Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4a279ff1 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

[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: default avatarOleg Nesterov <oleg@tv-sign.ru>
Cc: Balbir Singh <balbir@in.ibm.com>
Acked-by: default avatarShailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 525fdb6c

kernel/taskstats.c

+10 −7
Original line number Diff line number Diff line
@@ -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;