From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 3 Jul 2009 08:44:44 -0500
Subject: signals: Do not wakeup self

Signals which are delivered by current to current can do without
waking up current :)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 kernel/signal.c |    3 +++
 1 file changed, 3 insertions(+)

Index: linux-stable/kernel/signal.c
===================================================================
--- linux-stable.orig/kernel/signal.c
+++ linux-stable/kernel/signal.c
@@ -684,6 +684,9 @@ void signal_wake_up(struct task_struct *
 
 	set_tsk_thread_flag(t, TIF_SIGPENDING);
 
+	if (unlikely(t == current))
+		return;
+
 	/*
 	 * For SIGKILL, we want to wake it up in the stopped/traced/killable
 	 * case. We don't check t->state here because there is a race with it