redefine thread_group_leader() as exit_signal >= 0

Change de_thread() to set old_leader->exit_signal = -1. This is
good for the consistency, it is no longer the leader and all
sub-threads have exit_signal = -1 set by copy_process(CLONE_THREAD).

And this allows us to micro-optimize thread_group_leader(), it can
simply check exit_signal >= 0. This also makes sense because we
should move ->group_leader from task_struct to signal_struct.

Signed-off-by: Oleg Nesterov <[email protected]>
Reviewed-by: Tejun Heo <[email protected]>
This commit is contained in:
Oleg Nesterov 2011-06-22 23:10:26 +02:00
commit 087806b128
2 changed files with 5 additions and 2 deletions

View file

@ -963,6 +963,7 @@ static int de_thread(struct task_struct *tsk)
leader->group_leader = tsk;
tsk->exit_signal = SIGCHLD;
leader->exit_signal = -1;
BUG_ON(leader->exit_state != EXIT_ZOMBIE);
leader->exit_state = EXIT_DEAD;