[PATCH] BKL reduction in do_exit

Push BKL down to the (few) routines that actually need it,
remove it from the do_exit() path.

drivers/char/tty_io.c

@@ -569,6 +569,8 @@ void disassociate_ctty(int on_exit)
 	struct task_struct *p;
 	int tty_pgrp = -1;
 
+	lock_kernel();
+
 	if (tty) {
 		tty_pgrp = tty->pgrp;
 		if (on_exit && tty->driver.type != TTY_DRIVER_TYPE_PTY)
@@ -578,6 +580,7 @@ void disassociate_ctty(int on_exit)
 			kill_pg(current->tty_old_pgrp, SIGHUP, on_exit);
 			kill_pg(current->tty_old_pgrp, SIGCONT, on_exit);
 		}
+		unlock_kernel();	
 		return;
 	}
 	if (tty_pgrp > 0) {
@@ -595,6 +598,7 @@ void disassociate_ctty(int on_exit)
 	  	if (p->session == current->session)
 			p->tty = NULL;
 	read_unlock(&tasklist_lock);
+	unlock_kernel();
 }
 
 void stop_tty(struct tty_struct *tty)

ipc/sem.c

@@ -995,6 +995,8 @@ void sem_exit (void)
 	struct sem_array *sma;
 	int nsems, i;
 
+	lock_kernel();
+
 	/* If the current process was sleeping for a semaphore,
 	 * remove it from the queue.
 	 */
@@ -1051,6 +1053,8 @@ void sem_exit (void)
 		sem_unlock(semid);
 	}
 	current->semundo = NULL;
+
+	unlock_kernel();
 }
 
 #ifdef CONFIG_PROC_FS

kernel/exit.c

@@ -494,7 +494,6 @@ NORET_TYPE void do_exit(long code)
 	acct_process(code);
 	__exit_mm(tsk);
 
-	lock_kernel();
 	sem_exit();
 	__exit_files(tsk);
 	__exit_fs(tsk);