[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>
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 2039585..f45c5e7 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -455,10 +455,9 @@
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 @@
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 @@
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;