diff -urN linux-2.4.19-pre9-O1/arch/i386/kernel/entry.S linux/arch/i386/kernel/entry.S
--- linux-2.4.19-pre9-O1/arch/i386/kernel/entry.S	Mon Jun  3 17:28:52 2002
+++ linux/arch/i386/kernel/entry.S	Mon Jun  3 17:21:12 2002
@@ -641,6 +641,7 @@
 	.long SYMBOL_NAME(sys_ni_syscall)	/* 240 reserved for futex */
 	.long SYMBOL_NAME(sys_ni_syscall)	/* reserved for sched_setaffinity */
 	.long SYMBOL_NAME(sys_ni_syscall)	/* reserved for sched_getaffinity */
+	.long SYMBOL_NAME(sys_sched_hint)
 
 	.rept NR_syscalls-(.-sys_call_table)/4
 		.long SYMBOL_NAME(sys_ni_syscall)
diff -urN linux-2.4.19-pre9-O1/include/asm-i386/unistd.h linux/include/asm-i386/unistd.h
--- linux-2.4.19-pre9-O1/include/asm-i386/unistd.h	Mon Jun  3 17:27:16 2002
+++ linux/include/asm-i386/unistd.h	Mon Jun  3 17:19:31 2002
@@ -247,6 +247,7 @@
 #define __NR_futex		240
 #define __NR_sched_setaffinity	241
 #define __NR_sched_getaffinity	242
+#define __NR_sched_hint		243
 
 /* user-visible error numbers are in the range -1 - -124: see <asm-i386/errno.h> */
 
diff -urN linux-2.4.19-pre9-O1/include/linux/sched.h linux/include/linux/sched.h
--- linux-2.4.19-pre9-O1/include/linux/sched.h	Mon Jun  3 17:28:53 2002
+++ linux/include/linux/sched.h	Mon Jun  3 17:19:31 2002
@@ -115,6 +115,13 @@
 #endif
 
 /*
+ * Scheduling Hints
+ */
+#define HINT_TIME		1	/* increase remaining timeslice */
+#define HINT_INTERACTIVE	2	/* interactive task: prio bonus */
+#define HINT_BATCH		4	/* batch task: prio penalty */
+
+/*
  * Scheduling policies
  */
 #define SCHED_OTHER		0
diff -urN linux-2.4.19-pre9-O1/kernel/sched.c linux/kernel/sched.c
--- linux-2.4.19-pre9-O1/kernel/sched.c	Mon Jun  3 17:28:53 2002
+++ linux/kernel/sched.c	Mon Jun  3 17:19:38 2002
@@ -1179,6 +1179,64 @@
 	return retval;
 }
 
+/*
+ * sys_sched_hint - give the scheduler a hint to (hopefully) provide
+ * better scheduling behavior.  For example, if a task is about
+ * to acquire a highly contended resource, it would be wise to
+ * increase its remaining timeslice to ensure it could drop the
+ * resource before being preempted.
+ *
+ * `hint' is the hint to the scheduler, defined in include/linux/sched.h
+ */
+asmlinkage int sys_sched_hint(unsigned long hint)
+{
+	int ret = -EINVAL;
+	unsigned long flags;
+	runqueue_t *rq;
+
+	/*
+	 * Requiring CAP_SYS_NICE is an issue: we really want any task
+	 * to be able to give the scheduler a `hint' but we have no
+	 * way of ensuring fairness.  The compromise is to require
+	 * some sort of permission... you may want to get rid of this.
+	 */
+	if (!capable(CAP_SYS_NICE))
+		return -EPERM;
+
+	rq = task_rq_lock(current, &flags);
+
+	if (hint & HINT_TIME) {
+		current->time_slice = MAX_TIMESLICE;
+		/*
+		 * we may have run out of timeslice and have been
+		 * put on the expired runqueue: if so, fix that.
+		 */
+		if (unlikely(current->array != rq->active)) {
+			dequeue_task(current, current->array);
+			enqueue_task(current, rq->active);
+		}
+		ret = 0;
+	}
+
+	if (hint & HINT_INTERACTIVE) {
+		dequeue_task(current, current->array);
+		current->sleep_avg = MAX_SLEEP_AVG;
+		current->prio = effective_prio(current);
+		enqueue_task(current, rq->active);
+		ret = 0;
+	} else if (hint & HINT_BATCH) {
+		dequeue_task(current, current->array);
+		current->sleep_avg = 0;
+		current->prio = effective_prio(current);
+		enqueue_task(current, rq->active);
+		ret = 0;
+	}
+
+	task_rq_unlock(rq, &flags);
+
+	return ret;
+}
+
 asmlinkage long sys_sched_yield(void)
 {
 	runqueue_t *rq;