signal: do_signal_stop: Remove the unneeded task_clear_group_stop_pending()

PF_EXITING or TASK_STOPPED has already called task_participate_group_stop()
and cleared its ->group_stop. No need to do task_clear_group_stop_pending()
when we start the new group stop.

Add a small comment to explain the !task_is_stopped() check. Note that this
check is not exactly right and it can lead to unnecessary stop later if the
thread is TASK_PTRACED. What we need is task_participated_in_group_stop(),
this will be solved later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Oleg Nesterov 2011-04-01 20:12:16 +02:00 коммит произвёл Tejun Heo
Родитель 1deac632fc
Коммит 780006eac2
1 изменённых файлов: 2 добавлений и 3 удалений

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@ -1866,7 +1866,8 @@ static int do_signal_stop(int signr)
* still in effect and then receive a stop signal and
* initiate another group stop. This deviates from the
* usual behavior as two consecutive stop signals can't
* cause two group stops when !ptraced.
* cause two group stops when !ptraced. That is why we
* also check !task_is_stopped(t) below.
*
* The condition can be distinguished by testing whether
* SIGNAL_STOP_STOPPED is already set. Don't generate
@ -1896,8 +1897,6 @@ static int do_signal_stop(int signr)
t->group_stop |= signr | gstop;
sig->group_stop_count++;
signal_wake_up(t, 0);
} else {
task_clear_group_stop_pending(t);
}
}
}