linux/kernel/sched/cpuacct.c
Li Zefan 2e76c24d72 sched: Split cpuacct code out of core.c
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5155366F.5060404@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10 13:54:15 +02:00

228 lines
4.5 KiB
C

#include <linux/cgroup.h>
#include <linux/slab.h>
#include <linux/percpu.h>
#include <linux/spinlock.h>
#include <linux/cpumask.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <linux/kernel_stat.h>
#include "sched.h"
/*
* CPU accounting code for task groups.
*
* Based on the work by Paul Menage (menage@google.com) and Balbir Singh
* (balbir@in.ibm.com).
*/
struct cpuacct root_cpuacct;
/* create a new cpu accounting group */
static struct cgroup_subsys_state *cpuacct_css_alloc(struct cgroup *cgrp)
{
struct cpuacct *ca;
if (!cgrp->parent)
return &root_cpuacct.css;
ca = kzalloc(sizeof(*ca), GFP_KERNEL);
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 *cgrp)
{
struct cpuacct *ca = cgroup_ca(cgrp);
free_percpu(ca->cpustat);
free_percpu(ca->cpuusage);
kfree(ca);
}
static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
{
u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
u64 data;
#ifndef CONFIG_64BIT
/*
* Take rq->lock to make 64-bit read safe on 32-bit platforms.
*/
raw_spin_lock_irq(&cpu_rq(cpu)->lock);
data = *cpuusage;
raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
#else
data = *cpuusage;
#endif
return data;
}
static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
{
u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
#ifndef CONFIG_64BIT
/*
* Take rq->lock to make 64-bit write safe on 32-bit platforms.
*/
raw_spin_lock_irq(&cpu_rq(cpu)->lock);
*cpuusage = val;
raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
#else
*cpuusage = val;
#endif
}
/* return total cpu usage (in nanoseconds) of a group */
static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
{
struct cpuacct *ca = cgroup_ca(cgrp);
u64 totalcpuusage = 0;
int i;
for_each_present_cpu(i)
totalcpuusage += cpuacct_cpuusage_read(ca, i);
return totalcpuusage;
}
static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
u64 reset)
{
struct cpuacct *ca = cgroup_ca(cgrp);
int err = 0;
int i;
if (reset) {
err = -EINVAL;
goto out;
}
for_each_present_cpu(i)
cpuacct_cpuusage_write(ca, i, 0);
out:
return err;
}
static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
struct seq_file *m)
{
struct cpuacct *ca = cgroup_ca(cgroup);
u64 percpu;
int i;
for_each_present_cpu(i) {
percpu = cpuacct_cpuusage_read(ca, i);
seq_printf(m, "%llu ", (unsigned long long) percpu);
}
seq_printf(m, "\n");
return 0;
}
static const char * const cpuacct_stat_desc[] = {
[CPUACCT_STAT_USER] = "user",
[CPUACCT_STAT_SYSTEM] = "system",
};
static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
struct cgroup_map_cb *cb)
{
struct cpuacct *ca = cgroup_ca(cgrp);
int cpu;
s64 val = 0;
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
val += kcpustat->cpustat[CPUTIME_USER];
val += kcpustat->cpustat[CPUTIME_NICE];
}
val = cputime64_to_clock_t(val);
cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val);
val = 0;
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
val += kcpustat->cpustat[CPUTIME_SYSTEM];
val += kcpustat->cpustat[CPUTIME_IRQ];
val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
}
val = cputime64_to_clock_t(val);
cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
return 0;
}
static struct cftype files[] = {
{
.name = "usage",
.read_u64 = cpuusage_read,
.write_u64 = cpuusage_write,
},
{
.name = "usage_percpu",
.read_seq_string = cpuacct_percpu_seq_read,
},
{
.name = "stat",
.read_map = 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)
{
struct cpuacct *ca;
int cpu;
if (unlikely(!cpuacct_subsys.active))
return;
cpu = task_cpu(tsk);
rcu_read_lock();
ca = task_ca(tsk);
for (; ca; ca = parent_ca(ca)) {
u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
*cpuusage += cputime;
}
rcu_read_unlock();
}
struct cgroup_subsys cpuacct_subsys = {
.name = "cpuacct",
.css_alloc = cpuacct_css_alloc,
.css_free = cpuacct_css_free,
.subsys_id = cpuacct_subsys_id,
.base_cftypes = files,
};