Index: linux-2.6.12-rc5-uiddep/kernel/sched.c
===================================================================
--- linux-2.6.12-rc5-uiddep.orig/kernel/sched.c	2005-05-29 19:54:30.000000000 +1000
+++ linux-2.6.12-rc5-uiddep/kernel/sched.c	2005-06-01 21:46:54.000000000 +1000
@@ -2530,6 +2530,21 @@ static inline int dependent_sleeper(int 
 		task_t *smt_curr = smt_rq->curr;
 
 		/*
+		 * Don't let tasks from different users run on siblings that
+		 * share caches to avoid the security risk of cache misses.
+		 * If an equal priority task is already running let that one
+		 * continue, otherwise let only the better priority task run.
+		 */
+		if (p->uid != smt_curr->uid && p->mm && smt_curr->mm) {
+			if (smt_curr->prio <= p->prio) {
+				ret = 1;
+				continue;
+			}
+			resched_task(smt_curr);
+			continue;
+		}
+
+		/*
 		 * If a user task with lower static priority than the
 		 * running task on the SMT sibling is trying to schedule,
 		 * delay it till there is proportionately less timeslice