[PATCH] taskstats: fix sub-threads accounting

If there are no listeners, taskstats_exit_send() just returns because
taskstats_exit_alloc() didn't allocate *tidstats.  This is wrong, each
sub-thread should do fill_tgid_exit() on exit, otherwise its ->delays is
not recorded in ->signal->stats and lost.

Q: We don't send TASKSTATS_TYPE_AGGR_TGID when single-threaded process
exits.  Is it good?  How can the listener figure out that it was actually a
process exit, not sub-thread?

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Balbir Singh <balbir@in.ibm.com>
Acked-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Oleg Nesterov 2006-10-30 22:07:15 -08:00 committed by Linus Torvalds
parent 525fdb6cc9
commit 4a279ff1ea

View file

@ -455,10 +455,9 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats,
int is_thread_group;
struct nlattr *na;
if (!family_registered || !tidstats)
if (!family_registered)
return;
rc = 0;
/*
* Size includes space for nested attributes
*/
@ -466,8 +465,15 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats,
nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
is_thread_group = (tsk->signal->stats != NULL);
if (is_thread_group)
size = 2 * size; /* PID + STATS + TGID + STATS */
if (is_thread_group) {
/* PID + STATS + TGID + STATS */
size = 2 * size;
/* fill the tsk->signal->stats structure */
fill_tgid_exit(tsk);
}
if (!tidstats)
return;
rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size);
if (rc < 0)
@ -487,11 +493,8 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats,
goto send;
/*
* 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
*/
fill_tgid_exit(tsk);
if (!group_dead)
goto send;