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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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/* * CPU accounting code for task groups. * * Based on the work by Paul Menage (menage@google.com) and Balbir Singh * (balbir@in.ibm.com). */#include <linux/sched/cputime.h>#include "sched.h"
/* Time spent by the tasks of the CPU accounting group executing in ... */enum cpuacct_stat_index { CPUACCT_STAT_USER, /* ... user mode */ CPUACCT_STAT_SYSTEM, /* ... kernel mode */
CPUACCT_STAT_NSTATS,};
static const char * const cpuacct_stat_desc[] = { [CPUACCT_STAT_USER] = "user", [CPUACCT_STAT_SYSTEM] = "system",};
/* track CPU usage of a group of tasks and its child groups */struct cpuacct { struct cgroup_subsys_state css; /* cpuusage holds pointer to a u64-type object on every CPU */ u64 __percpu *cpuusage; struct kernel_cpustat __percpu *cpustat;};
static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css){ return css ? container_of(css, struct cpuacct, css) : NULL;}
/* Return CPU accounting group to which this task belongs */static inline struct cpuacct *task_ca(struct task_struct *tsk){ return css_ca(task_css(tsk, cpuacct_cgrp_id));}
static inline struct cpuacct *parent_ca(struct cpuacct *ca){ return css_ca(ca->css.parent);}
static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);static struct cpuacct root_cpuacct = { .cpustat = &kernel_cpustat, .cpuusage = &root_cpuacct_cpuusage,};
/* Create a new CPU accounting group */static struct cgroup_subsys_state *cpuacct_css_alloc(struct cgroup_subsys_state *parent_css){ struct cpuacct *ca;
if (!parent_css) return &root_cpuacct.css;
ca = kzalloc_obj(*ca); if (!ca) goto out;
ca->cpuusage = alloc_percpu(u64); if (!ca->cpuusage) goto out_free_ca;
ca->cpustat = alloc_percpu(struct kernel_cpustat); if (!ca->cpustat) goto out_free_cpuusage;
return &ca->css;
out_free_cpuusage: free_percpu(ca->cpuusage);out_free_ca: kfree(ca);out: return ERR_PTR(-ENOMEM);}
/* Destroy an existing CPU accounting group */static void cpuacct_css_free(struct cgroup_subsys_state *css){ struct cpuacct *ca = css_ca(css);
free_percpu(ca->cpustat); free_percpu(ca->cpuusage); kfree(ca);}
static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu, enum cpuacct_stat_index index){ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat; u64 data;
/* * We allow index == CPUACCT_STAT_NSTATS here to read * the sum of usages. */ if (WARN_ON_ONCE(index > CPUACCT_STAT_NSTATS)) return 0;
#ifndef CONFIG_64BIT /* * Take rq->lock to make 64-bit read safe on 32-bit platforms. */ raw_spin_rq_lock_irq(cpu_rq(cpu));#endif
switch (index) { case CPUACCT_STAT_USER: data = cpustat[CPUTIME_USER] + cpustat[CPUTIME_NICE]; break; case CPUACCT_STAT_SYSTEM: data = cpustat[CPUTIME_SYSTEM] + cpustat[CPUTIME_IRQ] + cpustat[CPUTIME_SOFTIRQ]; break; case CPUACCT_STAT_NSTATS: data = *cpuusage; break; }
#ifndef CONFIG_64BIT raw_spin_rq_unlock_irq(cpu_rq(cpu));#endif
return data;}
static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu){ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
/* Don't allow to reset global kernel_cpustat */ if (ca == &root_cpuacct) return;
#ifndef CONFIG_64BIT /* * Take rq->lock to make 64-bit write safe on 32-bit platforms. */ raw_spin_rq_lock_irq(cpu_rq(cpu));#endif *cpuusage = 0; cpustat[CPUTIME_USER] = cpustat[CPUTIME_NICE] = 0; cpustat[CPUTIME_SYSTEM] = cpustat[CPUTIME_IRQ] = 0; cpustat[CPUTIME_SOFTIRQ] = 0;
#ifndef CONFIG_64BIT raw_spin_rq_unlock_irq(cpu_rq(cpu));#endif}
/* Return total CPU usage (in nanoseconds) of a group */static u64 __cpuusage_read(struct cgroup_subsys_state *css, enum cpuacct_stat_index index){ struct cpuacct *ca = css_ca(css); u64 totalcpuusage = 0; int i;
for_each_possible_cpu(i) totalcpuusage += cpuacct_cpuusage_read(ca, i, index);
return totalcpuusage;}
static u64 cpuusage_user_read(struct cgroup_subsys_state *css, struct cftype *cft){ return __cpuusage_read(css, CPUACCT_STAT_USER);}
static u64 cpuusage_sys_read(struct cgroup_subsys_state *css, struct cftype *cft){ return __cpuusage_read(css, CPUACCT_STAT_SYSTEM);}
static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft){ return __cpuusage_read(css, CPUACCT_STAT_NSTATS);}
static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft, u64 val){ struct cpuacct *ca = css_ca(css); int cpu;
/* * Only allow '0' here to do a reset. */ if (val) return -EINVAL;
for_each_possible_cpu(cpu) cpuacct_cpuusage_write(ca, cpu);
return 0;}
static int __cpuacct_percpu_seq_show(struct seq_file *m, enum cpuacct_stat_index index){ struct cpuacct *ca = css_ca(seq_css(m)); u64 percpu; int i;
for_each_possible_cpu(i) { percpu = cpuacct_cpuusage_read(ca, i, index); seq_printf(m, "%llu ", (unsigned long long) percpu); } seq_printf(m, "\n"); return 0;}
static int cpuacct_percpu_user_seq_show(struct seq_file *m, void *V){ return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_USER);}
static int cpuacct_percpu_sys_seq_show(struct seq_file *m, void *V){ return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_SYSTEM);}
static int cpuacct_percpu_seq_show(struct seq_file *m, void *V){ return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_NSTATS);}
static int cpuacct_all_seq_show(struct seq_file *m, void *V){ struct cpuacct *ca = css_ca(seq_css(m)); int index; int cpu;
seq_puts(m, "cpu"); for (index = 0; index < CPUACCT_STAT_NSTATS; index++) seq_printf(m, " %s", cpuacct_stat_desc[index]); seq_puts(m, "\n");
for_each_possible_cpu(cpu) { seq_printf(m, "%d", cpu); for (index = 0; index < CPUACCT_STAT_NSTATS; index++) seq_printf(m, " %llu", cpuacct_cpuusage_read(ca, cpu, index)); seq_puts(m, "\n"); } return 0;}
static int cpuacct_stats_show(struct seq_file *sf, void *v){ struct cpuacct *ca = css_ca(seq_css(sf)); struct task_cputime cputime; u64 val[CPUACCT_STAT_NSTATS]; int cpu; int stat;
memset(&cputime, 0, sizeof(cputime)); for_each_possible_cpu(cpu) { u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
cputime.utime += cpustat[CPUTIME_USER]; cputime.utime += cpustat[CPUTIME_NICE]; cputime.stime += cpustat[CPUTIME_SYSTEM]; cputime.stime += cpustat[CPUTIME_IRQ]; cputime.stime += cpustat[CPUTIME_SOFTIRQ];
cputime.sum_exec_runtime += *per_cpu_ptr(ca->cpuusage, cpu); }
cputime_adjust(&cputime, &seq_css(sf)->cgroup->prev_cputime, &val[CPUACCT_STAT_USER], &val[CPUACCT_STAT_SYSTEM]);
for (stat = 0; stat < CPUACCT_STAT_NSTATS; stat++) { seq_printf(sf, "%s %llu\n", cpuacct_stat_desc[stat], nsec_to_clock_t(val[stat])); }
return 0;}
static struct cftype files[] = { { .name = "usage", .read_u64 = cpuusage_read, .write_u64 = cpuusage_write, }, { .name = "usage_user", .read_u64 = cpuusage_user_read, }, { .name = "usage_sys", .read_u64 = cpuusage_sys_read, }, { .name = "usage_percpu", .seq_show = cpuacct_percpu_seq_show, }, { .name = "usage_percpu_user", .seq_show = cpuacct_percpu_user_seq_show, }, { .name = "usage_percpu_sys", .seq_show = cpuacct_percpu_sys_seq_show, }, { .name = "usage_all", .seq_show = cpuacct_all_seq_show, }, { .name = "stat", .seq_show = cpuacct_stats_show, }, { } /* terminate */};
/* * charge this task's execution time to its accounting group. * * called with rq->lock held. */void cpuacct_charge(struct task_struct *tsk, u64 cputime){ unsigned int cpu = task_cpu(tsk); struct cpuacct *ca;
lockdep_assert_rq_held(cpu_rq(cpu));
for (ca = task_ca(tsk); ca; ca = parent_ca(ca)) *per_cpu_ptr(ca->cpuusage, cpu) += cputime;}
/* * Add user/system time to cpuacct. * * Note: it's the caller that updates the account of the root cgroup. */void cpuacct_account_field(struct task_struct *tsk, int index, u64 val){ struct cpuacct *ca;
for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca)) __this_cpu_add(ca->cpustat->cpustat[index], val);}
struct cgroup_subsys cpuacct_cgrp_subsys = { .css_alloc = cpuacct_css_alloc, .css_free = cpuacct_css_free, .legacy_cftypes = files, .early_init = true,};