xref: /openbmc/linux/kernel/sched/stats.c (revision 293d5b43)
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 
15 static 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  */
83 static 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 
104 static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
105 {
106 	(*offset)++;
107 	return schedstat_start(file, offset);
108 }
109 
110 static void schedstat_stop(struct seq_file *file, void *data)
111 {
112 }
113 
114 static const struct seq_operations schedstat_sops = {
115 	.start = schedstat_start,
116 	.next  = schedstat_next,
117 	.stop  = schedstat_stop,
118 	.show  = show_schedstat,
119 };
120 
121 static int schedstat_open(struct inode *inode, struct file *file)
122 {
123 	return seq_open(file, &schedstat_sops);
124 }
125 
126 static 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 
133 static int __init proc_schedstat_init(void)
134 {
135 	proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
136 	return 0;
137 }
138 subsys_initcall(proc_schedstat_init);
139