1
  2#include <linux/slab.h>
  3#include <linux/fs.h>
  4#include <linux/seq_file.h>
  5#include <linux/proc_fs.h>
  6
  7#include "sched.h"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  8
  9/*
 10 * bump this up when changing the output format or the meaning of an existing
 
 
 11 * format, so that tools can adapt (or abort)
 12 */
 13#define SCHEDSTAT_VERSION 15
 14
 15static int show_schedstat(struct seq_file *seq, void *v)
 16{
 17	int cpu;
 18	int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
 19	char *mask_str = kmalloc(mask_len, GFP_KERNEL);
 20
 21	if (mask_str == NULL)
 22		return -ENOMEM;
 23
 24	if (v == (void *)1) {
 25		seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
 26		seq_printf(seq, "timestamp %lu\n", jiffies);
 27	} else {
 28		struct rq *rq;
 29#ifdef CONFIG_SMP
 30		struct sched_domain *sd;
 31		int dcount = 0;
 32#endif
 33		cpu = (unsigned long)(v - 2);
 34		rq = cpu_rq(cpu);
 35
 36		/* runqueue-specific stats */
 37		seq_printf(seq,
 38		    "cpu%d %u 0 %u %u %u %u %llu %llu %lu",
 39		    cpu, rq->yld_count,
 40		    rq->sched_count, rq->sched_goidle,
 41		    rq->ttwu_count, rq->ttwu_local,
 42		    rq->rq_cpu_time,
 43		    rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
 44
 45		seq_printf(seq, "\n");
 46
 47#ifdef CONFIG_SMP
 48		/* domain-specific stats */
 49		rcu_read_lock();
 50		for_each_domain(cpu, sd) {
 51			enum cpu_idle_type itype;
 52
 53			cpumask_scnprintf(mask_str, mask_len,
 54					  sched_domain_span(sd));
 55			seq_printf(seq, "domain%d %s", dcount++, mask_str);
 56			for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
 57					itype++) {
 58				seq_printf(seq, " %u %u %u %u %u %u %u %u",
 59				    sd->lb_count[itype],
 60				    sd->lb_balanced[itype],
 61				    sd->lb_failed[itype],
 62				    sd->lb_imbalance[itype],
 63				    sd->lb_gained[itype],
 64				    sd->lb_hot_gained[itype],
 65				    sd->lb_nobusyq[itype],
 66				    sd->lb_nobusyg[itype]);
 67			}
 68			seq_printf(seq,
 69				   " %u %u %u %u %u %u %u %u %u %u %u %u\n",
 70			    sd->alb_count, sd->alb_failed, sd->alb_pushed,
 71			    sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
 72			    sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
 73			    sd->ttwu_wake_remote, sd->ttwu_move_affine,
 74			    sd->ttwu_move_balance);
 75		}
 76		rcu_read_unlock();
 77#endif
 78	}
 79	kfree(mask_str);
 80	return 0;
 81}
 82
 83/*
 84 * This itererator needs some explanation.
 85 * It returns 1 for the header position.
 86 * This means 2 is cpu 0.
 87 * In a hotplugged system some cpus, including cpu 0, may be missing so we have
 88 * to use cpumask_* to iterate over the cpus.
 89 */
 90static void *schedstat_start(struct seq_file *file, loff_t *offset)
 91{
 92	unsigned long n = *offset;
 93
 94	if (n == 0)
 95		return (void *) 1;
 96
 97	n--;
 98
 99	if (n > 0)
100		n = cpumask_next(n - 1, cpu_online_mask);
101	else
102		n = cpumask_first(cpu_online_mask);
103
104	*offset = n + 1;
105
106	if (n < nr_cpu_ids)
107		return (void *)(unsigned long)(n + 2);
 
108	return NULL;
109}
110
111static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
112{
113	(*offset)++;
 
114	return schedstat_start(file, offset);
115}
116
117static void schedstat_stop(struct seq_file *file, void *data)
118{
119}
120
121static const struct seq_operations schedstat_sops = {
122	.start = schedstat_start,
123	.next  = schedstat_next,
124	.stop  = schedstat_stop,
125	.show  = show_schedstat,
126};
127
128static int schedstat_open(struct inode *inode, struct file *file)
129{
130	return seq_open(file, &schedstat_sops);
131}
132
133static const struct file_operations proc_schedstat_operations = {
134	.open    = schedstat_open,
135	.read    = seq_read,
136	.llseek  = seq_lseek,
137	.release = seq_release,
138};
139
140static int __init proc_schedstat_init(void)
141{
142	proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
143	return 0;
144}
145subsys_initcall(proc_schedstat_init);

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * /proc/schedstat implementation
  4 */
  5
  6void __update_stats_wait_start(struct rq *rq, struct task_struct *p,
  7			       struct sched_statistics *stats)
  8{
  9	u64 wait_start, prev_wait_start;
 10
 11	wait_start = rq_clock(rq);
 12	prev_wait_start = schedstat_val(stats->wait_start);
 13
 14	if (p && likely(wait_start > prev_wait_start))
 15		wait_start -= prev_wait_start;
 16
 17	__schedstat_set(stats->wait_start, wait_start);
 18}
 19
 20void __update_stats_wait_end(struct rq *rq, struct task_struct *p,
 21			     struct sched_statistics *stats)
 22{
 23	u64 delta = rq_clock(rq) - schedstat_val(stats->wait_start);
 24
 25	if (p) {
 26		if (task_on_rq_migrating(p)) {
 27			/*
 28			 * Preserve migrating task's wait time so wait_start
 29			 * time stamp can be adjusted to accumulate wait time
 30			 * prior to migration.
 31			 */
 32			__schedstat_set(stats->wait_start, delta);
 33
 34			return;
 35		}
 36
 37		trace_sched_stat_wait(p, delta);
 38	}
 39
 40	__schedstat_set(stats->wait_max,
 41			max(schedstat_val(stats->wait_max), delta));
 42	__schedstat_inc(stats->wait_count);
 43	__schedstat_add(stats->wait_sum, delta);
 44	__schedstat_set(stats->wait_start, 0);
 45}
 46
 47void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p,
 48				    struct sched_statistics *stats)
 49{
 50	u64 sleep_start, block_start;
 51
 52	sleep_start = schedstat_val(stats->sleep_start);
 53	block_start = schedstat_val(stats->block_start);
 54
 55	if (sleep_start) {
 56		u64 delta = rq_clock(rq) - sleep_start;
 57
 58		if ((s64)delta < 0)
 59			delta = 0;
 60
 61		if (unlikely(delta > schedstat_val(stats->sleep_max)))
 62			__schedstat_set(stats->sleep_max, delta);
 
 
 63
 64		__schedstat_set(stats->sleep_start, 0);
 65		__schedstat_add(stats->sum_sleep_runtime, delta);
 66
 67		if (p) {
 68			account_scheduler_latency(p, delta >> 10, 1);
 69			trace_sched_stat_sleep(p, delta);
 70		}
 71	}
 72
 73	if (block_start) {
 74		u64 delta = rq_clock(rq) - block_start;
 75
 76		if ((s64)delta < 0)
 77			delta = 0;
 78
 79		if (unlikely(delta > schedstat_val(stats->block_max)))
 80			__schedstat_set(stats->block_max, delta);
 81
 82		__schedstat_set(stats->block_start, 0);
 83		__schedstat_add(stats->sum_sleep_runtime, delta);
 84		__schedstat_add(stats->sum_block_runtime, delta);
 85
 86		if (p) {
 87			if (p->in_iowait) {
 88				__schedstat_add(stats->iowait_sum, delta);
 89				__schedstat_inc(stats->iowait_count);
 90				trace_sched_stat_iowait(p, delta);
 91			}
 92
 93			trace_sched_stat_blocked(p, delta);
 94
 95			/*
 96			 * Blocking time is in units of nanosecs, so shift by
 97			 * 20 to get a milliseconds-range estimation of the
 98			 * amount of time that the task spent sleeping:
 99			 */
100			if (unlikely(prof_on == SLEEP_PROFILING)) {
101				profile_hits(SLEEP_PROFILING,
102					     (void *)get_wchan(p),
103					     delta >> 20);
104			}
105			account_scheduler_latency(p, delta >> 10, 0);
106		}
107	}
108}
109
110/*
111 * Current schedstat API version.
112 *
113 * Bump this up when changing the output format or the meaning of an existing
114 * format, so that tools can adapt (or abort)
115 */
116#define SCHEDSTAT_VERSION 15
117
118static int show_schedstat(struct seq_file *seq, void *v)
119{
120	int cpu;
 
 
 
 
 
121
122	if (v == (void *)1) {
123		seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
124		seq_printf(seq, "timestamp %lu\n", jiffies);
125	} else {
126		struct rq *rq;
127#ifdef CONFIG_SMP
128		struct sched_domain *sd;
129		int dcount = 0;
130#endif
131		cpu = (unsigned long)(v - 2);
132		rq = cpu_rq(cpu);
133
134		/* runqueue-specific stats */
135		seq_printf(seq,
136		    "cpu%d %u 0 %u %u %u %u %llu %llu %lu",
137		    cpu, rq->yld_count,
138		    rq->sched_count, rq->sched_goidle,
139		    rq->ttwu_count, rq->ttwu_local,
140		    rq->rq_cpu_time,
141		    rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
142
143		seq_printf(seq, "\n");
144
145#ifdef CONFIG_SMP
146		/* domain-specific stats */
147		rcu_read_lock();
148		for_each_domain(cpu, sd) {
149			enum cpu_idle_type itype;
150
151			seq_printf(seq, "domain%d %*pb", dcount++,
152				   cpumask_pr_args(sched_domain_span(sd)));
 
153			for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
154					itype++) {
155				seq_printf(seq, " %u %u %u %u %u %u %u %u",
156				    sd->lb_count[itype],
157				    sd->lb_balanced[itype],
158				    sd->lb_failed[itype],
159				    sd->lb_imbalance[itype],
160				    sd->lb_gained[itype],
161				    sd->lb_hot_gained[itype],
162				    sd->lb_nobusyq[itype],
163				    sd->lb_nobusyg[itype]);
164			}
165			seq_printf(seq,
166				   " %u %u %u %u %u %u %u %u %u %u %u %u\n",
167			    sd->alb_count, sd->alb_failed, sd->alb_pushed,
168			    sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
169			    sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
170			    sd->ttwu_wake_remote, sd->ttwu_move_affine,
171			    sd->ttwu_move_balance);
172		}
173		rcu_read_unlock();
174#endif
175	}
 
176	return 0;
177}
178
179/*
180 * This iterator needs some explanation.
181 * It returns 1 for the header position.
182 * This means 2 is cpu 0.
183 * In a hotplugged system some CPUs, including cpu 0, may be missing so we have
184 * to use cpumask_* to iterate over the CPUs.
185 */
186static void *schedstat_start(struct seq_file *file, loff_t *offset)
187{
188	unsigned long n = *offset;
189
190	if (n == 0)
191		return (void *) 1;
192
193	n--;
194
195	if (n > 0)
196		n = cpumask_next(n - 1, cpu_online_mask);
197	else
198		n = cpumask_first(cpu_online_mask);
199
200	*offset = n + 1;
201
202	if (n < nr_cpu_ids)
203		return (void *)(unsigned long)(n + 2);
204
205	return NULL;
206}
207
208static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
209{
210	(*offset)++;
211
212	return schedstat_start(file, offset);
213}
214
215static void schedstat_stop(struct seq_file *file, void *data)
216{
217}
218
219static const struct seq_operations schedstat_sops = {
220	.start = schedstat_start,
221	.next  = schedstat_next,
222	.stop  = schedstat_stop,
223	.show  = show_schedstat,
224};
225
 
 
 
 
 
 
 
 
 
 
 
 
226static int __init proc_schedstat_init(void)
227{
228	proc_create_seq("schedstat", 0, NULL, &schedstat_sops);
229	return 0;
230}
231subsys_initcall(proc_schedstat_init);