diff -rNu linux-O6/kernel/futex.c linux-O7/kernel/futex.c
--- linux-O6/kernel/futex.c	2003-02-11 10:38:52.000000000 +0100
+++ linux-O7/kernel/futex.c	2003-02-11 10:39:11.000000000 +0100
@@ -58,6 +58,47 @@
 static struct list_head futex_queues[1<<FUTEX_HASHBITS];
 static spinlock_t futex_lock = SPIN_LOCK_UNLOCKED;
 
+static int list_len(struct list_head *head)
+{
+	int count = 0;
+	struct list_head *tmp;
+
+	if (!head)
+		return -1;
+
+	list_for_each(tmp, head)
+		count++;
+
+	return count;
+}
+
+#define __FPRINT(format,uaddr, uval, len, args...) \
+	printk("%ld.%02ld #%d/%5d %p [%5d]#%2d| " format "\n", jiffies/HZ, jiffies%HZ, smp_processor_id(), current->pid, (int *)uaddr, uval, len, args);
+#define FPRINT(format,uaddr, uval, len, args...) \
+	if (unlikely(futex_debug)) \
+		__FPRINT(format,uaddr,uval,len,args);
+		
+#define __FDEBUG(format,args...) \
+do { \
+	unsigned int uval; \
+	if (likely(!futex_debug)) \
+		break; \
+	if (get_user(uval, (int *)uaddr)) \
+		uval = -EFAULT; \
+	__FPRINT(format,uaddr,uval,list_len(head),args); \
+} while (0)
+
+#define FDEBUG(format,args...) \
+do { \
+	if (likely(!futex_debug)) \
+		break; \
+	spin_lock(&futex_lock); \
+	__FDEBUG(format,args); \
+	spin_unlock(&futex_lock); \
+} while (0)
+
+int futex_debug;
+
 /*
  * These are all locks that are necessery to look up a physical
  * mapping safely, and modify/search the futex hash, atomically:
@@ -145,6 +186,22 @@
 	put_page(page);
 }
 
+static int futex_pid (struct futex_q *q)
+{
+	task_t *p;
+	struct list_head *tmp;
+
+	if (!q)
+		return -1;
+	tmp = q->waiters.task_list.next;
+	if (!tmp || list_empty(tmp))
+		return -1;
+	p = list_entry(q->waiters.task_list.next, wait_queue_t,task_list)->task;
+	if (!p)
+		return -1;
+	return p->pid;
+}
+
 /*
  * Wake up all waiters hashed on the physical page that is mapped
  * to this virtual address:
@@ -170,6 +227,7 @@
 
 		if (this->page == page && this->offset == offset) {
 			list_del_init(i);
+			__FDEBUG("     WAKING %d.", futex_pid(this));
 			__detach_vcache(&this->vcache);
 			tell_waiter(this);
 			ret++;
@@ -177,9 +235,9 @@
 				break;
 		}
 	}
-
 	unlock_futex_mm();
 	unpin_page(page);
+	FDEBUG("  WOKE: %d.", ret);
 
 	return ret;
 }
@@ -220,31 +278,38 @@
 	 * to make sure a COW properly rehashes the futex-queue.
 	 */
 	__attach_vcache(&q->vcache, uaddr, current->mm, futex_vcache_callback);
+	__FDEBUG("%s", "  QUEUED");
 }
 
 /* Return 1 if we were still queued (ie. 0 means we were woken) */
-static inline int unqueue_me(struct futex_q *q)
+static inline int unqueue_me(struct futex_q *q, void *uaddr)
 {
+	struct list_head *head;
 	int ret = 0;
 
 	spin_lock(&vcache_lock);
 	spin_lock(&futex_lock);
+	head = q->list.next;
 	if (!list_empty(&q->list)) {
 		list_del(&q->list);
 		__detach_vcache(&q->vcache);
 		ret = 1;
 	}
+	__FDEBUG("%s", "  UNQUEUED");
 	spin_unlock(&futex_lock);
 	spin_unlock(&vcache_lock);
 	return ret;
 }
 
+#define time_val(time) (time == 2147483647 ? -1 : time)
+
 static int futex_wait(unsigned long uaddr,
 		      int offset,
 		      int val,
 		      unsigned long time)
 {
 	DECLARE_WAITQUEUE(wait, current);
+	struct list_head *head;
 	int ret = 0, curval;
 	struct page *page;
 	struct futex_q q;
@@ -267,7 +332,10 @@
 		ret = -EFAULT;
 		goto out;
 	}
+
+	head = &q.list;
 	if (curval != val) {
+		FDEBUG("    CHANGE: %d != %d", curval, val);
 		ret = -EWOULDBLOCK;
 		goto out;
 	}
@@ -280,8 +348,12 @@
 	 */
 	add_wait_queue(&q.waiters, &wait);
 	set_current_state(TASK_INTERRUPTIBLE);
-	if (!list_empty(&q.list))
+	if (!list_empty(&q.list)) {
+		FDEBUG("    ==> AWAY, t:%ld, %d == %d", time_val(time), curval, val);
 		time = schedule_timeout(time);
+		FDEBUG("    <== BACK, t:%ld, sig:%d", time_val(time), signal_pending(current));
+	}
+
 	set_current_state(TASK_RUNNING);
 	/*
 	 * NOTE: we dont remove ourselves from the waitqueue because
@@ -295,7 +367,7 @@
 		ret = -EINTR;
 out:
 	/* Were we woken up anyway? */
-	if (!unqueue_me(&q))
+	if (!unqueue_me(&q, (void *)uaddr))
 		ret = 0;
 	unpin_page(page);
 
@@ -330,6 +402,8 @@
 	if (pos_in_page % sizeof(int))
 		return -EINVAL;
 
+	FPRINT("ENTER SYS op:%d, v:%d", uaddr, val, -1, op, val);
+
 	switch (op) {
 	case FUTEX_WAIT:
 		ret = futex_wait_utime(uaddr, pos_in_page, val, utime);
@@ -351,6 +425,7 @@
 	default:
 		ret = -EINVAL;
 	}
+	FPRINT("EXIT SYS op:%d, v:%d, ret:%d", uaddr, val, -1, op, val, ret);
 	return ret;
 }
 
diff -rNu linux-O6/kernel/sysctl.c linux-O7/kernel/sysctl.c
--- linux-O6/kernel/sysctl.c	2003-02-11 10:38:52.000000000 +0100
+++ linux-O7/kernel/sysctl.c	2003-02-11 10:39:11.000000000 +0100
@@ -42,6 +42,7 @@
 /* External variables not in a header file. */
 extern int panic_timeout;
 extern int print_fatal_signals;
+extern int futex_debug;
 extern int C_A_D;
 extern int bdf_prm[], bdflush_min[], bdflush_max[];
 extern int sysctl_overcommit_memory;
@@ -177,6 +178,8 @@
 	 0644, NULL, &proc_dointvec},
 	{KERN_PANIC, "print_fatal_signals", &print_fatal_signals, sizeof(int),
 	 0644, NULL, &proc_dointvec},
+	 {KERN_PANIC, "futex_debug", &futex_debug, sizeof(int),
+	  0644, NULL, &proc_dointvec},
 	{KERN_CORE_USES_PID, "core_uses_pid", &core_uses_pid, sizeof(int),
 	 0644, NULL, &proc_dointvec},
 	{KERN_CORE_PATTERN, "core_pattern", core_pattern, 64,