--- /dev/null
+Control Groupstats is inspired by the discussion at
+http://lkml.org/lkml/2007/4/11/187 and implements per cgroup statistics as
+suggested by Andrew Morton in http://lkml.org/lkml/2007/4/11/263.
+
+Per cgroup statistics infrastructure re-uses code from the taskstats
+interface. A new set of cgroup operations are registered with commands
+and attributes specific to cgroups. It should be very easy to
+extend per cgroup statistics, by adding members to the cgroupstats
+structure.
+
+The current model for cgroupstats is a pull, a push model (to post
+statistics on interesting events), should be very easy to add. Currently
+user space requests for statistics by passing the cgroup path.
+Statistics about the state of all the tasks in the cgroup is returned to
+user space.
+
+NOTE: We currently rely on delay accounting for extracting information
+about tasks blocked on I/O. If CONFIG_TASK_DELAY_ACCT is disabled, this
+information will not be available.
+
+To extract cgroup statistics a utility very similar to getdelays.c
+has been developed, the sample output of the utility is shown below
+
+~/balbir/cgroupstats # ./getdelays -C "/cgroup/a"
+sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
+~/balbir/cgroupstats # ./getdelays -C "/cgroup"
+sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2
header-y += coff.h
header-y += comstats.h
header-y += const.h
+header-y += cgroupstats.h
header-y += cycx_cfm.h
header-y += dlm_device.h
header-y += dlm_netlink.h
#include <linux/cpumask.h>
#include <linux/nodemask.h>
#include <linux/rcupdate.h>
+#include <linux/cgroupstats.h>
#ifdef CONFIG_CGROUPS
extern void cgroup_fork_callbacks(struct task_struct *p);
extern void cgroup_post_fork(struct task_struct *p);
extern void cgroup_exit(struct task_struct *p, int run_callbacks);
+extern int cgroupstats_build(struct cgroupstats *stats,
+ struct dentry *dentry);
extern struct file_operations proc_cgroup_operations;
static inline void cgroup_lock(void) {}
static inline void cgroup_unlock(void) {}
+static inline int cgroupstats_build(struct cgroupstats *stats,
+ struct dentry *dentry)
+{
+ return -EINVAL;
+}
#endif /* !CONFIG_CGROUPS */
--- /dev/null
+/* cgroupstats.h - exporting per-cgroup statistics
+ *
+ * Copyright IBM Corporation, 2007
+ * Author Balbir Singh <balbir@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#ifndef _LINUX_CGROUPSTATS_H
+#define _LINUX_CGROUPSTATS_H
+
+#include <linux/taskstats.h>
+
+/*
+ * Data shared between user space and kernel space on a per cgroup
+ * basis. This data is shared using taskstats.
+ *
+ * Most of these states are derived by looking at the task->state value
+ * For the nr_io_wait state, a flag in the delay accounting structure
+ * indicates that the task is waiting on IO
+ *
+ * Each member is aligned to a 8 byte boundary.
+ */
+struct cgroupstats {
+ __u64 nr_sleeping; /* Number of tasks sleeping */
+ __u64 nr_running; /* Number of tasks running */
+ __u64 nr_stopped; /* Number of tasks in stopped state */
+ __u64 nr_uninterruptible; /* Number of tasks in uninterruptible */
+ /* state */
+ __u64 nr_io_wait; /* Number of tasks waiting on IO */
+};
+
+/*
+ * Commands sent from userspace
+ * Not versioned. New commands should only be inserted at the enum's end
+ * prior to __CGROUPSTATS_CMD_MAX
+ */
+
+enum {
+ CGROUPSTATS_CMD_UNSPEC = __TASKSTATS_CMD_MAX, /* Reserved */
+ CGROUPSTATS_CMD_GET, /* user->kernel request/get-response */
+ CGROUPSTATS_CMD_NEW, /* kernel->user event */
+ __CGROUPSTATS_CMD_MAX,
+};
+
+#define CGROUPSTATS_CMD_MAX (__CGROUPSTATS_CMD_MAX - 1)
+
+enum {
+ CGROUPSTATS_TYPE_UNSPEC = 0, /* Reserved */
+ CGROUPSTATS_TYPE_CGROUP_STATS, /* contains name + stats */
+ __CGROUPSTATS_TYPE_MAX,
+};
+
+#define CGROUPSTATS_TYPE_MAX (__CGROUPSTATS_TYPE_MAX - 1)
+
+enum {
+ CGROUPSTATS_CMD_ATTR_UNSPEC = 0,
+ CGROUPSTATS_CMD_ATTR_FD,
+ __CGROUPSTATS_CMD_ATTR_MAX,
+};
+
+#define CGROUPSTATS_CMD_ATTR_MAX (__CGROUPSTATS_CMD_ATTR_MAX - 1)
+
+#endif /* _LINUX_CGROUPSTATS_H */
* Used to set current->delays->flags
*/
#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */
+#define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */
#ifdef CONFIG_TASK_DELAY_ACCT
extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
extern __u64 __delayacct_blkio_ticks(struct task_struct *);
+static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
+{
+ if (p->delays)
+ return (p->delays->flags & DELAYACCT_PF_BLKIO);
+ else
+ return 0;
+}
+
static inline void delayacct_set_flag(int flag)
{
if (current->delays)
static inline void delayacct_blkio_start(void)
{
+ delayacct_set_flag(DELAYACCT_PF_BLKIO);
if (current->delays)
__delayacct_blkio_start();
}
{
if (current->delays)
__delayacct_blkio_end();
+ delayacct_clear_flag(DELAYACCT_PF_BLKIO);
}
static inline int delayacct_add_tsk(struct taskstats *d,
{ return 0; }
static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
{ return 0; }
+static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
+{ return 0; }
#endif /* CONFIG_TASK_DELAY_ACCT */
#endif
#include <linux/string.h>
#include <linux/sort.h>
#include <linux/kmod.h>
+#include <linux/delayacct.h>
+#include <linux/cgroupstats.h>
+
#include <asm/atomic.h>
static DEFINE_MUTEX(cgroup_mutex);
return n;
}
+/**
+ * Build and fill cgroupstats so that taskstats can export it to user
+ * space.
+ *
+ * @stats: cgroupstats to fill information into
+ * @dentry: A dentry entry belonging to the cgroup for which stats have
+ * been requested.
+ */
+int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
+{
+ int ret = -EINVAL;
+ struct cgroup *cont;
+ struct cgroup_iter it;
+ struct task_struct *tsk;
+ /*
+ * Validate dentry by checking the superblock operations
+ */
+ if (dentry->d_sb->s_op != &cgroup_ops)
+ goto err;
+
+ ret = 0;
+ cont = dentry->d_fsdata;
+ rcu_read_lock();
+
+ cgroup_iter_start(cont, &it);
+ while ((tsk = cgroup_iter_next(cont, &it))) {
+ switch (tsk->state) {
+ case TASK_RUNNING:
+ stats->nr_running++;
+ break;
+ case TASK_INTERRUPTIBLE:
+ stats->nr_sleeping++;
+ break;
+ case TASK_UNINTERRUPTIBLE:
+ stats->nr_uninterruptible++;
+ break;
+ case TASK_STOPPED:
+ stats->nr_stopped++;
+ break;
+ default:
+ if (delayacct_is_task_waiting_on_io(tsk))
+ stats->nr_io_wait++;
+ break;
+ }
+ }
+ cgroup_iter_end(cont, &it);
+
+ rcu_read_unlock();
+err:
+ return ret;
+}
+
static int cmppid(const void *a, const void *b)
{
return *(pid_t *)a - *(pid_t *)b;
#include <linux/delayacct.h>
#include <linux/cpumask.h>
#include <linux/percpu.h>
+#include <linux/cgroupstats.h>
+#include <linux/cgroup.h>
+#include <linux/fs.h>
+#include <linux/file.h>
#include <net/genetlink.h>
#include <asm/atomic.h>
[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING },
[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
+static struct nla_policy
+cgroupstats_cmd_get_policy[CGROUPSTATS_CMD_ATTR_MAX+1] __read_mostly = {
+ [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },
+};
+
struct listener {
struct list_head list;
pid_t pid;
return NULL;
}
+static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
+{
+ int rc = 0;
+ struct sk_buff *rep_skb;
+ struct cgroupstats *stats;
+ struct nlattr *na;
+ size_t size;
+ u32 fd;
+ struct file *file;
+ int fput_needed;
+
+ na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
+ if (!na)
+ return -EINVAL;
+
+ fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
+ file = fget_light(fd, &fput_needed);
+ if (file) {
+ size = nla_total_size(sizeof(struct cgroupstats));
+
+ rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
+ size);
+ if (rc < 0)
+ goto err;
+
+ na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
+ sizeof(struct cgroupstats));
+ stats = nla_data(na);
+ memset(stats, 0, sizeof(*stats));
+
+ rc = cgroupstats_build(stats, file->f_dentry);
+ if (rc < 0)
+ goto err;
+
+ fput_light(file, fput_needed);
+ return send_reply(rep_skb, info->snd_pid);
+ }
+
+err:
+ if (file)
+ fput_light(file, fput_needed);
+ nlmsg_free(rep_skb);
+ return rc;
+}
+
static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
{
int rc = 0;
.policy = taskstats_cmd_get_policy,
};
+static struct genl_ops cgroupstats_ops = {
+ .cmd = CGROUPSTATS_CMD_GET,
+ .doit = cgroupstats_user_cmd,
+ .policy = cgroupstats_cmd_get_policy,
+};
+
/* Needed early in initialization */
void __init taskstats_init_early(void)
{
if (rc < 0)
goto err;
+ rc = genl_register_ops(&family, &cgroupstats_ops);
+ if (rc < 0)
+ goto err_cgroup_ops;
+
family_registered = 1;
+ printk("registered taskstats version %d\n", TASKSTATS_GENL_VERSION);
return 0;
+err_cgroup_ops:
+ genl_unregister_ops(&family, &taskstats_ops);
err:
genl_unregister_family(&family);
return rc;
projects / linux-2.6-omap-h63xx.git / commitdiff