sched: Make separate sched*.c translation units

Since once needs to do something at conferences and fixing compile
warnings doesn't actually require much if any attention I decided
to break up the sched.c #include "*.c" fest.

This further modularizes the scheduler code.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-x0fcd3mnp8f9c99grcpewmhi@git.kernel.orgSigned-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/latencytop.h

@@ -10,6 +10,8 @@
 #define _INCLUDE_GUARD_LATENCYTOP_H_
 
 #include <linux/compiler.h>
+struct task_struct;
+
 #ifdef CONFIG_LATENCYTOP
 
 #define LT_SAVECOUNT		32
@@ -23,7 +25,6 @@ struct latency_record {
 };
 
 
-struct task_struct;
 
 extern int latencytop_enabled;
 void __account_scheduler_latency(struct task_struct *task, int usecs, int inter);

include/linux/sched.h

@@ -925,6 +925,15 @@ static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
 	return to_cpumask(sg->cpumask);
 }
 
+/**
+ * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
+ * @group: The group whose first cpu is to be returned.
+ */
+static inline unsigned int group_first_cpu(struct sched_group *group)
+{
+	return cpumask_first(sched_group_cpus(group));
+}
+
 struct sched_domain_attr {
 	int relax_domain_level;
 };

kernel/Makefile

@@ -2,7 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-obj-y     = sched.o fork.o exec_domain.o panic.o printk.o \
+obj-y     = fork.o exec_domain.o panic.o printk.o \
 	    cpu.o exit.o itimer.o time.o softirq.o resource.o \
 	    sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
 	    signal.o sys.o kmod.o workqueue.o pid.o \
@@ -10,8 +10,12 @@ obj-y     = sched.o fork.o exec_domain.o panic.o printk.o \
 	    kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
 	    hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
 	    notifier.o ksysfs.o sched_clock.o cred.o \
-	    async.o range.o
-obj-y += groups.o
+	    async.o range.o groups.o
+
+obj-y += sched.o sched_idletask.o sched_fair.o sched_rt.o sched_stoptask.o
+obj-$(CONFIG_SCHED_AUTOGROUP) += sched_autogroup.o
+obj-$(CONFIG_SCHEDSTATS) += sched_stats.o
+obj-$(CONFIG_SCHED_DEBUG) += sched_debug.o
 
 ifdef CONFIG_FUNCTION_TRACER
 # Do not trace debug files and internal ftrace files

kernel/sched_autogroup.c

 #ifdef CONFIG_SCHED_AUTOGROUP
 
+#include "sched.h"
+
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/kallsyms.h>
 #include <linux/utsname.h>
+#include <linux/security.h>
+#include <linux/export.h>
 
 unsigned int __read_mostly sysctl_sched_autogroup_enabled = 1;
 static struct autogroup autogroup_default;
 static atomic_t autogroup_seq_nr;
 
-static void __init autogroup_init(struct task_struct *init_task)
+void __init autogroup_init(struct task_struct *init_task)
 {
 	autogroup_default.tg = &root_task_group;
 	kref_init(&autogroup_default.kref);
@@ -17,7 +21,7 @@ static void __init autogroup_init(struct task_struct *init_task)
 	init_task->signal->autogroup = &autogroup_default;
 }
 
-static inline void autogroup_free(struct task_group *tg)
+void autogroup_free(struct task_group *tg)
 {
 	kfree(tg->autogroup);
 }
@@ -59,10 +63,6 @@ static inline struct autogroup *autogroup_task_get(struct task_struct *p)
 	return ag;
 }
 
-#ifdef CONFIG_RT_GROUP_SCHED
-static void free_rt_sched_group(struct task_group *tg);
-#endif
-
 static inline struct autogroup *autogroup_create(void)
 {
 	struct autogroup *ag = kzalloc(sizeof(*ag), GFP_KERNEL);
@@ -108,8 +108,7 @@ static inline struct autogroup *autogroup_create(void)
 	return autogroup_kref_get(&autogroup_default);
 }
 
-static inline bool
-task_wants_autogroup(struct task_struct *p, struct task_group *tg)
+bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
 {
 	if (tg != &root_task_group)
 		return false;
@@ -127,22 +126,6 @@ task_wants_autogroup(struct task_struct *p, struct task_group *tg)
 	return true;
 }
 
-static inline bool task_group_is_autogroup(struct task_group *tg)
-{
-	return !!tg->autogroup;
-}
-
-static inline struct task_group *
-autogroup_task_group(struct task_struct *p, struct task_group *tg)
-{
-	int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);
-
-	if (enabled && task_wants_autogroup(p, tg))
-		return p->signal->autogroup->tg;
-
-	return tg;
-}
-
 static void
 autogroup_move_group(struct task_struct *p, struct autogroup *ag)
 {
@@ -263,7 +246,7 @@ void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m)
 #endif /* CONFIG_PROC_FS */
 
 #ifdef CONFIG_SCHED_DEBUG
-static inline int autogroup_path(struct task_group *tg, char *buf, int buflen)
+int autogroup_path(struct task_group *tg, char *buf, int buflen)
 {
 	if (!task_group_is_autogroup(tg))
 		return 0;

kernel/sched_autogroup.h

 #ifdef CONFIG_SCHED_AUTOGROUP
 
+#include <linux/kref.h>
+#include <linux/rwsem.h>
+
 struct autogroup {
 	/*
 	 * reference doesn't mean how many thread attach to this
@@ -13,9 +16,28 @@ struct autogroup {
 	int			nice;
 };
 
-static inline bool task_group_is_autogroup(struct task_group *tg);
+extern void autogroup_init(struct task_struct *init_task);
+extern void autogroup_free(struct task_group *tg);
+
+static inline bool task_group_is_autogroup(struct task_group *tg)
+{
+	return !!tg->autogroup;
+}
+
+extern bool task_wants_autogroup(struct task_struct *p, struct task_group *tg);
+
 static inline struct task_group *
-autogroup_task_group(struct task_struct *p, struct task_group *tg);
+autogroup_task_group(struct task_struct *p, struct task_group *tg)
+{
+	int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);
+
+	if (enabled && task_wants_autogroup(p, tg))
+		return p->signal->autogroup->tg;
+
+	return tg;
+}
+
+extern int autogroup_path(struct task_group *tg, char *buf, int buflen);
 
 #else /* !CONFIG_SCHED_AUTOGROUP */
 

kernel/sched_debug.c

@@ -16,6 +16,8 @@
 #include <linux/kallsyms.h>
 #include <linux/utsname.h>
 
+#include "sched.h"
+
 static DEFINE_SPINLOCK(sched_debug_lock);
 
 /*
@@ -373,7 +375,7 @@ static int sched_debug_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static void sysrq_sched_debug_show(void)
+void sysrq_sched_debug_show(void)
 {
 	sched_debug_show(NULL, NULL);
 }

kernel/sched_idletask.c

+#include "sched.h"
+
 /*
  * idle-task scheduling class.
  *
@@ -71,7 +73,7 @@ static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task
 /*
  * Simple, special scheduling class for the per-CPU idle tasks:
  */
-static const struct sched_class idle_sched_class = {
+const struct sched_class idle_sched_class = {
 	/* .next is NULL */
 	/* no enqueue/yield_task for idle tasks */
 

kernel/sched_rt.c

@@ -3,7 +3,92 @@
  * policies)
  */
 
+#include "sched.h"
+
+#include <linux/slab.h>
+
+static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
+
+struct rt_bandwidth def_rt_bandwidth;
+
+static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)
+{
+	struct rt_bandwidth *rt_b =
+		container_of(timer, struct rt_bandwidth, rt_period_timer);
+	ktime_t now;
+	int overrun;
+	int idle = 0;
+
+	for (;;) {
+		now = hrtimer_cb_get_time(timer);
+		overrun = hrtimer_forward(timer, now, rt_b->rt_period);
+
+		if (!overrun)
+			break;
+
+		idle = do_sched_rt_period_timer(rt_b, overrun);
+	}
+
+	return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
+}
+
+void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
+{
+	rt_b->rt_period = ns_to_ktime(period);
+	rt_b->rt_runtime = runtime;
+
+	raw_spin_lock_init(&rt_b->rt_runtime_lock);
+
+	hrtimer_init(&rt_b->rt_period_timer,
+			CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	rt_b->rt_period_timer.function = sched_rt_period_timer;
+}
+
+static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
+{
+	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
+		return;
+
+	if (hrtimer_active(&rt_b->rt_period_timer))
+		return;
+
+	raw_spin_lock(&rt_b->rt_runtime_lock);
+	start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period);
+	raw_spin_unlock(&rt_b->rt_runtime_lock);
+}
+
+void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
+{
+	struct rt_prio_array *array;
+	int i;
+
+	array = &rt_rq->active;
+	for (i = 0; i < MAX_RT_PRIO; i++) {
+		INIT_LIST_HEAD(array->queue + i);
+		__clear_bit(i, array->bitmap);
+	}
+	/* delimiter for bitsearch: */
+	__set_bit(MAX_RT_PRIO, array->bitmap);
+
+#if defined CONFIG_SMP
+	rt_rq->highest_prio.curr = MAX_RT_PRIO;
+	rt_rq->highest_prio.next = MAX_RT_PRIO;
+	rt_rq->rt_nr_migratory = 0;
+	rt_rq->overloaded = 0;
+	plist_head_init(&rt_rq->pushable_tasks);
+#endif
+
+	rt_rq->rt_time = 0;
+	rt_rq->rt_throttled = 0;
+	rt_rq->rt_runtime = 0;
+	raw_spin_lock_init(&rt_rq->rt_runtime_lock);
+}
+
 #ifdef CONFIG_RT_GROUP_SCHED
+static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
+{
+	hrtimer_cancel(&rt_b->rt_period_timer);
+}
 
 #define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
 
@@ -25,6 +110,91 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
 	return rt_se->rt_rq;
 }
 
+void free_rt_sched_group(struct task_group *tg)
+{
+	int i;
+
+	if (tg->rt_se)
+		destroy_rt_bandwidth(&tg->rt_bandwidth);
+
+	for_each_possible_cpu(i) {
+		if (tg->rt_rq)
+			kfree(tg->rt_rq[i]);
+		if (tg->rt_se)
+			kfree(tg->rt_se[i]);
+	}
+
+	kfree(tg->rt_rq);
+	kfree(tg->rt_se);
+}
+
+void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
+		struct sched_rt_entity *rt_se, int cpu,
+		struct sched_rt_entity *parent)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	rt_rq->highest_prio.curr = MAX_RT_PRIO;
+	rt_rq->rt_nr_boosted = 0;
+	rt_rq->rq = rq;
+	rt_rq->tg = tg;
+
+	tg->rt_rq[cpu] = rt_rq;
+	tg->rt_se[cpu] = rt_se;
+
+	if (!rt_se)
+		return;
+
+	if (!parent)
+		rt_se->rt_rq = &rq->rt;
+	else
+		rt_se->rt_rq = parent->my_q;
+
+	rt_se->my_q = rt_rq;
+	rt_se->parent = parent;
+	INIT_LIST_HEAD(&rt_se->run_list);
+}
+
+int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
+{
+	struct rt_rq *rt_rq;
+	struct sched_rt_entity *rt_se;
+	int i;
+
+	tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
+	if (!tg->rt_rq)
+		goto err;
+	tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
+	if (!tg->rt_se)
+		goto err;
+
+	init_rt_bandwidth(&tg->rt_bandwidth,
+			ktime_to_ns(def_rt_bandwidth.rt_period), 0);
+
+	for_each_possible_cpu(i) {
+		rt_rq = kzalloc_node(sizeof(struct rt_rq),
+				     GFP_KERNEL, cpu_to_node(i));
+		if (!rt_rq)
+			goto err;
+
+		rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
+				     GFP_KERNEL, cpu_to_node(i));
+		if (!rt_se)
+			goto err_free_rq;
+
+		init_rt_rq(rt_rq, cpu_rq(i));
+		rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;
+		init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);
+	}
+
+	return 1;
+
+err_free_rq:
+	kfree(rt_rq);
+err:
+	return 0;
+}
+
 #else /* CONFIG_RT_GROUP_SCHED */
 
 #define rt_entity_is_task(rt_se) (1)
@@ -47,6 +217,12 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
 	return &rq->rt;
 }
 
+void free_rt_sched_group(struct task_group *tg) { }
+
+int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
+{
+	return 1;
+}
 #endif /* CONFIG_RT_GROUP_SCHED */
 
 #ifdef CONFIG_SMP
@@ -556,6 +732,28 @@ static void enable_runtime(struct rq *rq)
 	raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 
+int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+	int cpu = (int)(long)hcpu;
+
+	switch (action) {
+	case CPU_DOWN_PREPARE:
+	case CPU_DOWN_PREPARE_FROZEN:
+		disable_runtime(cpu_rq(cpu));
+		return NOTIFY_OK;
+
+	case CPU_DOWN_FAILED:
+	case CPU_DOWN_FAILED_FROZEN:
+	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
+		enable_runtime(cpu_rq(cpu));
+		return NOTIFY_OK;
+
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
 static int balance_runtime(struct rt_rq *rt_rq)
 {
 	int more = 0;
@@ -1178,8 +1376,6 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 /* Only try algorithms three times */
 #define RT_MAX_TRIES 3
 
-static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep);
-
 static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
@@ -1653,13 +1849,14 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
 		pull_rt_task(rq);
 }
 
-static inline void init_sched_rt_class(void)
+void init_sched_rt_class(void)
 {
 	unsigned int i;
 
-	for_each_possible_cpu(i)
+	for_each_possible_cpu(i) {
 		zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
 					GFP_KERNEL, cpu_to_node(i));
+	}
 }
 #endif /* CONFIG_SMP */
 
@@ -1800,7 +1997,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
 		return 0;
 }
 
-static const struct sched_class rt_sched_class = {
+const struct sched_class rt_sched_class = {
 	.next			= &fair_sched_class,
 	.enqueue_task		= enqueue_task_rt,
 	.dequeue_task		= dequeue_task_rt,
@@ -1835,7 +2032,7 @@ static const struct sched_class rt_sched_class = {
 #ifdef CONFIG_SCHED_DEBUG
 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
 
-static void print_rt_stats(struct seq_file *m, int cpu)
+void print_rt_stats(struct seq_file *m, int cpu)
 {
 	rt_rq_iter_t iter;
 	struct rt_rq *rt_rq;

kernel/sched_stats.c

+
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+
+#include "sched.h"
+
+/*
+ * bump this up when changing the output format or the meaning of an existing
+ * format, so that tools can adapt (or abort)
+ */
+#define SCHEDSTAT_VERSION 15
+
+static int show_schedstat(struct seq_file *seq, void *v)
+{
+	int cpu;
+	int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
+	char *mask_str = kmalloc(mask_len, GFP_KERNEL);
+
+	if (mask_str == NULL)
+		return -ENOMEM;
+
+	seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
+	seq_printf(seq, "timestamp %lu\n", jiffies);
+	for_each_online_cpu(cpu) {
+		struct rq *rq = cpu_rq(cpu);
+#ifdef CONFIG_SMP
+		struct sched_domain *sd;
+		int dcount = 0;
+#endif
+
+		/* runqueue-specific stats */
+		seq_printf(seq,
+		    "cpu%d %u %u %u %u %u %u %llu %llu %lu",
+		    cpu, rq->yld_count,
+		    rq->sched_switch, rq->sched_count, rq->sched_goidle,
+		    rq->ttwu_count, rq->ttwu_local,
+		    rq->rq_cpu_time,
+		    rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
+
+		seq_printf(seq, "\n");
+
+#ifdef CONFIG_SMP
+		/* domain-specific stats */
+		rcu_read_lock();
+		for_each_domain(cpu, sd) {
+			enum cpu_idle_type itype;
+
+			cpumask_scnprintf(mask_str, mask_len,
+					  sched_domain_span(sd));
+			seq_printf(seq, "domain%d %s", dcount++, mask_str);
+			for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
+					itype++) {
+				seq_printf(seq, " %u %u %u %u %u %u %u %u",
+				    sd->lb_count[itype],
+				    sd->lb_balanced[itype],
+				    sd->lb_failed[itype],
+				    sd->lb_imbalance[itype],
+				    sd->lb_gained[itype],
+				    sd->lb_hot_gained[itype],
+				    sd->lb_nobusyq[itype],
+				    sd->lb_nobusyg[itype]);
+			}
+			seq_printf(seq,
+				   " %u %u %u %u %u %u %u %u %u %u %u %u\n",
+			    sd->alb_count, sd->alb_failed, sd->alb_pushed,
+			    sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
+			    sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
+			    sd->ttwu_wake_remote, sd->ttwu_move_affine,
+			    sd->ttwu_move_balance);
+		}
+		rcu_read_unlock();
+#endif
+	}
+	kfree(mask_str);
+	return 0;
+}
+
+static int schedstat_open(struct inode *inode, struct file *file)
+{
+	unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
+	char *buf = kmalloc(size, GFP_KERNEL);
+	struct seq_file *m;
+	int res;
+
+	if (!buf)
+		return -ENOMEM;
+	res = single_open(file, show_schedstat, NULL);
+	if (!res) {
+		m = file->private_data;
+		m->buf = buf;
+		m->size = size;
+	} else
+		kfree(buf);
+	return res;
+}
+
+static const struct file_operations proc_schedstat_operations = {
+	.open    = schedstat_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release,
+};
+
+static int __init proc_schedstat_init(void)
+{
+	proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
+	return 0;
+}
+module_init(proc_schedstat_init);

kernel/sched_stats.h

 
 #ifdef CONFIG_SCHEDSTATS
-/*
- * bump this up when changing the output format or the meaning of an existing
- * format, so that tools can adapt (or abort)
- */
-#define SCHEDSTAT_VERSION 15
-
-static int show_schedstat(struct seq_file *seq, void *v)
-{
-	int cpu;
-	int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
-	char *mask_str = kmalloc(mask_len, GFP_KERNEL);
-
-	if (mask_str == NULL)
-		return -ENOMEM;
-
-	seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
-	seq_printf(seq, "timestamp %lu\n", jiffies);
-	for_each_online_cpu(cpu) {
-		struct rq *rq = cpu_rq(cpu);
-#ifdef CONFIG_SMP
-		struct sched_domain *sd;
-		int dcount = 0;
-#endif
-
-		/* runqueue-specific stats */
-		seq_printf(seq,
-		    "cpu%d %u %u %u %u %u %u %llu %llu %lu",
-		    cpu, rq->yld_count,
-		    rq->sched_switch, rq->sched_count, rq->sched_goidle,
-		    rq->ttwu_count, rq->ttwu_local,
-		    rq->rq_cpu_time,
-		    rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
-
-		seq_printf(seq, "\n");
-
-#ifdef CONFIG_SMP
-		/* domain-specific stats */
-		rcu_read_lock();
-		for_each_domain(cpu, sd) {
-			enum cpu_idle_type itype;
-
-			cpumask_scnprintf(mask_str, mask_len,
-					  sched_domain_span(sd));
-			seq_printf(seq, "domain%d %s", dcount++, mask_str);
-			for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
-					itype++) {
-				seq_printf(seq, " %u %u %u %u %u %u %u %u",
-				    sd->lb_count[itype],
-				    sd->lb_balanced[itype],
-				    sd->lb_failed[itype],
-				    sd->lb_imbalance[itype],
-				    sd->lb_gained[itype],
-				    sd->lb_hot_gained[itype],
-				    sd->lb_nobusyq[itype],
-				    sd->lb_nobusyg[itype]);
-			}
-			seq_printf(seq,
-				   " %u %u %u %u %u %u %u %u %u %u %u %u\n",
-			    sd->alb_count, sd->alb_failed, sd->alb_pushed,
-			    sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
-			    sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
-			    sd->ttwu_wake_remote, sd->ttwu_move_affine,
-			    sd->ttwu_move_balance);
-		}
-		rcu_read_unlock();
-#endif
-	}
-	kfree(mask_str);
-	return 0;
-}
-
-static int schedstat_open(struct inode *inode, struct file *file)
-{
-	unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
-	char *buf = kmalloc(size, GFP_KERNEL);
-	struct seq_file *m;
-	int res;
-
-	if (!buf)
-		return -ENOMEM;
-	res = single_open(file, show_schedstat, NULL);
-	if (!res) {
-		m = file->private_data;
-		m->buf = buf;
-		m->size = size;
-	} else
-		kfree(buf);
-	return res;
-}
-
-static const struct file_operations proc_schedstat_operations = {
-	.open    = schedstat_open,
-	.read    = seq_read,
-	.llseek  = seq_lseek,
-	.release = single_release,
-};
-
-static int __init proc_schedstat_init(void)
-{
-	proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
-	return 0;
-}
-module_init(proc_schedstat_init);
 
 /*
  * Expects runqueue lock to be held for atomicity of update

kernel/sched_stoptask.c

+#include "sched.h"
+
 /*
  * stop-task scheduling class.
  *
@@ -80,7 +82,7 @@ get_rr_interval_stop(struct rq *rq, struct task_struct *task)
 /*
  * Simple, special scheduling class for the per-CPU stop tasks:
  */
-static const struct sched_class stop_sched_class = {
+const struct sched_class stop_sched_class = {
 	.next			= &rt_sched_class,
 
 	.enqueue_task		= enqueue_task_stop,