diff -Nru linux-2.4.12.vanilla/include/linux/sched.h linux-2.4.12.scx/include/linux/sched.h
--- linux-2.4.12.vanilla/include/linux/sched.h	Thu Oct 11 10:40:49 2001
+++ linux-2.4.12.scx/include/linux/sched.h	Fri Oct 19 11:52:43 2001
@@ -393,12 +393,14 @@
 	int (*notifier)(void *priv);
 	void *notifier_data;
 	sigset_t *notifier_mask;
-	
+
 /* Thread group tracking */
    	u32 parent_exec_id;
    	u32 self_exec_id;
 /* Protection of (de-)allocation: mm, files, fs, tty */
 	spinlock_t alloc_lock;
+/* a better place for these brothers must be found */
+	unsigned long cpu_jtime, sched_jtime;
 };
 
 /*
@@ -485,7 +487,8 @@
     sig:		&init_signals,					\
     pending:		{ NULL, &tsk.pending.head, {{0}}},		\
     blocked:		{{0}},						\
-    alloc_lock:		SPIN_LOCK_UNLOCKED				\
+    alloc_lock:		SPIN_LOCK_UNLOCKED,				\
+	cpu_jtime:		0 \
 }
 
 
@@ -808,7 +811,7 @@
 	current->state = TASK_RUNNING;					\
 	remove_wait_queue(&wq, &__wait);				\
 } while (0)
-	
+
 #define wait_event_interruptible(wq, condition)				\
 ({									\
 	int __ret = 0;							\
diff -Nru linux-2.4.12.vanilla/kernel/fork.c linux-2.4.12.scx/kernel/fork.c
--- linux-2.4.12.vanilla/kernel/fork.c	Mon Oct  1 12:56:42 2001
+++ linux-2.4.12.scx/kernel/fork.c	Thu Oct 18 17:12:49 2001
@@ -687,6 +687,9 @@
 	if (!current->counter)
 		current->need_resched = 1;
 
+	p->cpu_jtime = 0;
+	p->sched_jtime = jiffies;
+
 	/*
 	 * Ok, add it to the run-queues and make it
 	 * visible to the rest of the system.
diff -Nru linux-2.4.12.vanilla/kernel/sched.c linux-2.4.12.scx/kernel/sched.c
--- linux-2.4.12.vanilla/kernel/sched.c	Tue Oct  9 19:00:29 2001
+++ linux-2.4.12.scx/kernel/sched.c	Fri Oct 19 14:32:40 2001
@@ -167,13 +167,25 @@
 		weight = p->counter;
 		if (!weight)
 			goto out;
-			
+
 #ifdef CONFIG_SMP
 		/* Give a largish advantage to the same processor...   */
 		/* (this is equivalent to penalizing other processors) */
-		if (p->processor == this_cpu)
+		if (p->processor == this_cpu) {
 			weight += PROC_CHANGE_PENALTY;
-#endif
+			/* add advantage related to the history of this task on this cpu
+			 * this try to account the cache footprint of p in this_cpu
+			 */
+			if (p->cpu_jtime > jiffies)
+				weight += p->cpu_jtime - jiffies;
+		}
+#else	/* #ifdef CONFIG_SMP */
+		/* add advantage related to the history of this task on this cpu
+			 * this try to account the cache footprint of p in this_cpu
+			 */
+		if (p->cpu_jtime > jiffies)
+			weight += p->cpu_jtime - jiffies;
+#endif	/* #ifdef CONFIG_SMP */
 
 		/* .. and a slight advantage to the current MM */
 		if (p->mm == this_mm || !p->mm)
@@ -382,7 +394,7 @@
  * delivered to the current task. In this case the remaining time
  * in jiffies will be returned, or 0 if the timer expired in time
  *
- * The current task state is guaranteed to be TASK_RUNNING when this 
+ * The current task state is guaranteed to be TASK_RUNNING when this
  * routine returns.
  *
  * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
@@ -574,7 +586,15 @@
 		case TASK_RUNNING:;
 	}
 	prev->need_resched = 0;
-
+	/* we certainly do not want to do this onto the idle task */
+	if (prev != idle_task(this_cpu)) {
+		/* this save the cpu time that has not been consumed by the previous preemption */
+		prev->cpu_jtime -= prev->cpu_jtime > prev->sched_jtime ? prev->sched_jtime: 0;
+		/* recalculate the cpu time. note that (i - j) + i != 2 * i - j because you might
+		 * overflow the unsigned long type
+		 */
+		prev->cpu_jtime += (jiffies - prev->sched_jtime) + jiffies;
+	}
 	/*
 	 * this is the scheduler proper:
 	 */
@@ -611,6 +631,7 @@
  	next->has_cpu = 1;
 	next->processor = this_cpu;
 #endif
+	next->sched_jtime = jiffies;
 	spin_unlock_irq(&runqueue_lock);
 
 	if (prev == next) {
@@ -1321,6 +1342,8 @@
 			smp_processor_id(), current->pid);
 		del_from_runqueue(current);
 	}
+	current->cpu_jtime = 0;
+	current->sched_jtime = jiffies;
 	sched_data->curr = current;
 	sched_data->last_schedule = get_cycles();
 	clear_bit(current->processor, &wait_init_idle);