More usched

a4551d12 · Silas Boyd-Wickizer · 7af1706b · a4551d12
--- a/user/usched.cc
+++ b/user/usched.cc
@@ -194,16 +194,19 @@ runit(proc* p)
  spin_delay(500);
 }

+#if 1
 static proc*
 stealit(void)
 {
  proc* p;

+  int r = stuff_->rnd();
  ANON_REGION("stealit", &perfgroup);
  for (int i = 0; i < NCPU; i++) {
-    if (i == myid_)
+    int k = (r+i)%NCPU;
+    if (k == myid_)
      continue;
-    p = schedule_[i].steal(true);
+    p = schedule_[k].steal(true);
    if (p) {
      return p;
    }
@@ -211,15 +214,40 @@ stealit(void)
  return nullptr;
 }

+#else
+
+static proc*
+stealit(void)
+{
+  proc* p;
+
+  ANON_REGION("stealit", &perfgroup);
+  for (int i = 0; i < 2; i++) {
+    int k = i+myid_-(myid_%2);
+    if (k == myid_)
+      continue;
+    p = schedule_[k].steal(true);
+    if (p) {
+      return p;
+    }
+  }
+  return nullptr;
+}
+#endif
+
 static void
 schedit(void)
 {
  uint32_t r;
  proc* p;

-  p = schedule_->deq();
-  if (p == nullptr)
-    p = stealit();
+  {
+    ANON_REGION("schedit", &perfgroup);
+    
+    p = schedule_->deq();
+    if (p == nullptr)
+      p = stealit();
+  }

  r = stuff_->rnd() % 100;
  if (p) {