wq nits

b92d178d · Silas Boyd-Wickizer · cfd454fc · b92d178d
--- a/kernel/wq.cc
+++ b/kernel/wq.cc
@@ -109,10 +109,18 @@ wq_push2(void (*fn)(struct work*, void*, void*), void *a0, void *a1)
  return 0;
 }

-static struct work *
+static void
+__wq_run(struct work *w)
+{
+  void (*fn)(struct work*, void*, void*, void*, void*, void*) = 
+    (void(*)(work*,void*,void*,void*,void*,void*))w->rip;
+  fn(w, w->arg0, w->arg1, w->arg2, w->arg3, w->arg4);
+  freework(w);
+}
+
+static inline struct work *
 __wq_pop(int c)
 {
-  // Called with cli
  struct wqueue *wq = &queue[c];
  struct work *w;
  int i;
@@ -136,10 +144,9 @@ __wq_pop(int c)
  return w;
 }

-static struct work *
+static inline struct work *
 __wq_steal(int c)
 {
-  // Called with cli
  struct wqueue *wq = &queue[c];
  struct work *w;
  int i;
@@ -160,42 +167,34 @@ __wq_steal(int c)
  return w;
 }

-static void
-__wq_run(struct work *w)
-{
-  void (*fn)(struct work*, void*, void*, void*, void*, void*) = 
-    (void(*)(work*,void*,void*,void*,void*,void*))w->rip;
-  fn(w, w->arg0, w->arg1, w->arg2, w->arg3, w->arg4);
-  freework(w);
-}
-
 int
 wq_trywork(void)
 {
  struct work *w;
-  int i;
+  int i, k;
+
+  // A "random" victim CPU
+  k = rdtsc();

-  //pushcli();
  w = __wq_pop(mycpu()->id);
  if (w != nullptr) {
    __wq_run(w);
-    //popcli();
    return 1;
  }
-  // XXX(sbw) should be random
+
  for (i = 0; i < NCPU; i++) {
-    if (i == mycpu()->id)
+    int j = (i+k) % NCPU;
+
+    if (j == mycpu()->id)
        continue;
    
-    w = __wq_steal(i);
+    w = __wq_steal(j);
    if (w != nullptr) {
      __wq_run(w);
-      //popcli();
      return 1;
    }
  }

-  //popcli();
  return 0;
 }