signals: kill the awful task_rq_unlock_wait() hack

Now that task->signal can't go away we can revert the horrible hack added
by ad474caca3e2a0550b7ce0706527ad5ab389a4d4 ("fix for
account_group_exec_runtime(), make sure ->signal can't be freed under
rq->lock").

And we can do more cleanups sched_stats.h/posix-cpu-timers.c later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 5 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 356d91fa095f..bbc790646502 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -145,11 +145,6 @@ static void __exit_signal(struct task_struct *tsk)
         if (sig) {
                 flush_sigqueue(&sig->shared_pending);
                 taskstats_tgid_free(sig);
-                /*
-                 * Make sure ->signal can't go away under rq->lock,
-                 * see account_group_exec_runtime().
-                 */
-                task_rq_unlock_wait(tsk);
                 tty_kref_put(tty);
         }
 }