diff options
| -rw-r--r-- | Documentation/accounting/cgroupstats.txt | 27 | ||||
| -rw-r--r-- | include/linux/Kbuild | 1 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 8 | ||||
| -rw-r--r-- | include/linux/cgroupstats.h | 70 | ||||
| -rw-r--r-- | include/linux/delayacct.h | 13 | ||||
| -rw-r--r-- | kernel/cgroup.c | 55 | ||||
| -rw-r--r-- | kernel/taskstats.c | 67 |
7 files changed, 241 insertions, 0 deletions
diff --git a/Documentation/accounting/cgroupstats.txt b/Documentation/accounting/cgroupstats.txt new file mode 100644 index 0000000..eda40fd --- /dev/null +++ b/Documentation/accounting/cgroupstats.txt @@ -0,0 +1,27 @@ +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 diff --git a/include/linux/Kbuild b/include/linux/Kbuild index 7ac8303..e3ffd14 100644 --- a/include/linux/Kbuild +++ b/include/linux/Kbuild @@ -47,6 +47,7 @@ header-y += coda_psdev.h 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 diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 9e9b7ef..8747932 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -13,6 +13,7 @@ #include <linux/cpumask.h> #include <linux/nodemask.h> #include <linux/rcupdate.h> +#include <linux/cgroupstats.h> #ifdef CONFIG_CGROUPS @@ -29,6 +30,8 @@ extern void cgroup_fork(struct task_struct *p); 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; @@ -313,6 +316,11 @@ static inline void cgroup_exit(struct task_struct *p, int callbacks) {} 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 */ diff --git a/include/linux/cgroupstats.h b/include/linux/cgroupstats.h new file mode 100644 index 0000000..4f53abf --- /dev/null +++ b/include/linux/cgroupstats.h @@ -0,0 +1,70 @@ +/* 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 */ diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 55d1ca5..ab94bc0 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -26,6 +26,7 @@ * 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 @@ -39,6 +40,14 @@ extern void __delayacct_blkio_end(void); 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) @@ -71,6 +80,7 @@ static inline void delayacct_tsk_free(struct task_struct *tsk) static inline void delayacct_blkio_start(void) { + delayacct_set_flag(DELAYACCT_PF_BLKIO); if (current->delays) __delayacct_blkio_start(); } @@ -79,6 +89,7 @@ static inline void delayacct_blkio_end(void) { if (current->delays) __delayacct_blkio_end(); + delayacct_clear_flag(DELAYACCT_PF_BLKIO); } static inline int delayacct_add_tsk(struct taskstats *d, @@ -116,6 +127,8 @@ 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 diff --git a/kernel/cgroup.c b/kernel/cgroup.c index d65a124..ca38db2 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -44,6 +44,9 @@ #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); @@ -1766,6 +1769,58 @@ static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cont) 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; diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 7d4d7f9..9f360f6 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -22,6 +22,10 @@ #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> @@ -49,6 +53,11 @@ __read_mostly = { [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; @@ -372,6 +381,51 @@ err: 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; @@ -522,6 +576,12 @@ static struct genl_ops taskstats_ops = { .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) { @@ -546,8 +606,15 @@ static int __init taskstats_init(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; |