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, 8 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 054a6012de99..15b93f617fd7 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -969,14 +969,6 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
         }
 }
 
-void task_rq_unlock_wait(struct task_struct *p)
-{
-        struct rq *rq = task_rq(p);
-
-        smp_mb(); /* spin-unlock-wait is not a full memory barrier */
-        raw_spin_unlock_wait(&rq->lock);
-}
-
 static void __task_rq_unlock(struct rq *rq)
         __releases(rq->lock)
 {