diff options
Diffstat (limited to 'kernel/taskstats.c')
| -rw-r--r-- | kernel/taskstats.c | 98 |
1 files changed, 66 insertions, 32 deletions
diff --git a/kernel/taskstats.c b/kernel/taskstats.c index ea9506de3b855..4a0a5022b2999 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -132,46 +132,79 @@ static int fill_pid(pid_t pid, struct task_struct *pidtsk, static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, struct taskstats *stats) { - int rc; struct task_struct *tsk, *first; + unsigned long flags; + /* + * Add additional stats from live tasks except zombie thread group + * leaders who are already counted with the dead tasks + */ first = tgidtsk; - read_lock(&tasklist_lock); if (!first) { + read_lock(&tasklist_lock); first = find_task_by_pid(tgid); if (!first) { read_unlock(&tasklist_lock); return -ESRCH; } - } + get_task_struct(first); + read_unlock(&tasklist_lock); + } else + get_task_struct(first); + + /* Start with stats from dead tasks */ + spin_lock_irqsave(&first->signal->stats_lock, flags); + if (first->signal->stats) + memcpy(stats, first->signal->stats, sizeof(*stats)); + spin_unlock_irqrestore(&first->signal->stats_lock, flags); + tsk = first; + read_lock(&tasklist_lock); do { + if (tsk->exit_state == EXIT_ZOMBIE && thread_group_leader(tsk)) + continue; /* - * Each accounting subsystem adds calls its functions to + * Accounting subsystem can call its functions here to * fill in relevant parts of struct taskstsats as follows * - * rc = per-task-foo(stats, tsk); - * if (rc) - * break; + * per-task-foo(stats, tsk); */ - - rc = delayacct_add_tsk(stats, tsk); - if (rc) - break; + delayacct_add_tsk(stats, tsk); } while_each_thread(first, tsk); read_unlock(&tasklist_lock); stats->version = TASKSTATS_VERSION; - /* - * Accounting subsytems can also add calls here if they don't - * wish to aggregate statistics for per-tgid stats + * Accounting subsytems can also add calls here to modify + * fields of taskstats. */ - return rc; + return 0; +} + + +static void fill_tgid_exit(struct task_struct *tsk) +{ + unsigned long flags; + + spin_lock_irqsave(&tsk->signal->stats_lock, flags); + if (!tsk->signal->stats) + goto ret; + + /* + * Each accounting subsystem calls its functions here to + * accumalate its per-task stats for tsk, into the per-tgid structure + * + * per-task-foo(tsk->signal->stats, tsk); + */ + delayacct_add_tsk(tsk->signal->stats, tsk); +ret: + spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); + return; } + static int taskstats_send_stats(struct sk_buff *skb, struct genl_info *info) { int rc = 0; @@ -230,7 +263,7 @@ err: /* Send pid data out on exit */ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, - struct taskstats *tgidstats) + int group_dead) { int rc; struct sk_buff *rep_skb; @@ -238,13 +271,16 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, size_t size; int is_thread_group; struct nlattr *na; + unsigned long flags; if (!family_registered || !tidstats) return; - is_thread_group = !thread_group_empty(tsk); - rc = 0; + spin_lock_irqsave(&tsk->signal->stats_lock, flags); + is_thread_group = tsk->signal->stats ? 1 : 0; + spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); + rc = 0; /* * Size includes space for nested attributes */ @@ -268,30 +304,28 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, *tidstats); nla_nest_end(rep_skb, na); - if (!is_thread_group || !tgidstats) { - send_reply(rep_skb, 0, TASKSTATS_MSG_MULTICAST); - goto ret; - } + if (!is_thread_group) + goto send; - rc = fill_tgid(tsk->pid, tsk, tgidstats); /* - * If fill_tgid() failed then one probable reason could be that the - * thread group leader has exited. fill_tgid() will fail, send out - * the pid statistics collected earlier. + * tsk has/had a thread group so fill the tsk->signal->stats structure + * Doesn't matter if tsk is the leader or the last group member leaving */ - if (rc < 0) { - send_reply(rep_skb, 0, TASKSTATS_MSG_MULTICAST); - goto ret; - } + + fill_tgid_exit(tsk); + if (!group_dead) + goto send; na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid); + /* No locking needed for tsk->signal->stats since group is dead */ NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, - *tgidstats); + *tsk->signal->stats); nla_nest_end(rep_skb, na); +send: send_reply(rep_skb, 0, TASKSTATS_MSG_MULTICAST); - goto ret; + return; nla_put_failure: genlmsg_cancel(rep_skb, reply); |