diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/cpu_acct.c | 186 | ||||
| -rw-r--r-- | kernel/sched.c | 14 |
3 files changed, 198 insertions, 3 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index ea8c8a12e19..48a7fae0027 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_KEXEC) += kexec.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o obj-$(CONFIG_CPUSETS) += cpuset.o +obj-$(CONFIG_CGROUP_CPUACCT) += cpu_acct.o obj-$(CONFIG_IKCONFIG) += configs.o obj-$(CONFIG_STOP_MACHINE) += stop_machine.o obj-$(CONFIG_AUDIT) += audit.o auditfilter.o diff --git a/kernel/cpu_acct.c b/kernel/cpu_acct.c new file mode 100644 index 00000000000..731e47e7f16 --- /dev/null +++ b/kernel/cpu_acct.c @@ -0,0 +1,186 @@ +/* + * kernel/cpu_acct.c - CPU accounting cgroup subsystem + * + * Copyright (C) Google Inc, 2006 + * + * Developed by Paul Menage (menage@google.com) and Balbir Singh + * (balbir@in.ibm.com) + * + */ + +/* + * Example cgroup subsystem for reporting total CPU usage of tasks in a + * cgroup, along with percentage load over a time interval + */ + +#include <linux/module.h> +#include <linux/cgroup.h> +#include <linux/fs.h> +#include <linux/rcupdate.h> + +#include <asm/div64.h> + +struct cpuacct { + struct cgroup_subsys_state css; + spinlock_t lock; + /* total time used by this class */ + cputime64_t time; + + /* time when next load calculation occurs */ + u64 next_interval_check; + + /* time used in current period */ + cputime64_t current_interval_time; + + /* time used in last period */ + cputime64_t last_interval_time; +}; + +struct cgroup_subsys cpuacct_subsys; + +static inline struct cpuacct *cgroup_ca(struct cgroup *cont) +{ + return container_of(cgroup_subsys_state(cont, cpuacct_subsys_id), + struct cpuacct, css); +} + +static inline struct cpuacct *task_ca(struct task_struct *task) +{ + return container_of(task_subsys_state(task, cpuacct_subsys_id), + struct cpuacct, css); +} + +#define INTERVAL (HZ * 10) + +static inline u64 next_interval_boundary(u64 now) +{ + /* calculate the next interval boundary beyond the + * current time */ + do_div(now, INTERVAL); + return (now + 1) * INTERVAL; +} + +static struct cgroup_subsys_state *cpuacct_create( + struct cgroup_subsys *ss, struct cgroup *cont) +{ + struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); + + if (!ca) + return ERR_PTR(-ENOMEM); + spin_lock_init(&ca->lock); + ca->next_interval_check = next_interval_boundary(get_jiffies_64()); + return &ca->css; +} + +static void cpuacct_destroy(struct cgroup_subsys *ss, + struct cgroup *cont) +{ + kfree(cgroup_ca(cont)); +} + +/* Lazily update the load calculation if necessary. Called with ca locked */ +static void cpuusage_update(struct cpuacct *ca) +{ + u64 now = get_jiffies_64(); + + /* If we're not due for an update, return */ + if (ca->next_interval_check > now) + return; + + if (ca->next_interval_check <= (now - INTERVAL)) { + /* If it's been more than an interval since the last + * check, then catch up - the last interval must have + * been zero load */ + ca->last_interval_time = 0; + ca->next_interval_check = next_interval_boundary(now); + } else { + /* If a steal takes the last interval time negative, + * then we just ignore it */ + if ((s64)ca->current_interval_time > 0) + ca->last_interval_time = ca->current_interval_time; + else + ca->last_interval_time = 0; + ca->next_interval_check += INTERVAL; + } + ca->current_interval_time = 0; +} + +static u64 cpuusage_read(struct cgroup *cont, struct cftype *cft) +{ + struct cpuacct *ca = cgroup_ca(cont); + u64 time; + + spin_lock_irq(&ca->lock); + cpuusage_update(ca); + time = cputime64_to_jiffies64(ca->time); + spin_unlock_irq(&ca->lock); + + /* Convert 64-bit jiffies to seconds */ + time *= 1000; + do_div(time, HZ); + return time; +} + +static u64 load_read(struct cgroup *cont, struct cftype *cft) +{ + struct cpuacct *ca = cgroup_ca(cont); + u64 time; + + /* Find the time used in the previous interval */ + spin_lock_irq(&ca->lock); + cpuusage_update(ca); + time = cputime64_to_jiffies64(ca->last_interval_time); + spin_unlock_irq(&ca->lock); + + /* Convert time to a percentage, to give the load in the + * previous period */ + time *= 100; + do_div(time, INTERVAL); + + return time; +} + +static struct cftype files[] = { + { + .name = "usage", + .read_uint = cpuusage_read, + }, + { + .name = "load", + .read_uint = load_read, + } +}; + +static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cont) +{ + return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files)); +} + +void cpuacct_charge(struct task_struct *task, cputime_t cputime) +{ + + struct cpuacct *ca; + unsigned long flags; + + if (!cpuacct_subsys.active) + return; + rcu_read_lock(); + ca = task_ca(task); + if (ca) { + spin_lock_irqsave(&ca->lock, flags); + cpuusage_update(ca); + ca->time = cputime64_add(ca->time, cputime); + ca->current_interval_time = + cputime64_add(ca->current_interval_time, cputime); + spin_unlock_irqrestore(&ca->lock, flags); + } + rcu_read_unlock(); +} + +struct cgroup_subsys cpuacct_subsys = { + .name = "cpuacct", + .create = cpuacct_create, + .destroy = cpuacct_destroy, + .populate = cpuacct_populate, + .subsys_id = cpuacct_subsys_id, +}; diff --git a/kernel/sched.c b/kernel/sched.c index ed90be46fb3..72a2a16e221 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -51,6 +51,7 @@ #include <linux/cpu.h> #include <linux/cpuset.h> #include <linux/percpu.h> +#include <linux/cpu_acct.h> #include <linux/kthread.h> #include <linux/seq_file.h> #include <linux/sysctl.h> @@ -3307,9 +3308,13 @@ void account_user_time(struct task_struct *p, cputime_t cputime) { struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; cputime64_t tmp; + struct rq *rq = this_rq(); p->utime = cputime_add(p->utime, cputime); + if (p != rq->idle) + cpuacct_charge(p, cputime); + /* Add user time to cpustat. */ tmp = cputime_to_cputime64(cputime); if (TASK_NICE(p) > 0) @@ -3374,9 +3379,10 @@ void account_system_time(struct task_struct *p, int hardirq_offset, cpustat->irq = cputime64_add(cpustat->irq, tmp); else if (softirq_count()) cpustat->softirq = cputime64_add(cpustat->softirq, tmp); - else if (p != rq->idle) + else if (p != rq->idle) { cpustat->system = cputime64_add(cpustat->system, tmp); - else if (atomic_read(&rq->nr_iowait) > 0) + cpuacct_charge(p, cputime); + } else if (atomic_read(&rq->nr_iowait) > 0) cpustat->iowait = cputime64_add(cpustat->iowait, tmp); else cpustat->idle = cputime64_add(cpustat->idle, tmp); @@ -3412,8 +3418,10 @@ void account_steal_time(struct task_struct *p, cputime_t steal) cpustat->iowait = cputime64_add(cpustat->iowait, tmp); else cpustat->idle = cputime64_add(cpustat->idle, tmp); - } else + } else { cpustat->steal = cputime64_add(cpustat->steal, tmp); + cpuacct_charge(p, -tmp); + } } /* |