[PATCH 4/6] Simple CPU accounting container subsystem

menage
2006-10-20T19:07:06Z

[-- Attachment #1: cpu_acct.patch --]
[-- Type: text/plain, Size: 5886 bytes --]

This demonstrates how to use the generic container subsystem for a
simple resource tracker that counts the total CPU time used by all
processes in a container, during the time that they're members of the
container.

Signed-off-by: Paul Menage <menage@google.com>

---
include/linux/cpu_acct.h | 14 +++++
init/Kconfig | 7 ++
kernel/Makefile | 1
kernel/cpu_acct.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++
kernel/sched.c | 6 ++
5 files changed, 138 insertions(+)

Index: container-2.6.19-rc2/include/linux/cpu_acct.h
===================================================================
--- /dev/null
+++ container-2.6.19-rc2/include/linux/cpu_acct.h
@@ -0,0 +1,14 @@
+
+#ifndef _LINUX_CPU_ACCT_H
+#define _LINUX_CPU_ACCT_H
+
+#include <linux/container.h>
+#include <asm/cputime.h>
+
+#ifdef CONFIG_CONTAINER_CPUACCT
+extern void cpuacct_charge(struct task_struct *, cputime_t cputime);
+#else
+static void inline cpuacct_charge(struct task_struct *p, cputime_t cputime) {}
+#endif
+
+#endif
Index: container-2.6.19-rc2/init/Kconfig
===================================================================
--- container-2.6.19-rc2.orig/init/Kconfig
+++ container-2.6.19-rc2/init/Kconfig
@@ -261,6 +261,13 @@ config CPUSETS_LEGACY_API
- /proc/<pid>/cpuset
- defaults cpuset subsystem to enabled

+config CONTAINER_CPUACCT
+ bool "Simple CPU accounting container subsystem"
+ select CONTAINERS
+ help
+ Provides a simple Resource Controller for monitoring the
+ total CPU consumed by the tasks in a container
+
config RELAY
bool "Kernel->user space relay support (formerly relayfs)"
help
Index: container-2.6.19-rc2/kernel/cpu_acct.c
===================================================================
--- /dev/null
+++ container-2.6.19-rc2/kernel/cpu_acct.c
@@ -0,0 +1,110 @@
+/*
+ * kernel/cpu_acct.c - CPU accounting container subsystem
+ *
+ * Copyright (C) Google Inc, 2006
+ *
+ */
+
+/*
+ * Container subsystem for reporting total CPU usage of tasks in a
+ * container.
+ */
+
+#include <linux/module.h>
+#include <linux/container.h>
+#include <linux/fs.h>
+#include <asm/div64.h>
+
+struct cpuacct {
+ spinlock_t lock;
+ cputime64_t time; // total time used by this class
+};
+
+static struct container_subsys cpuacct_subsys;
+static inline struct cpuacct *container_ca(struct container *cont)
+{
+ return (struct cpuacct *)cont->subsys[cpuacct_subsys.subsys_id];
+}
+
+static int cpuacct_create(struct container_subsys *ss, struct container *cont)
+{
+ struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
+ if (!ca) return -ENOMEM;
+ spin_lock_init(&ca->lock);
+ cont->subsys[cpuacct_subsys.subsys_id] = ca;
+ return 0;
+}
+
+static void cpuacct_destroy(struct container_subsys *ss,
+ struct container *cont)
+{
+ kfree(container_ca(cont));
+}
+
+static ssize_t cpuusage_read(struct container *cont,
+ struct cftype *cft,
+ struct file *file,
+ char __user *buf,
+ size_t nbytes, loff_t *ppos)
+{
+ struct cpuacct *ca = container_ca(cont);
+ cputime64_t time;
+ char usagebuf[64];
+ char *s = usagebuf;
+
+ spin_lock_irq(&ca->lock);
+ time = ca->time;
+ spin_unlock_irq(&ca->lock);
+
+ time *= 1000;
+ do_div(time, HZ);
+ s += sprintf(s, "%llu", (unsigned long long) time);
+
+ return simple_read_from_buffer(buf, nbytes, ppos, usagebuf, s - usagebuf);
+}
+
+static struct cftype cft_usage = {
+ .name = "cpu_usage",
+ .read = cpuusage_read,
+};
+
+static int cpuacct_populate(struct container_subsys *ss,
+ struct container *cont)
+{
+ return container_add_file(cont, &cft_usage);
+}
+
+
+void cpuacct_charge(struct task_struct *task, cputime_t cputime) {
+
+ struct cpuacct *ca;
+ struct container *cont;
+ unsigned long flags;
+
+ if (cpuacct_subsys.subsys_id < 0) return;
+ rcu_read_lock();
+ cont = rcu_dereference(task->container);
+ ca = container_ca(cont);
+ if (ca) {
+ spin_lock_irqsave(&ca->lock, flags);
+ ca->time = cputime64_add(ca->time, cputime);
+ spin_unlock_irqrestore(&ca->lock, flags);
+ }
+ rcu_read_unlock();
+}
+
+static struct container_subsys cpuacct_subsys = {
+ .name = "cpuacct",
+ .create = cpuacct_create,
+ .destroy = cpuacct_destroy,
+ .populate = cpuacct_populate,
+ .subsys_id = -1,
+};
+
+int __init init_cpuacct(void)
+{
+ int id = container_register_subsys(&cpuacct_subsys);
+ return id < 0 ? id : 0;
+}
+
+module_init(init_cpuacct)
Index: container-2.6.19-rc2/kernel/Makefile
===================================================================
--- container-2.6.19-rc2.orig/kernel/Makefile
+++ container-2.6.19-rc2/kernel/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_KEXEC) += kexec.o
obj-$(CONFIG_COMPAT) += compat.o
obj-$(CONFIG_CONTAINERS) += container.o
obj-$(CONFIG_CPUSETS) += cpuset.o
+obj-$(CONFIG_CONTAINER_CPUACCT) += cpu_acct.o
obj-$(CONFIG_IKCONFIG) += configs.o
obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
Index: container-2.6.19-rc2/kernel/sched.c
===================================================================
--- container-2.6.19-rc2.orig/kernel/sched.c
+++ container-2.6.19-rc2/kernel/sched.c
@@ -52,6 +52,7 @@
#include <linux/tsacct_kern.h>
#include <linux/kprobes.h>
#include <linux/delayacct.h>
+#include <linux/cpu_acct.h>
#include <asm/tlb.h>

#include <asm/unistd.h>
@@ -2977,6 +2978,8 @@ void account_user_time(struct task_struc

p->utime = cputime_add(p->utime, cputime);

+ cpuacct_charge(p, cputime);
+
/* Add user time to cpustat. */
tmp = cputime_to_cputime64(cputime);
if (TASK_NICE(p) > 0)
@@ -3000,6 +3003,9 @@ void account_system_time(struct task_str

p->stime = cputime_add(p->stime, cputime);

+ if (p != rq->idle)
+ cpuacct_charge(p, cputime);
+
/* Add system time to cpustat. */
tmp = cputime_to_cputime64(cputime);
if (hardirq_count() - hardirq_offset)

--