 +1482,8 @@ int				sched_max_numa_distance;
 static int			*sched_domains_numa_distance;
 static struct cpumask		***sched_domains_numa_masks;
 int __read_mostly		node_reclaim_distance = RECLAIM_DISTANCE;
+
+static unsigned long __read_mostly *sched_numa_onlined_nodes;
 #endif
 
 /*
@@ -1833,6 +1835,16 @@ void sched_init_numa(void)
 			sched_domains_numa_masks[i][j] = mask;
 
 			for_each_node(k) {
+				/*
+				 * Distance information can be unreliable for
+				 * offline nodes, defer building the node
+				 * masks to its bringup.
+				 * This relies on all unique distance values
+				 * still being visible at init time.
+				 */
+				if (!node_online(j))
+					continue;
+
 				if (sched_debug() && (node_distance(j, k) != node_distance(k, j)))
 					sched_numa_warn("Node-distance not symmetric");
 
@@ -1886,6 +1898,53 @@ void sched_init_numa(void)
 	sched_max_numa_distance = sched_domains_numa_distance[nr_levels - 1];
 
 	init_numa_topology_type();
+
+	sched_numa_onlined_nodes = bitmap_alloc(nr_node_ids, GFP_KERNEL);
+	if (!sched_numa_onlined_nodes)
+		return;
+
+	bitmap_zero(sched_numa_onlined_nodes, nr_node_ids);
+	for_each_online_node(i)
+		bitmap_set(sched_numa_onlined_nodes, i, 1);
+}
+
+static void __sched_domains_numa_masks_set(unsigned int node)
+{
+	int i, j;
+
+	/*
+	 * NUMA masks are not built for offline nodes in sched_init_numa().
+	 * Thus, when a CPU of a never-onlined-before node gets plugged in,
+	 * adding that new CPU to the right NUMA masks is not sufficient: the
+	 * masks of that CPU's node must also be updated.
+	 */
+	if (test_bit(node, sched_numa_onlined_nodes))
+		return;
+
+	bitmap_set(sched_numa_onlined_nodes, node, 1);
+
+	for (i = 0; i < sched_domains_numa_levels; i++) {
+		for (j = 0; j < nr_node_ids; j++) {
+			if (!node_online(j) || node == j)
+				continue;
+
+			if (node_distance(j, node) > sched_domains_numa_distance[i])
+				continue;
+
+			/* Add remote nodes in our masks */
+			cpumask_or(sched_domains_numa_masks[i][node],
+				   sched_domains_numa_masks[i][node],
+				   sched_domains_numa_masks[0][j]);
+		}
+	}
+
+	/*
+	 * A new node has been brought up, potentially changing the topology
+	 * classification.
+	 *
+	 * Note that this is racy vs any use of sched_numa_topology_type :/
+	 */
+	init_numa_topology_type();
 }
 
 void sched_domains_numa_masks_set(unsigned int cpu)
@@ -1893,8 +1952,14 @@ void sched_domains_numa_masks_set(unsigned int cpu)
 	int node = cpu_to_node(cpu);
 	int i, j;
 
+	__sched_domains_numa_masks_set(node);
+
 	for (i = 0; i < sched_domains_numa_levels; i++) {
 		for (j = 0; j < nr_node_ids; j++) {
+			if (!node_online(j))
+				continue;
+
+			/* Set ourselves in the remote node's masks */
 			if (node_distance(j, node) <= sched_domains_numa_distance[i])
 				cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]);
 		}