Remove dead code in sched.c

36ebee8f · Silas Boyd-Wickizer · eca599b3 · 36ebee8f
--- a/sched.c
+++ b/sched.c
@@ -130,107 +130,3 @@ initsched(void)
    STAILQ_INIT(&runq[i].q);
  }
 }
-#if 0
-// XXX(sbw) This code is broken.  It essentially implements "LIFO"
-// scheduling, which leads to starvation and deadlock (in userspace).
-struct ns *nsrunq __mpalign__;
-// Mark a process RUNNABLE and add it to the runq
-// of its cpu. Caller must hold p->lock so that
-// some other core doesn't start running the
-// process before the caller has finished setting
-// the process up, and to cope with racing callers
-// e.g. two wakeups on same process. and to
-// allow atomic addrun(); sched();
-void
-addrun(struct proc *p)
-{
-#if SPINLOCK_DEBUG
-  if(!holding(&p->lock))
-    panic("addrun no p->lock");
-#endif
-  if (p->on_runq >= 0)
-    panic("addrun on runq already");
-  ns_insert(nsrunq, KI(p->cpuid), p);
-  p->on_runq = p->cpuid;
-}
-void
-delrun(struct proc *p)
-{
-#if SPINLOCK_DEBUG
-  if(!holding(&p->lock))
-    panic("delrun no p->lock");
-#endif
-  if (p->on_runq < 0)
-    panic("delrun not on runq");
-  if (ns_remove(nsrunq, KI(p->on_runq), p) == 0)
-    panic("delrun: ns_remove");
-  p->on_runq = -1;
-}
-static void *
-steal_cb(void *vk, void *v, void *arg)
-{
-  struct proc *p = v;
-  acquire(&p->lock);
-  if (p->state != RUNNABLE || p->cpuid == mycpu()->id || p->cpu_pin) {
-    release(&p->lock);
-    return 0;
-  }
-  if (p->curcycles == 0 || p->curcycles > VICTIMAGE) {
-    if (sched_debug)
-      cprintf("cpu%d: steal %d (cycles=%d) from %d\n",
-	      mycpu()->id, p->pid, (int)p->curcycles, p->cpuid);
-    delrun(p);
-    p->curcycles = 0;
-    p->cpuid = mycpu()->id;
-    addrun(p);
-    release(&p->lock);
-    return p;
-  }
-  release(&p->lock);
-  return 0;
-}
-int
-steal(void)
-{
-  void *stole = ns_enumerate(nsrunq, steal_cb, 0);
-  return stole ? 1 : 0;
-}
-static void *
-choose_runnable(void *pp, void *arg)
-{
-  struct proc *head = pp;
-  if (head->state == RUNNABLE)
-    return head;
-  return 0;
-}
-struct proc *
-schednext(void)
-{
-  // XXX(sbw) Yikes!  If two processes are runnable on the same
-  // CPU this will always return to process addrun inserted last 
-  // into the ns.
-  return ns_enumerate_key(nsrunq, KI(mycpu()->id), choose_runnable, 0);
-}
-void
-initsched(void)
-{
-  nsrunq = nsalloc(1);
-  if (nsrunq == 0)
-    panic("pinit runq");
-}
-#endif