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>
14 * CPU accounting code for task groups.
16 * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
17 * (balbir@in.ibm.com).
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 */
28 enum cpuacct_usage_index {
29 CPUACCT_USAGE_USER, /* ... user mode */
30 CPUACCT_USAGE_SYSTEM, /* ... kernel mode */
32 CPUACCT_USAGE_NRUSAGE,
35 struct cpuacct_usage {
36 u64 usages[CPUACCT_USAGE_NRUSAGE];
39 /* track cpu usage of a group of tasks and its child groups */
41 struct cgroup_subsys_state css;
42 /* cpuusage holds pointer to a u64-type object on every cpu */
43 struct cpuacct_usage __percpu *cpuusage;
44 struct kernel_cpustat __percpu *cpustat;
47 static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
49 return css ? container_of(css, struct cpuacct, css) : NULL;
52 /* return cpu accounting group to which this task belongs */
53 static inline struct cpuacct *task_ca(struct task_struct *tsk)
55 return css_ca(task_css(tsk, cpuacct_cgrp_id));
58 static inline struct cpuacct *parent_ca(struct cpuacct *ca)
60 return css_ca(ca->css.parent);
63 static DEFINE_PER_CPU(struct cpuacct_usage, root_cpuacct_cpuusage);
64 static struct cpuacct root_cpuacct = {
65 .cpustat = &kernel_cpustat,
66 .cpuusage = &root_cpuacct_cpuusage,
69 /* create a new cpu accounting group */
70 static struct cgroup_subsys_state *
71 cpuacct_css_alloc(struct cgroup_subsys_state *parent_css)
76 return &root_cpuacct.css;
78 ca = kzalloc(sizeof(*ca), GFP_KERNEL);
82 ca->cpuusage = alloc_percpu(struct cpuacct_usage);
86 ca->cpustat = alloc_percpu(struct kernel_cpustat);
88 goto out_free_cpuusage;
93 free_percpu(ca->cpuusage);
97 return ERR_PTR(-ENOMEM);
100 /* destroy an existing cpu accounting group */
101 static void cpuacct_css_free(struct cgroup_subsys_state *css)
103 struct cpuacct *ca = css_ca(css);
105 free_percpu(ca->cpustat);
106 free_percpu(ca->cpuusage);
110 static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu,
111 enum cpuacct_usage_index index)
113 struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
117 * We allow index == CPUACCT_USAGE_NRUSAGE here to read
120 BUG_ON(index > CPUACCT_USAGE_NRUSAGE);
124 * Take rq->lock to make 64-bit read safe on 32-bit platforms.
126 raw_spin_lock_irq(&cpu_rq(cpu)->lock);
129 if (index == CPUACCT_USAGE_NRUSAGE) {
133 for (i = 0; i < CPUACCT_USAGE_NRUSAGE; i++)
134 data += cpuusage->usages[i];
136 data = cpuusage->usages[index];
140 raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
146 static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
148 struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
153 * Take rq->lock to make 64-bit write safe on 32-bit platforms.
155 raw_spin_lock_irq(&cpu_rq(cpu)->lock);
158 for (i = 0; i < CPUACCT_USAGE_NRUSAGE; i++)
159 cpuusage->usages[i] = val;
162 raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
166 /* return total cpu usage (in nanoseconds) of a group */
167 static u64 __cpuusage_read(struct cgroup_subsys_state *css,
168 enum cpuacct_usage_index index)
170 struct cpuacct *ca = css_ca(css);
171 u64 totalcpuusage = 0;
174 for_each_possible_cpu(i)
175 totalcpuusage += cpuacct_cpuusage_read(ca, i, index);
177 return totalcpuusage;
180 static u64 cpuusage_user_read(struct cgroup_subsys_state *css,
183 return __cpuusage_read(css, CPUACCT_USAGE_USER);
186 static u64 cpuusage_sys_read(struct cgroup_subsys_state *css,
189 return __cpuusage_read(css, CPUACCT_USAGE_SYSTEM);
192 static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)
194 return __cpuusage_read(css, CPUACCT_USAGE_NRUSAGE);
197 static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
200 struct cpuacct *ca = css_ca(css);
204 * Only allow '0' here to do a reset.
209 for_each_possible_cpu(cpu)
210 cpuacct_cpuusage_write(ca, cpu, 0);
215 static int __cpuacct_percpu_seq_show(struct seq_file *m,
216 enum cpuacct_usage_index index)
218 struct cpuacct *ca = css_ca(seq_css(m));
222 for_each_possible_cpu(i) {
223 percpu = cpuacct_cpuusage_read(ca, i, index);
224 seq_printf(m, "%llu ", (unsigned long long) percpu);
230 static int cpuacct_percpu_user_seq_show(struct seq_file *m, void *V)
232 return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_USER);
235 static int cpuacct_percpu_sys_seq_show(struct seq_file *m, void *V)
237 return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_SYSTEM);
240 static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
242 return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_NRUSAGE);
245 static const char * const cpuacct_stat_desc[] = {
246 [CPUACCT_STAT_USER] = "user",
247 [CPUACCT_STAT_SYSTEM] = "system",
250 static int cpuacct_stats_show(struct seq_file *sf, void *v)
252 struct cpuacct *ca = css_ca(seq_css(sf));
256 for_each_possible_cpu(cpu) {
257 struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
258 val += kcpustat->cpustat[CPUTIME_USER];
259 val += kcpustat->cpustat[CPUTIME_NICE];
261 val = cputime64_to_clock_t(val);
262 seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
265 for_each_possible_cpu(cpu) {
266 struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
267 val += kcpustat->cpustat[CPUTIME_SYSTEM];
268 val += kcpustat->cpustat[CPUTIME_IRQ];
269 val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
272 val = cputime64_to_clock_t(val);
273 seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
278 static struct cftype files[] = {
281 .read_u64 = cpuusage_read,
282 .write_u64 = cpuusage_write,
285 .name = "usage_user",
286 .read_u64 = cpuusage_user_read,
290 .read_u64 = cpuusage_sys_read,
293 .name = "usage_percpu",
294 .seq_show = cpuacct_percpu_seq_show,
297 .name = "usage_percpu_user",
298 .seq_show = cpuacct_percpu_user_seq_show,
301 .name = "usage_percpu_sys",
302 .seq_show = cpuacct_percpu_sys_seq_show,
306 .seq_show = cpuacct_stats_show,
312 * charge this task's execution time to its accounting group.
314 * called with rq->lock held.
316 void cpuacct_charge(struct task_struct *tsk, u64 cputime)
319 int index = CPUACCT_USAGE_SYSTEM;
320 struct pt_regs *regs = task_pt_regs(tsk);
322 if (regs && user_mode(regs))
323 index = CPUACCT_USAGE_USER;
327 for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
328 this_cpu_ptr(ca->cpuusage)->usages[index] += cputime;
334 * Add user/system time to cpuacct.
336 * Note: it's the caller that updates the account of the root cgroup.
338 void cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
343 for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca))
344 this_cpu_ptr(ca->cpustat)->cpustat[index] += val;
348 struct cgroup_subsys cpuacct_cgrp_subsys = {
349 .css_alloc = cpuacct_css_alloc,
350 .css_free = cpuacct_css_free,
351 .legacy_cftypes = files,