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1#include <linux/cgroup.h>
2#include <linux/slab.h>
3#include <linux/percpu.h>
4#include <linux/spinlock.h>
5#include <linux/cpumask.h>
6#include <linux/seq_file.h>
7#include <linux/rcupdate.h>
8#include <linux/kernel_stat.h>
9#include <linux/err.h>
10
11#include "sched.h"
12
13/*
14 * CPU accounting code for task groups.
15 *
16 * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
17 * (balbir@in.ibm.com).
18 */
19
20/* Time spent by the tasks of the cpu accounting group executing in ... */
21enum cpuacct_stat_index {
22 CPUACCT_STAT_USER, /* ... user mode */
23 CPUACCT_STAT_SYSTEM, /* ... kernel mode */
24
25 CPUACCT_STAT_NSTATS,
26};
27
28/* track cpu usage of a group of tasks and its child groups */
29struct cpuacct {
30 struct cgroup_subsys_state css;
31 /* cpuusage holds pointer to a u64-type object on every cpu */
32 u64 __percpu *cpuusage;
33 struct kernel_cpustat __percpu *cpustat;
34};
35
36static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
37{
38 return css ? container_of(css, struct cpuacct, css) : NULL;
39}
40
41/* return cpu accounting group to which this task belongs */
42static inline struct cpuacct *task_ca(struct task_struct *tsk)
43{
44 return css_ca(task_css(tsk, cpuacct_cgrp_id));
45}
46
47static inline struct cpuacct *parent_ca(struct cpuacct *ca)
48{
49 return css_ca(css_parent(&ca->css));
50}
51
52static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);
53static struct cpuacct root_cpuacct = {
54 .cpustat = &kernel_cpustat,
55 .cpuusage = &root_cpuacct_cpuusage,
56};
57
58/* create a new cpu accounting group */
59static struct cgroup_subsys_state *
60cpuacct_css_alloc(struct cgroup_subsys_state *parent_css)
61{
62 struct cpuacct *ca;
63
64 if (!parent_css)
65 return &root_cpuacct.css;
66
67 ca = kzalloc(sizeof(*ca), GFP_KERNEL);
68 if (!ca)
69 goto out;
70
71 ca->cpuusage = alloc_percpu(u64);
72 if (!ca->cpuusage)
73 goto out_free_ca;
74
75 ca->cpustat = alloc_percpu(struct kernel_cpustat);
76 if (!ca->cpustat)
77 goto out_free_cpuusage;
78
79 return &ca->css;
80
81out_free_cpuusage:
82 free_percpu(ca->cpuusage);
83out_free_ca:
84 kfree(ca);
85out:
86 return ERR_PTR(-ENOMEM);
87}
88
89/* destroy an existing cpu accounting group */
90static void cpuacct_css_free(struct cgroup_subsys_state *css)
91{
92 struct cpuacct *ca = css_ca(css);
93
94 free_percpu(ca->cpustat);
95 free_percpu(ca->cpuusage);
96 kfree(ca);
97}
98
99static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
100{
101 u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
102 u64 data;
103
104#ifndef CONFIG_64BIT
105 /*
106 * Take rq->lock to make 64-bit read safe on 32-bit platforms.
107 */
108 raw_spin_lock_irq(&cpu_rq(cpu)->lock);
109 data = *cpuusage;
110 raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
111#else
112 data = *cpuusage;
113#endif
114
115 return data;
116}
117
118static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
119{
120 u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
121
122#ifndef CONFIG_64BIT
123 /*
124 * Take rq->lock to make 64-bit write safe on 32-bit platforms.
125 */
126 raw_spin_lock_irq(&cpu_rq(cpu)->lock);
127 *cpuusage = val;
128 raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
129#else
130 *cpuusage = val;
131#endif
132}
133
134/* return total cpu usage (in nanoseconds) of a group */
135static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)
136{
137 struct cpuacct *ca = css_ca(css);
138 u64 totalcpuusage = 0;
139 int i;
140
141 for_each_present_cpu(i)
142 totalcpuusage += cpuacct_cpuusage_read(ca, i);
143
144 return totalcpuusage;
145}
146
147static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
148 u64 reset)
149{
150 struct cpuacct *ca = css_ca(css);
151 int err = 0;
152 int i;
153
154 if (reset) {
155 err = -EINVAL;
156 goto out;
157 }
158
159 for_each_present_cpu(i)
160 cpuacct_cpuusage_write(ca, i, 0);
161
162out:
163 return err;
164}
165
166static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
167{
168 struct cpuacct *ca = css_ca(seq_css(m));
169 u64 percpu;
170 int i;
171
172 for_each_present_cpu(i) {
173 percpu = cpuacct_cpuusage_read(ca, i);
174 seq_printf(m, "%llu ", (unsigned long long) percpu);
175 }
176 seq_printf(m, "\n");
177 return 0;
178}
179
180static const char * const cpuacct_stat_desc[] = {
181 [CPUACCT_STAT_USER] = "user",
182 [CPUACCT_STAT_SYSTEM] = "system",
183};
184
185static int cpuacct_stats_show(struct seq_file *sf, void *v)
186{
187 struct cpuacct *ca = css_ca(seq_css(sf));
188 int cpu;
189 s64 val = 0;
190
191 for_each_online_cpu(cpu) {
192 struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
193 val += kcpustat->cpustat[CPUTIME_USER];
194 val += kcpustat->cpustat[CPUTIME_NICE];
195 }
196 val = cputime64_to_clock_t(val);
197 seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
198
199 val = 0;
200 for_each_online_cpu(cpu) {
201 struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
202 val += kcpustat->cpustat[CPUTIME_SYSTEM];
203 val += kcpustat->cpustat[CPUTIME_IRQ];
204 val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
205 }
206
207 val = cputime64_to_clock_t(val);
208 seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
209
210 return 0;
211}
212
213static struct cftype files[] = {
214 {
215 .name = "usage",
216 .read_u64 = cpuusage_read,
217 .write_u64 = cpuusage_write,
218 },
219 {
220 .name = "usage_percpu",
221 .seq_show = cpuacct_percpu_seq_show,
222 },
223 {
224 .name = "stat",
225 .seq_show = cpuacct_stats_show,
226 },
227 { } /* terminate */
228};
229
230/*
231 * charge this task's execution time to its accounting group.
232 *
233 * called with rq->lock held.
234 */
235void cpuacct_charge(struct task_struct *tsk, u64 cputime)
236{
237 struct cpuacct *ca;
238 int cpu;
239
240 cpu = task_cpu(tsk);
241
242 rcu_read_lock();
243
244 ca = task_ca(tsk);
245
246 while (true) {
247 u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
248 *cpuusage += cputime;
249
250 ca = parent_ca(ca);
251 if (!ca)
252 break;
253 }
254
255 rcu_read_unlock();
256}
257
258/*
259 * Add user/system time to cpuacct.
260 *
261 * Note: it's the caller that updates the account of the root cgroup.
262 */
263void cpuacct_account_field(struct task_struct *p, int index, u64 val)
264{
265 struct kernel_cpustat *kcpustat;
266 struct cpuacct *ca;
267
268 rcu_read_lock();
269 ca = task_ca(p);
270 while (ca != &root_cpuacct) {
271 kcpustat = this_cpu_ptr(ca->cpustat);
272 kcpustat->cpustat[index] += val;
273 ca = parent_ca(ca);
274 }
275 rcu_read_unlock();
276}
277
278struct cgroup_subsys cpuacct_cgrp_subsys = {
279 .css_alloc = cpuacct_css_alloc,
280 .css_free = cpuacct_css_free,
281 .base_cftypes = files,
282 .early_init = 1,
283};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * CPU accounting code for task groups.
4 *
5 * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
6 * (balbir@in.ibm.com).
7 */
8#include <asm/irq_regs.h>
9#include "sched.h"
10
11/* Time spent by the tasks of the CPU accounting group executing in ... */
12enum cpuacct_stat_index {
13 CPUACCT_STAT_USER, /* ... user mode */
14 CPUACCT_STAT_SYSTEM, /* ... kernel mode */
15
16 CPUACCT_STAT_NSTATS,
17};
18
19static const char * const cpuacct_stat_desc[] = {
20 [CPUACCT_STAT_USER] = "user",
21 [CPUACCT_STAT_SYSTEM] = "system",
22};
23
24struct cpuacct_usage {
25 u64 usages[CPUACCT_STAT_NSTATS];
26};
27
28/* track CPU usage of a group of tasks and its child groups */
29struct cpuacct {
30 struct cgroup_subsys_state css;
31 /* cpuusage holds pointer to a u64-type object on every CPU */
32 struct cpuacct_usage __percpu *cpuusage;
33 struct kernel_cpustat __percpu *cpustat;
34};
35
36static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
37{
38 return css ? container_of(css, struct cpuacct, css) : NULL;
39}
40
41/* Return CPU accounting group to which this task belongs */
42static inline struct cpuacct *task_ca(struct task_struct *tsk)
43{
44 return css_ca(task_css(tsk, cpuacct_cgrp_id));
45}
46
47static inline struct cpuacct *parent_ca(struct cpuacct *ca)
48{
49 return css_ca(ca->css.parent);
50}
51
52static DEFINE_PER_CPU(struct cpuacct_usage, root_cpuacct_cpuusage);
53static struct cpuacct root_cpuacct = {
54 .cpustat = &kernel_cpustat,
55 .cpuusage = &root_cpuacct_cpuusage,
56};
57
58/* Create a new CPU accounting group */
59static struct cgroup_subsys_state *
60cpuacct_css_alloc(struct cgroup_subsys_state *parent_css)
61{
62 struct cpuacct *ca;
63
64 if (!parent_css)
65 return &root_cpuacct.css;
66
67 ca = kzalloc(sizeof(*ca), GFP_KERNEL);
68 if (!ca)
69 goto out;
70
71 ca->cpuusage = alloc_percpu(struct cpuacct_usage);
72 if (!ca->cpuusage)
73 goto out_free_ca;
74
75 ca->cpustat = alloc_percpu(struct kernel_cpustat);
76 if (!ca->cpustat)
77 goto out_free_cpuusage;
78
79 return &ca->css;
80
81out_free_cpuusage:
82 free_percpu(ca->cpuusage);
83out_free_ca:
84 kfree(ca);
85out:
86 return ERR_PTR(-ENOMEM);
87}
88
89/* Destroy an existing CPU accounting group */
90static void cpuacct_css_free(struct cgroup_subsys_state *css)
91{
92 struct cpuacct *ca = css_ca(css);
93
94 free_percpu(ca->cpustat);
95 free_percpu(ca->cpuusage);
96 kfree(ca);
97}
98
99static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu,
100 enum cpuacct_stat_index index)
101{
102 struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
103 u64 data;
104
105 /*
106 * We allow index == CPUACCT_STAT_NSTATS here to read
107 * the sum of suages.
108 */
109 BUG_ON(index > CPUACCT_STAT_NSTATS);
110
111#ifndef CONFIG_64BIT
112 /*
113 * Take rq->lock to make 64-bit read safe on 32-bit platforms.
114 */
115 raw_spin_lock_irq(&cpu_rq(cpu)->lock);
116#endif
117
118 if (index == CPUACCT_STAT_NSTATS) {
119 int i = 0;
120
121 data = 0;
122 for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
123 data += cpuusage->usages[i];
124 } else {
125 data = cpuusage->usages[index];
126 }
127
128#ifndef CONFIG_64BIT
129 raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
130#endif
131
132 return data;
133}
134
135static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
136{
137 struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
138 int i;
139
140#ifndef CONFIG_64BIT
141 /*
142 * Take rq->lock to make 64-bit write safe on 32-bit platforms.
143 */
144 raw_spin_lock_irq(&cpu_rq(cpu)->lock);
145#endif
146
147 for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
148 cpuusage->usages[i] = val;
149
150#ifndef CONFIG_64BIT
151 raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
152#endif
153}
154
155/* Return total CPU usage (in nanoseconds) of a group */
156static u64 __cpuusage_read(struct cgroup_subsys_state *css,
157 enum cpuacct_stat_index index)
158{
159 struct cpuacct *ca = css_ca(css);
160 u64 totalcpuusage = 0;
161 int i;
162
163 for_each_possible_cpu(i)
164 totalcpuusage += cpuacct_cpuusage_read(ca, i, index);
165
166 return totalcpuusage;
167}
168
169static u64 cpuusage_user_read(struct cgroup_subsys_state *css,
170 struct cftype *cft)
171{
172 return __cpuusage_read(css, CPUACCT_STAT_USER);
173}
174
175static u64 cpuusage_sys_read(struct cgroup_subsys_state *css,
176 struct cftype *cft)
177{
178 return __cpuusage_read(css, CPUACCT_STAT_SYSTEM);
179}
180
181static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)
182{
183 return __cpuusage_read(css, CPUACCT_STAT_NSTATS);
184}
185
186static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
187 u64 val)
188{
189 struct cpuacct *ca = css_ca(css);
190 int cpu;
191
192 /*
193 * Only allow '0' here to do a reset.
194 */
195 if (val)
196 return -EINVAL;
197
198 for_each_possible_cpu(cpu)
199 cpuacct_cpuusage_write(ca, cpu, 0);
200
201 return 0;
202}
203
204static int __cpuacct_percpu_seq_show(struct seq_file *m,
205 enum cpuacct_stat_index index)
206{
207 struct cpuacct *ca = css_ca(seq_css(m));
208 u64 percpu;
209 int i;
210
211 for_each_possible_cpu(i) {
212 percpu = cpuacct_cpuusage_read(ca, i, index);
213 seq_printf(m, "%llu ", (unsigned long long) percpu);
214 }
215 seq_printf(m, "\n");
216 return 0;
217}
218
219static int cpuacct_percpu_user_seq_show(struct seq_file *m, void *V)
220{
221 return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_USER);
222}
223
224static int cpuacct_percpu_sys_seq_show(struct seq_file *m, void *V)
225{
226 return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_SYSTEM);
227}
228
229static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
230{
231 return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_NSTATS);
232}
233
234static int cpuacct_all_seq_show(struct seq_file *m, void *V)
235{
236 struct cpuacct *ca = css_ca(seq_css(m));
237 int index;
238 int cpu;
239
240 seq_puts(m, "cpu");
241 for (index = 0; index < CPUACCT_STAT_NSTATS; index++)
242 seq_printf(m, " %s", cpuacct_stat_desc[index]);
243 seq_puts(m, "\n");
244
245 for_each_possible_cpu(cpu) {
246 struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
247
248 seq_printf(m, "%d", cpu);
249
250 for (index = 0; index < CPUACCT_STAT_NSTATS; index++) {
251#ifndef CONFIG_64BIT
252 /*
253 * Take rq->lock to make 64-bit read safe on 32-bit
254 * platforms.
255 */
256 raw_spin_lock_irq(&cpu_rq(cpu)->lock);
257#endif
258
259 seq_printf(m, " %llu", cpuusage->usages[index]);
260
261#ifndef CONFIG_64BIT
262 raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
263#endif
264 }
265 seq_puts(m, "\n");
266 }
267 return 0;
268}
269
270static int cpuacct_stats_show(struct seq_file *sf, void *v)
271{
272 struct cpuacct *ca = css_ca(seq_css(sf));
273 s64 val[CPUACCT_STAT_NSTATS];
274 int cpu;
275 int stat;
276
277 memset(val, 0, sizeof(val));
278 for_each_possible_cpu(cpu) {
279 u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
280
281 val[CPUACCT_STAT_USER] += cpustat[CPUTIME_USER];
282 val[CPUACCT_STAT_USER] += cpustat[CPUTIME_NICE];
283 val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
284 val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
285 val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
286 }
287
288 for (stat = 0; stat < CPUACCT_STAT_NSTATS; stat++) {
289 seq_printf(sf, "%s %lld\n",
290 cpuacct_stat_desc[stat],
291 (long long)nsec_to_clock_t(val[stat]));
292 }
293
294 return 0;
295}
296
297static struct cftype files[] = {
298 {
299 .name = "usage",
300 .read_u64 = cpuusage_read,
301 .write_u64 = cpuusage_write,
302 },
303 {
304 .name = "usage_user",
305 .read_u64 = cpuusage_user_read,
306 },
307 {
308 .name = "usage_sys",
309 .read_u64 = cpuusage_sys_read,
310 },
311 {
312 .name = "usage_percpu",
313 .seq_show = cpuacct_percpu_seq_show,
314 },
315 {
316 .name = "usage_percpu_user",
317 .seq_show = cpuacct_percpu_user_seq_show,
318 },
319 {
320 .name = "usage_percpu_sys",
321 .seq_show = cpuacct_percpu_sys_seq_show,
322 },
323 {
324 .name = "usage_all",
325 .seq_show = cpuacct_all_seq_show,
326 },
327 {
328 .name = "stat",
329 .seq_show = cpuacct_stats_show,
330 },
331 { } /* terminate */
332};
333
334/*
335 * charge this task's execution time to its accounting group.
336 *
337 * called with rq->lock held.
338 */
339void cpuacct_charge(struct task_struct *tsk, u64 cputime)
340{
341 struct cpuacct *ca;
342 int index = CPUACCT_STAT_SYSTEM;
343 struct pt_regs *regs = get_irq_regs() ? : task_pt_regs(tsk);
344
345 if (regs && user_mode(regs))
346 index = CPUACCT_STAT_USER;
347
348 rcu_read_lock();
349
350 for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
351 __this_cpu_add(ca->cpuusage->usages[index], cputime);
352
353 rcu_read_unlock();
354}
355
356/*
357 * Add user/system time to cpuacct.
358 *
359 * Note: it's the caller that updates the account of the root cgroup.
360 */
361void cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
362{
363 struct cpuacct *ca;
364
365 rcu_read_lock();
366 for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca))
367 __this_cpu_add(ca->cpustat->cpustat[index], val);
368 rcu_read_unlock();
369}
370
371struct cgroup_subsys cpuacct_cgrp_subsys = {
372 .css_alloc = cpuacct_css_alloc,
373 .css_free = cpuacct_css_free,
374 .legacy_cftypes = files,
375 .early_init = true,
376};