1  // SPDX-License-Identifier: GPL-2.0
2  #include <linux/cpumask.h>
3  #include <linux/fs.h>
4  #include <linux/init.h>
5  #include <linux/interrupt.h>
6  #include <linux/kernel_stat.h>
7  #include <linux/proc_fs.h>
8  #include <linux/sched.h>
9  #include <linux/sched/stat.h>
10  #include <linux/seq_file.h>
11  #include <linux/slab.h>
12  #include <linux/time.h>
13  #include <linux/time_namespace.h>
14  #include <linux/irqnr.h>
15  #include <linux/sched/cputime.h>
16  #include <linux/tick.h>
17  
18  #ifndef arch_irq_stat_cpu
19  #define arch_irq_stat_cpu(cpu) 0
20  #endif
21  #ifndef arch_irq_stat
22  #define arch_irq_stat() 0
23  #endif
24  
get_idle_time(struct kernel_cpustat * kcs,int cpu)25  u64 get_idle_time(struct kernel_cpustat *kcs, int cpu)
26  {
27  	u64 idle, idle_usecs = -1ULL;
28  
29  	if (cpu_online(cpu))
30  		idle_usecs = get_cpu_idle_time_us(cpu, NULL);
31  
32  	if (idle_usecs == -1ULL)
33  		/* !NO_HZ or cpu offline so we can rely on cpustat.idle */
34  		idle = kcs->cpustat[CPUTIME_IDLE];
35  	else
36  		idle = idle_usecs * NSEC_PER_USEC;
37  
38  	return idle;
39  }
40  
get_iowait_time(struct kernel_cpustat * kcs,int cpu)41  static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu)
42  {
43  	u64 iowait, iowait_usecs = -1ULL;
44  
45  	if (cpu_online(cpu))
46  		iowait_usecs = get_cpu_iowait_time_us(cpu, NULL);
47  
48  	if (iowait_usecs == -1ULL)
49  		/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
50  		iowait = kcs->cpustat[CPUTIME_IOWAIT];
51  	else
52  		iowait = iowait_usecs * NSEC_PER_USEC;
53  
54  	return iowait;
55  }
56  
show_irq_gap(struct seq_file * p,unsigned int gap)57  static void show_irq_gap(struct seq_file *p, unsigned int gap)
58  {
59  	static const char zeros[] = " 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0";
60  
61  	while (gap > 0) {
62  		unsigned int inc;
63  
64  		inc = min_t(unsigned int, gap, ARRAY_SIZE(zeros) / 2);
65  		seq_write(p, zeros, 2 * inc);
66  		gap -= inc;
67  	}
68  }
69  
show_all_irqs(struct seq_file * p)70  static void show_all_irqs(struct seq_file *p)
71  {
72  	unsigned int i, next = 0;
73  
74  	for_each_active_irq(i) {
75  		show_irq_gap(p, i - next);
76  		seq_put_decimal_ull(p, " ", kstat_irqs_usr(i));
77  		next = i + 1;
78  	}
79  	show_irq_gap(p, nr_irqs - next);
80  }
81  
show_stat(struct seq_file * p,void * v)82  static int show_stat(struct seq_file *p, void *v)
83  {
84  	int i, j;
85  	u64 user, nice, system, idle, iowait, irq, softirq, steal;
86  	u64 guest, guest_nice;
87  	u64 sum = 0;
88  	u64 sum_softirq = 0;
89  	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
90  	struct timespec64 boottime;
91  
92  	user = nice = system = idle = iowait =
93  		irq = softirq = steal = 0;
94  	guest = guest_nice = 0;
95  	getboottime64(&boottime);
96  	/* shift boot timestamp according to the timens offset */
97  	timens_sub_boottime(&boottime);
98  
99  	for_each_possible_cpu(i) {
100  		struct kernel_cpustat kcpustat;
101  		u64 *cpustat = kcpustat.cpustat;
102  
103  		kcpustat_cpu_fetch(&kcpustat, i);
104  
105  		user		+= cpustat[CPUTIME_USER];
106  		nice		+= cpustat[CPUTIME_NICE];
107  		system		+= cpustat[CPUTIME_SYSTEM];
108  		idle		+= get_idle_time(&kcpustat, i);
109  		iowait		+= get_iowait_time(&kcpustat, i);
110  		irq		+= cpustat[CPUTIME_IRQ];
111  		softirq		+= cpustat[CPUTIME_SOFTIRQ];
112  		steal		+= cpustat[CPUTIME_STEAL];
113  		guest		+= cpustat[CPUTIME_GUEST];
114  		guest_nice	+= cpustat[CPUTIME_GUEST_NICE];
115  		sum		+= kstat_cpu_irqs_sum(i);
116  		sum		+= arch_irq_stat_cpu(i);
117  
118  		for (j = 0; j < NR_SOFTIRQS; j++) {
119  			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
120  
121  			per_softirq_sums[j] += softirq_stat;
122  			sum_softirq += softirq_stat;
123  		}
124  	}
125  	sum += arch_irq_stat();
126  
127  	seq_put_decimal_ull(p, "cpu  ", nsec_to_clock_t(user));
128  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
129  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
130  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
131  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
132  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
133  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
134  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
135  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
136  	seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
137  	seq_putc(p, '\n');
138  
139  	for_each_online_cpu(i) {
140  		struct kernel_cpustat kcpustat;
141  		u64 *cpustat = kcpustat.cpustat;
142  
143  		kcpustat_cpu_fetch(&kcpustat, i);
144  
145  		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
146  		user		= cpustat[CPUTIME_USER];
147  		nice		= cpustat[CPUTIME_NICE];
148  		system		= cpustat[CPUTIME_SYSTEM];
149  		idle		= get_idle_time(&kcpustat, i);
150  		iowait		= get_iowait_time(&kcpustat, i);
151  		irq		= cpustat[CPUTIME_IRQ];
152  		softirq		= cpustat[CPUTIME_SOFTIRQ];
153  		steal		= cpustat[CPUTIME_STEAL];
154  		guest		= cpustat[CPUTIME_GUEST];
155  		guest_nice	= cpustat[CPUTIME_GUEST_NICE];
156  		seq_printf(p, "cpu%d", i);
157  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
158  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
159  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
160  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
161  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
162  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
163  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
164  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
165  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
166  		seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
167  		seq_putc(p, '\n');
168  	}
169  	seq_put_decimal_ull(p, "intr ", (unsigned long long)sum);
170  
171  	show_all_irqs(p);
172  
173  	seq_printf(p,
174  		"\nctxt %llu\n"
175  		"btime %llu\n"
176  		"processes %lu\n"
177  		"procs_running %u\n"
178  		"procs_blocked %u\n",
179  		nr_context_switches(),
180  		(unsigned long long)boottime.tv_sec,
181  		total_forks,
182  		nr_running(),
183  		nr_iowait());
184  
185  	seq_put_decimal_ull(p, "softirq ", (unsigned long long)sum_softirq);
186  
187  	for (i = 0; i < NR_SOFTIRQS; i++)
188  		seq_put_decimal_ull(p, " ", per_softirq_sums[i]);
189  	seq_putc(p, '\n');
190  
191  	return 0;
192  }
193  
stat_open(struct inode * inode,struct file * file)194  static int stat_open(struct inode *inode, struct file *file)
195  {
196  	unsigned int size = 1024 + 128 * num_online_cpus();
197  
198  	/* minimum size to display an interrupt count : 2 bytes */
199  	size += 2 * nr_irqs;
200  	return single_open_size(file, show_stat, NULL, size);
201  }
202  
203  static const struct proc_ops stat_proc_ops = {
204  	.proc_flags	= PROC_ENTRY_PERMANENT,
205  	.proc_open	= stat_open,
206  	.proc_read_iter	= seq_read_iter,
207  	.proc_lseek	= seq_lseek,
208  	.proc_release	= single_release,
209  };
210  
proc_stat_init(void)211  static int __init proc_stat_init(void)
212  {
213  	proc_create("stat", 0, NULL, &stat_proc_ops);
214  	return 0;
215  }
216  fs_initcall(proc_stat_init);
217