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2e76c24d LZ |
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> | |
b329fd5b | 9 | #include <linux/err.h> |
2e76c24d LZ |
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 | ||
d1712796 LZ |
20 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
21 | enum 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 */ | |
29 | struct 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 | ||
a7c6d554 TH |
36 | static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css) |
37 | { | |
38 | return css ? container_of(css, struct cpuacct, css) : NULL; | |
39 | } | |
40 | ||
d1712796 LZ |
41 | /* return cpu accounting group to which this task belongs */ |
42 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
43 | { | |
073219e9 | 44 | return css_ca(task_css(tsk, cpuacct_cgrp_id)); |
d1712796 LZ |
45 | } |
46 | ||
d1712796 LZ |
47 | static inline struct cpuacct *parent_ca(struct cpuacct *ca) |
48 | { | |
63876986 | 49 | return css_ca(css_parent(&ca->css)); |
d1712796 LZ |
50 | } |
51 | ||
7943e15a | 52 | static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage); |
14c6d3c8 LZ |
53 | static struct cpuacct root_cpuacct = { |
54 | .cpustat = &kernel_cpustat, | |
55 | .cpuusage = &root_cpuacct_cpuusage, | |
56 | }; | |
2e76c24d LZ |
57 | |
58 | /* create a new cpu accounting group */ | |
eb95419b TH |
59 | static struct cgroup_subsys_state * |
60 | cpuacct_css_alloc(struct cgroup_subsys_state *parent_css) | |
2e76c24d LZ |
61 | { |
62 | struct cpuacct *ca; | |
63 | ||
eb95419b | 64 | if (!parent_css) |
2e76c24d LZ |
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 | ||
81 | out_free_cpuusage: | |
82 | free_percpu(ca->cpuusage); | |
83 | out_free_ca: | |
84 | kfree(ca); | |
85 | out: | |
86 | return ERR_PTR(-ENOMEM); | |
87 | } | |
88 | ||
89 | /* destroy an existing cpu accounting group */ | |
eb95419b | 90 | static void cpuacct_css_free(struct cgroup_subsys_state *css) |
2e76c24d | 91 | { |
eb95419b | 92 | struct cpuacct *ca = css_ca(css); |
2e76c24d LZ |
93 | |
94 | free_percpu(ca->cpustat); | |
95 | free_percpu(ca->cpuusage); | |
96 | kfree(ca); | |
97 | } | |
98 | ||
99 | static 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 | ||
118 | static 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 */ | |
182446d0 | 135 | static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft) |
2e76c24d | 136 | { |
182446d0 | 137 | struct cpuacct *ca = css_ca(css); |
2e76c24d LZ |
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 | ||
182446d0 TH |
147 | static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft, |
148 | u64 reset) | |
2e76c24d | 149 | { |
182446d0 | 150 | struct cpuacct *ca = css_ca(css); |
2e76c24d LZ |
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 | ||
162 | out: | |
163 | return err; | |
164 | } | |
165 | ||
2da8ca82 | 166 | static int cpuacct_percpu_seq_show(struct seq_file *m, void *V) |
2e76c24d | 167 | { |
2da8ca82 | 168 | struct cpuacct *ca = css_ca(seq_css(m)); |
2e76c24d LZ |
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 | ||
180 | static const char * const cpuacct_stat_desc[] = { | |
181 | [CPUACCT_STAT_USER] = "user", | |
182 | [CPUACCT_STAT_SYSTEM] = "system", | |
183 | }; | |
184 | ||
2da8ca82 | 185 | static int cpuacct_stats_show(struct seq_file *sf, void *v) |
2e76c24d | 186 | { |
2da8ca82 | 187 | struct cpuacct *ca = css_ca(seq_css(sf)); |
2e76c24d LZ |
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); | |
44ffc75b | 197 | seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val); |
2e76c24d LZ |
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); | |
44ffc75b | 208 | seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val); |
2e76c24d LZ |
209 | |
210 | return 0; | |
211 | } | |
212 | ||
213 | static struct cftype files[] = { | |
214 | { | |
215 | .name = "usage", | |
216 | .read_u64 = cpuusage_read, | |
217 | .write_u64 = cpuusage_write, | |
218 | }, | |
219 | { | |
220 | .name = "usage_percpu", | |
2da8ca82 | 221 | .seq_show = cpuacct_percpu_seq_show, |
2e76c24d LZ |
222 | }, |
223 | { | |
224 | .name = "stat", | |
2da8ca82 | 225 | .seq_show = cpuacct_stats_show, |
2e76c24d LZ |
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 | */ | |
235 | void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
236 | { | |
237 | struct cpuacct *ca; | |
238 | int cpu; | |
239 | ||
2e76c24d LZ |
240 | cpu = task_cpu(tsk); |
241 | ||
242 | rcu_read_lock(); | |
243 | ||
244 | ca = task_ca(tsk); | |
245 | ||
543bc0e7 | 246 | while (true) { |
2e76c24d LZ |
247 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
248 | *cpuusage += cputime; | |
543bc0e7 LZ |
249 | |
250 | ca = parent_ca(ca); | |
251 | if (!ca) | |
252 | break; | |
2e76c24d LZ |
253 | } |
254 | ||
255 | rcu_read_unlock(); | |
256 | } | |
257 | ||
1966aaf7 LZ |
258 | /* |
259 | * Add user/system time to cpuacct. | |
260 | * | |
261 | * Note: it's the caller that updates the account of the root cgroup. | |
262 | */ | |
263 | void cpuacct_account_field(struct task_struct *p, int index, u64 val) | |
264 | { | |
265 | struct kernel_cpustat *kcpustat; | |
266 | struct cpuacct *ca; | |
267 | ||
1966aaf7 LZ |
268 | rcu_read_lock(); |
269 | ca = task_ca(p); | |
5f40d804 | 270 | while (ca != &root_cpuacct) { |
1966aaf7 LZ |
271 | kcpustat = this_cpu_ptr(ca->cpustat); |
272 | kcpustat->cpustat[index] += val; | |
63876986 | 273 | ca = parent_ca(ca); |
1966aaf7 LZ |
274 | } |
275 | rcu_read_unlock(); | |
276 | } | |
277 | ||
073219e9 | 278 | struct cgroup_subsys cpuacct_cgrp_subsys = { |
621e2de0 LZ |
279 | .css_alloc = cpuacct_css_alloc, |
280 | .css_free = cpuacct_css_free, | |
621e2de0 LZ |
281 | .base_cftypes = files, |
282 | .early_init = 1, | |
2e76c24d | 283 | }; |