2006-07-14 01:24:40 -06:00
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/*
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* taskstats.c - Export per-task statistics to userland
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*
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* Copyright (C) Shailabh Nagar, IBM Corp. 2006
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* (C) Balbir Singh, IBM Corp. 2006
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/taskstats_kern.h>
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2006-07-14 01:24:41 -06:00
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#include <linux/delayacct.h>
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2006-07-14 01:24:40 -06:00
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#include <net/genetlink.h>
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#include <asm/atomic.h>
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static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 };
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static int family_registered;
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kmem_cache_t *taskstats_cache;
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static struct genl_family family = {
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.id = GENL_ID_GENERATE,
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.name = TASKSTATS_GENL_NAME,
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.version = TASKSTATS_GENL_VERSION,
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.maxattr = TASKSTATS_CMD_ATTR_MAX,
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};
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static struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1]
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__read_mostly = {
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[TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 },
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[TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 },
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};
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static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
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void **replyp, size_t size)
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{
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struct sk_buff *skb;
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void *reply;
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/*
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* If new attributes are added, please revisit this allocation
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*/
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skb = nlmsg_new(size);
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if (!skb)
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return -ENOMEM;
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if (!info) {
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int seq = get_cpu_var(taskstats_seqnum)++;
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put_cpu_var(taskstats_seqnum);
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reply = genlmsg_put(skb, 0, seq,
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family.id, 0, 0,
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cmd, family.version);
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} else
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reply = genlmsg_put(skb, info->snd_pid, info->snd_seq,
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family.id, 0, 0,
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cmd, family.version);
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if (reply == NULL) {
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nlmsg_free(skb);
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return -EINVAL;
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}
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*skbp = skb;
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*replyp = reply;
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return 0;
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}
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static int send_reply(struct sk_buff *skb, pid_t pid, int event)
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{
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struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
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void *reply;
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int rc;
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reply = genlmsg_data(genlhdr);
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rc = genlmsg_end(skb, reply);
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if (rc < 0) {
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nlmsg_free(skb);
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return rc;
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}
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if (event == TASKSTATS_MSG_MULTICAST)
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return genlmsg_multicast(skb, pid, TASKSTATS_LISTEN_GROUP);
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return genlmsg_unicast(skb, pid);
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}
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static int fill_pid(pid_t pid, struct task_struct *pidtsk,
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struct taskstats *stats)
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{
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int rc;
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struct task_struct *tsk = pidtsk;
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if (!pidtsk) {
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read_lock(&tasklist_lock);
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tsk = find_task_by_pid(pid);
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if (!tsk) {
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read_unlock(&tasklist_lock);
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return -ESRCH;
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}
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get_task_struct(tsk);
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read_unlock(&tasklist_lock);
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} else
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get_task_struct(tsk);
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/*
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* Each accounting subsystem adds calls to its functions to
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* fill in relevant parts of struct taskstsats as follows
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*
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* rc = per-task-foo(stats, tsk);
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* if (rc)
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* goto err;
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*/
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2006-07-14 01:24:41 -06:00
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rc = delayacct_add_tsk(stats, tsk);
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stats->version = TASKSTATS_VERSION;
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/* Define err: label here if needed */
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2006-07-14 01:24:40 -06:00
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put_task_struct(tsk);
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return rc;
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}
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static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk,
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struct taskstats *stats)
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{
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struct task_struct *tsk, *first;
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2006-07-14 01:24:44 -06:00
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unsigned long flags;
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2006-07-14 01:24:40 -06:00
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2006-07-14 01:24:44 -06:00
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/*
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* Add additional stats from live tasks except zombie thread group
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* leaders who are already counted with the dead tasks
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*/
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2006-07-14 01:24:40 -06:00
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first = tgidtsk;
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if (!first) {
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2006-07-14 01:24:44 -06:00
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read_lock(&tasklist_lock);
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2006-07-14 01:24:40 -06:00
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first = find_task_by_pid(tgid);
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if (!first) {
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read_unlock(&tasklist_lock);
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return -ESRCH;
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}
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2006-07-14 01:24:44 -06:00
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get_task_struct(first);
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read_unlock(&tasklist_lock);
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} else
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get_task_struct(first);
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/* Start with stats from dead tasks */
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spin_lock_irqsave(&first->signal->stats_lock, flags);
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if (first->signal->stats)
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memcpy(stats, first->signal->stats, sizeof(*stats));
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spin_unlock_irqrestore(&first->signal->stats_lock, flags);
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2006-07-14 01:24:40 -06:00
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tsk = first;
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2006-07-14 01:24:44 -06:00
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read_lock(&tasklist_lock);
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2006-07-14 01:24:40 -06:00
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do {
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2006-07-14 01:24:44 -06:00
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if (tsk->exit_state == EXIT_ZOMBIE && thread_group_leader(tsk))
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continue;
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2006-07-14 01:24:40 -06:00
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/*
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2006-07-14 01:24:44 -06:00
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* Accounting subsystem can call its functions here to
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2006-07-14 01:24:40 -06:00
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* fill in relevant parts of struct taskstsats as follows
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*
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2006-07-14 01:24:44 -06:00
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* per-task-foo(stats, tsk);
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2006-07-14 01:24:40 -06:00
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*/
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2006-07-14 01:24:44 -06:00
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delayacct_add_tsk(stats, tsk);
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2006-07-14 01:24:41 -06:00
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2006-07-14 01:24:40 -06:00
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} while_each_thread(first, tsk);
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read_unlock(&tasklist_lock);
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2006-07-14 01:24:41 -06:00
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stats->version = TASKSTATS_VERSION;
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2006-07-14 01:24:40 -06:00
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/*
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2006-07-14 01:24:44 -06:00
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* Accounting subsytems can also add calls here to modify
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* fields of taskstats.
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2006-07-14 01:24:40 -06:00
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*/
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2006-07-14 01:24:44 -06:00
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return 0;
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}
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static void fill_tgid_exit(struct task_struct *tsk)
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{
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unsigned long flags;
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spin_lock_irqsave(&tsk->signal->stats_lock, flags);
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if (!tsk->signal->stats)
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goto ret;
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/*
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* Each accounting subsystem calls its functions here to
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* accumalate its per-task stats for tsk, into the per-tgid structure
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*
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* per-task-foo(tsk->signal->stats, tsk);
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*/
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delayacct_add_tsk(tsk->signal->stats, tsk);
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ret:
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spin_unlock_irqrestore(&tsk->signal->stats_lock, flags);
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return;
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2006-07-14 01:24:40 -06:00
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}
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2006-07-14 01:24:44 -06:00
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2006-07-14 01:24:40 -06:00
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static int taskstats_send_stats(struct sk_buff *skb, struct genl_info *info)
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{
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int rc = 0;
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struct sk_buff *rep_skb;
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struct taskstats stats;
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void *reply;
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size_t size;
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struct nlattr *na;
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/*
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* Size includes space for nested attributes
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*/
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size = nla_total_size(sizeof(u32)) +
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nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
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memset(&stats, 0, sizeof(stats));
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rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, &reply, size);
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if (rc < 0)
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return rc;
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if (info->attrs[TASKSTATS_CMD_ATTR_PID]) {
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u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
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rc = fill_pid(pid, NULL, &stats);
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if (rc < 0)
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goto err;
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na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
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NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid);
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NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
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stats);
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} else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
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u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
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rc = fill_tgid(tgid, NULL, &stats);
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if (rc < 0)
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goto err;
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na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
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NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid);
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NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
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stats);
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} else {
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rc = -EINVAL;
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goto err;
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}
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nla_nest_end(rep_skb, na);
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return send_reply(rep_skb, info->snd_pid, TASKSTATS_MSG_UNICAST);
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nla_put_failure:
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return genlmsg_cancel(rep_skb, reply);
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err:
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nlmsg_free(rep_skb);
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return rc;
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}
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/* Send pid data out on exit */
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void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats,
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2006-07-14 01:24:44 -06:00
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int group_dead)
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2006-07-14 01:24:40 -06:00
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{
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int rc;
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struct sk_buff *rep_skb;
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void *reply;
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size_t size;
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int is_thread_group;
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struct nlattr *na;
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2006-07-14 01:24:44 -06:00
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unsigned long flags;
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2006-07-14 01:24:40 -06:00
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if (!family_registered || !tidstats)
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return;
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2006-07-14 01:24:44 -06:00
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spin_lock_irqsave(&tsk->signal->stats_lock, flags);
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is_thread_group = tsk->signal->stats ? 1 : 0;
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spin_unlock_irqrestore(&tsk->signal->stats_lock, flags);
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2006-07-14 01:24:40 -06:00
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2006-07-14 01:24:44 -06:00
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rc = 0;
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2006-07-14 01:24:40 -06:00
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/*
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* Size includes space for nested attributes
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*/
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size = nla_total_size(sizeof(u32)) +
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nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
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if (is_thread_group)
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size = 2 * size; /* PID + STATS + TGID + STATS */
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rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size);
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if (rc < 0)
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goto ret;
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rc = fill_pid(tsk->pid, tsk, tidstats);
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if (rc < 0)
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goto err_skb;
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na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
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NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid);
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NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
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*tidstats);
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nla_nest_end(rep_skb, na);
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2006-07-14 01:24:44 -06:00
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if (!is_thread_group)
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goto send;
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2006-07-14 01:24:40 -06:00
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/*
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2006-07-14 01:24:44 -06:00
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* tsk has/had a thread group so fill the tsk->signal->stats structure
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* Doesn't matter if tsk is the leader or the last group member leaving
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2006-07-14 01:24:40 -06:00
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*/
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2006-07-14 01:24:44 -06:00
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fill_tgid_exit(tsk);
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if (!group_dead)
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goto send;
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2006-07-14 01:24:40 -06:00
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na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
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NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid);
|
2006-07-14 01:24:44 -06:00
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/* No locking needed for tsk->signal->stats since group is dead */
|
2006-07-14 01:24:40 -06:00
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NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
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2006-07-14 01:24:44 -06:00
|
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*tsk->signal->stats);
|
2006-07-14 01:24:40 -06:00
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nla_nest_end(rep_skb, na);
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2006-07-14 01:24:44 -06:00
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send:
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2006-07-14 01:24:40 -06:00
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send_reply(rep_skb, 0, TASKSTATS_MSG_MULTICAST);
|
2006-07-14 01:24:44 -06:00
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return;
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2006-07-14 01:24:40 -06:00
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nla_put_failure:
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genlmsg_cancel(rep_skb, reply);
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goto ret;
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err_skb:
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nlmsg_free(rep_skb);
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ret:
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return;
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}
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static struct genl_ops taskstats_ops = {
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|
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.cmd = TASKSTATS_CMD_GET,
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|
|
.doit = taskstats_send_stats,
|
|
|
|
.policy = taskstats_cmd_get_policy,
|
|
|
|
};
|
|
|
|
|
|
|
|
/* Needed early in initialization */
|
|
|
|
void __init taskstats_init_early(void)
|
|
|
|
{
|
|
|
|
taskstats_cache = kmem_cache_create("taskstats_cache",
|
|
|
|
sizeof(struct taskstats),
|
|
|
|
0, SLAB_PANIC, NULL, NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int __init taskstats_init(void)
|
|
|
|
{
|
|
|
|
int rc;
|
|
|
|
|
|
|
|
rc = genl_register_family(&family);
|
|
|
|
if (rc)
|
|
|
|
return rc;
|
|
|
|
|
|
|
|
rc = genl_register_ops(&family, &taskstats_ops);
|
|
|
|
if (rc < 0)
|
|
|
|
goto err;
|
|
|
|
|
|
|
|
family_registered = 1;
|
|
|
|
return 0;
|
|
|
|
err:
|
|
|
|
genl_unregister_family(&family);
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* late initcall ensures initialization of statistics collection
|
|
|
|
* mechanisms precedes initialization of the taskstats interface
|
|
|
|
*/
|
|
|
|
late_initcall(taskstats_init);
|