Le Thu, 13 Sep 2007 16:41:41 +0400,
Oleg Nesterov <[EMAIL PROTECTED]> a écrit :
> (sorry, have no time to read the patch carefully, just a couple of
> minor random "unless I misread this patch" nits)
Thank you Oleg, hopefully I addressed all your comments in v4.
> > + do
> > + if (!tsk->exit_state)
> > + add_tsk(stats, tsk);
> > + while_each_thread(first, tsk);
>
> This reminds me. The "!tsk->exit_state" is not good and racy, it
> can't prevent the double accounting (of course, I don't blame this
> patch).
I documented this in v4, but I was wondering if always setting
tsk->exit_state under the protection of lock_task_sighand() would fix
the race.
> > + if (thread_group_leader(task)) {
> > + stats->ac_exitcode = task->exit_code;
> > + if (task->flags & PF_FORKNOEXEC)
> > stats->ac_flag |= AFORK;
>
> Actually, I can't understand this "thread_group_leader()" check, but
Seems like this code was copied from kernel/acct.c:acct_collect():
if (thread_group_leader(current)) {
pacct->ac_exitcode = exitcode;
if (current->flags & PF_FORKNOEXEC)
pacct->ac_flag |= AFORK;
}
> I don't know what ->ac_exitcode and AFORK means to the user-space.
>From include/linux/acct.h: executed fork, but did not exec
Except that it talks about fork(2), not do_fork() hence the
thread_group_leader() test to avoid flagging threads.
> But it looks a bit suspicious. Perhaps we need
> ->signal->group_exit_code, not task->exit_code?
I put ->signal->group_exit_code if not null, otherwise
leader->exit_code.
Thank again to you and Andrew for the review.
--
Guillaume
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