--- a/kernel/sys.c.orig	2008-09-01 12:50:22.000000000 +0200
+++ b/kernel/sys.c	2008-09-01 15:11:45.000000000 +0200
@@ -162,15 +162,22 @@
 			else
 				p = current;
 			if (p)
+{printk("setting prio of pid %d tgid %d to %d\n", p->pid, p->tgid, niceval);
 				error = set_one_prio(p, niceval, error);
+}
 			break;
 		case PRIO_PROCESS:
 			if (who)
 				pid = find_vpid(who);
-			else
+			else {
 				pid = task_pid(current);
+				who = current->pid;
+			}
 			do_each_pid_thread(pid, PIDTYPE_PID, p) {
-				error = set_one_prio(p, niceval, error);
+				if (who == p->pid || who == p->tgid) {
+printk("setting prio of pid %d tgid %d to %d\n", p->pid, p->tgid, niceval);
+					error = set_one_prio(p, niceval, error);
+				}
 			} while_each_pid_thread(pid, PIDTYPE_PID, p);
 			break;
 		case PRIO_PGRP:
@@ -231,18 +238,25 @@
 				niceval = 20 - task_nice(p);
 				if (niceval > retval)
 					retval = niceval;
+printk("PRIO_THREAD: pid %d tgid %d: niceval=%ld retval=%ld\n", p->pid, p->tgid, niceval, retval);
 			}
 			break;
 		case PRIO_PROCESS:
 			if (who)
 				pid = find_vpid(who);
-			else
+			else {
 				pid = task_pid(current);
+				who = current->pid;
+			}
 			do_each_pid_thread(pid, PIDTYPE_PID, p) {
-				niceval = 20 - task_nice(p);
-				if (niceval > retval)
-					retval = niceval;
+				if (who == p->pid || who == p->tgid) {
+					niceval = 20 - task_nice(p);
+					if (niceval > retval)
+						retval = niceval;
+printk("PRIO_PROCESS: pid %d tgid %d: niceval=%ld\n", p->pid, p->tgid, niceval);
+				}
 			} while_each_pid_thread(pid, PIDTYPE_PID, p);
+printk("PRIO_PROCESS: returning retval=%ld\n", retval);
 			break;
 		case PRIO_PGRP:
 			if (who)