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
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	return NULL;
102}
103
104static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
105{
106	(*offset)++;
107	return schedstat_start(file, offset);
108}
109
110static void schedstat_stop(struct seq_file *file, void *data)
111{
112}
113
114static const struct seq_operations schedstat_sops = {
115	.start = schedstat_start,
116	.next  = schedstat_next,
117	.stop  = schedstat_stop,
118	.show  = show_schedstat,
119};
120
121static int schedstat_open(struct inode *inode, struct file *file)
122{
123	return seq_open(file, &schedstat_sops);
124}
125
126static const struct file_operations proc_schedstat_operations = {
127	.open    = schedstat_open,
128	.read    = seq_read,
129	.llseek  = seq_lseek,
130	.release = seq_release,
131};
132
133static int __init proc_schedstat_init(void)
134{
135	proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
136	return 0;
137}
138subsys_initcall(proc_schedstat_init);
139