[PATCH] do_group_exit: don't take tasklist_lock

do_group_exit() takes tasklist_lock for zap_other_threads(), this is unneeded
now.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/exit.c b/kernel/exit.c
index 44d6c6e3896dd7b01b16225c97f8adb00b6438a8..aea23e713cf46ec10b6f71bf038fd79bccd82e37 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -985,7 +985,6 @@ do_group_exit(int exit_code)
        else if (!thread_group_empty(current)) {
                struct signal_struct *const sig = current->signal;
                struct sighand_struct *const sighand = current->sighand;
-               read_lock(&tasklist_lock);
                spin_lock_irq(&sighand->siglock);
                if (sig->flags & SIGNAL_GROUP_EXIT)
                        /* Another thread got here before we took the lock.  */
@@ -995,7 +994,6 @@ do_group_exit(int exit_code)
                        zap_other_threads(current);
                }
                spin_unlock_irq(&sighand->siglock);
-               read_unlock(&tasklist_lock);
        }
 
        do_exit(exit_code);