diff -r 062311a1fd19 xen/common/sched_credit.c
--- a/xen/common/sched_credit.c	Fri Jun 05 11:37:04 2009 +0100
+++ b/xen/common/sched_credit.c	Fri Jun 05 11:38:43 2009 +0100
@@ -363,15 +363,29 @@
 static int
 csched_cpu_pick(struct vcpu *vc)
 {
-    cpumask_t cpus;
+    cpumask_t cpus, cpus_avoid_same_domain;
     cpumask_t idlers;
     int cpu;
+    struct vcpu *vp;
 
     /*
      * Pick from online CPUs in VCPU's affinity mask, giving a
      * preference to its current processor if it's in there.
      */
     cpus_and(cpus, cpu_online_map, vc->cpu_affinity);
+
+    /* Avoid putting vcpus from the same domain on the same cpu */
+    cpus_avoid_same_domain=cpus;
+    for_each_vcpu( vc->domain, vp )
+    {
+        if(vp == vc)
+            continue;
+        cpu_clear(vp->processor, cpus_avoid_same_domain);
+    }
+
+    if( !cpus_empty(cpus_avoid_same_domain) )
+        cpus = cpus_avoid_same_domain;
+
     cpu = cpu_isset(vc->processor, cpus)
             ? vc->processor
             : cycle_cpu(vc->processor, cpus);