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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * /proc/schedstat implementation
4 */
5#include "sched.h"
6
7/*
8 * Current schedstat API version.
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
19 if (v == (void *)1) {
20 seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
21 seq_printf(seq, "timestamp %lu\n", jiffies);
22 } else {
23 struct rq *rq;
24#ifdef CONFIG_SMP
25 struct sched_domain *sd;
26 int dcount = 0;
27#endif
28 cpu = (unsigned long)(v - 2);
29 rq = cpu_rq(cpu);
30
31 /* runqueue-specific stats */
32 seq_printf(seq,
33 "cpu%d %u 0 %u %u %u %u %llu %llu %lu",
34 cpu, rq->yld_count,
35 rq->sched_count, rq->sched_goidle,
36 rq->ttwu_count, rq->ttwu_local,
37 rq->rq_cpu_time,
38 rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
39
40 seq_printf(seq, "\n");
41
42#ifdef CONFIG_SMP
43 /* domain-specific stats */
44 rcu_read_lock();
45 for_each_domain(cpu, sd) {
46 enum cpu_idle_type itype;
47
48 seq_printf(seq, "domain%d %*pb", dcount++,
49 cpumask_pr_args(sched_domain_span(sd)));
50 for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
51 itype++) {
52 seq_printf(seq, " %u %u %u %u %u %u %u %u",
53 sd->lb_count[itype],
54 sd->lb_balanced[itype],
55 sd->lb_failed[itype],
56 sd->lb_imbalance[itype],
57 sd->lb_gained[itype],
58 sd->lb_hot_gained[itype],
59 sd->lb_nobusyq[itype],
60 sd->lb_nobusyg[itype]);
61 }
62 seq_printf(seq,
63 " %u %u %u %u %u %u %u %u %u %u %u %u\n",
64 sd->alb_count, sd->alb_failed, sd->alb_pushed,
65 sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
66 sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
67 sd->ttwu_wake_remote, sd->ttwu_move_affine,
68 sd->ttwu_move_balance);
69 }
70 rcu_read_unlock();
71#endif
72 }
73 return 0;
74}
75
76/*
77 * This itererator needs some explanation.
78 * It returns 1 for the header position.
79 * This means 2 is cpu 0.
80 * In a hotplugged system some CPUs, including cpu 0, may be missing so we have
81 * to use cpumask_* to iterate over the CPUs.
82 */
83static void *schedstat_start(struct seq_file *file, loff_t *offset)
84{
85 unsigned long n = *offset;
86
87 if (n == 0)
88 return (void *) 1;
89
90 n--;
91
92 if (n > 0)
93 n = cpumask_next(n - 1, cpu_online_mask);
94 else
95 n = cpumask_first(cpu_online_mask);
96
97 *offset = n + 1;
98
99 if (n < nr_cpu_ids)
100 return (void *)(unsigned long)(n + 2);
101
102 return NULL;
103}
104
105static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
106{
107 (*offset)++;
108
109 return schedstat_start(file, offset);
110}
111
112static void schedstat_stop(struct seq_file *file, void *data)
113{
114}
115
116static const struct seq_operations schedstat_sops = {
117 .start = schedstat_start,
118 .next = schedstat_next,
119 .stop = schedstat_stop,
120 .show = show_schedstat,
121};
122
123static int schedstat_open(struct inode *inode, struct file *file)
124{
125 return seq_open(file, &schedstat_sops);
126}
127
128static const struct file_operations proc_schedstat_operations = {
129 .open = schedstat_open,
130 .read = seq_read,
131 .llseek = seq_lseek,
132 .release = seq_release,
133};
134
135static int __init proc_schedstat_init(void)
136{
137 proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
138
139 return 0;
140}
141subsys_initcall(proc_schedstat_init);
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 seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
25 seq_printf(seq, "timestamp %lu\n", jiffies);
26 for_each_online_cpu(cpu) {
27 struct rq *rq = cpu_rq(cpu);
28#ifdef CONFIG_SMP
29 struct sched_domain *sd;
30 int dcount = 0;
31#endif
32
33 /* runqueue-specific stats */
34 seq_printf(seq,
35 "cpu%d %u 0 %u %u %u %u %llu %llu %lu",
36 cpu, rq->yld_count,
37 rq->sched_count, rq->sched_goidle,
38 rq->ttwu_count, rq->ttwu_local,
39 rq->rq_cpu_time,
40 rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
41
42 seq_printf(seq, "\n");
43
44#ifdef CONFIG_SMP
45 /* domain-specific stats */
46 rcu_read_lock();
47 for_each_domain(cpu, sd) {
48 enum cpu_idle_type itype;
49
50 cpumask_scnprintf(mask_str, mask_len,
51 sched_domain_span(sd));
52 seq_printf(seq, "domain%d %s", dcount++, mask_str);
53 for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
54 itype++) {
55 seq_printf(seq, " %u %u %u %u %u %u %u %u",
56 sd->lb_count[itype],
57 sd->lb_balanced[itype],
58 sd->lb_failed[itype],
59 sd->lb_imbalance[itype],
60 sd->lb_gained[itype],
61 sd->lb_hot_gained[itype],
62 sd->lb_nobusyq[itype],
63 sd->lb_nobusyg[itype]);
64 }
65 seq_printf(seq,
66 " %u %u %u %u %u %u %u %u %u %u %u %u\n",
67 sd->alb_count, sd->alb_failed, sd->alb_pushed,
68 sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
69 sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
70 sd->ttwu_wake_remote, sd->ttwu_move_affine,
71 sd->ttwu_move_balance);
72 }
73 rcu_read_unlock();
74#endif
75 }
76 kfree(mask_str);
77 return 0;
78}
79
80static int schedstat_open(struct inode *inode, struct file *file)
81{
82 unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
83 char *buf = kmalloc(size, GFP_KERNEL);
84 struct seq_file *m;
85 int res;
86
87 if (!buf)
88 return -ENOMEM;
89 res = single_open(file, show_schedstat, NULL);
90 if (!res) {
91 m = file->private_data;
92 m->buf = buf;
93 m->size = size;
94 } else
95 kfree(buf);
96 return res;
97}
98
99static const struct file_operations proc_schedstat_operations = {
100 .open = schedstat_open,
101 .read = seq_read,
102 .llseek = seq_lseek,
103 .release = single_release,
104};
105
106static int __init proc_schedstat_init(void)
107{
108 proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
109 return 0;
110}
111module_init(proc_schedstat_init);