linux-2.6-630-sched-fix.patch

   1 diff -Nurp linux-2.6.22-620/kernel/sched.c linux-2.6.22-630/kernel/sched.c
   2 --- linux-2.6.22-620/kernel/sched.c     2008-06-23 17:20:25.000000000 -0400
   3 +++ linux-2.6.22-630/kernel/sched.c     2008-06-24 11:28:41.000000000 -0400
   4 @@ -3635,6 +3635,11 @@ struct event_spec {
   5  };
   6  #endif
   7
   8 +/* Bypass the vx_unhold infinite loop */
   9 +unsigned int merry;
  10 +static int debug_630_dumped = 0;
  11 +EXPORT_SYMBOL(merry);
  12 +
  13  asmlinkage void __sched schedule(void)
  14  {
  15         struct task_struct *prev, *next;
  16 @@ -3722,14 +3727,42 @@ need_resched_nonpreemptible:
  17
  18         cpu = smp_processor_id();
  19         vx_set_rq_time(rq, jiffies);
  20 +
  21 +       merry=0;
  22  try_unhold:
  23         vx_try_unhold(rq, cpu);
  24  pick_next:
  25
  26         if (unlikely(!rq->nr_running)) {
  27                 /* can we skip idle time? */
  28 -               if (vx_try_skip(rq, cpu))
  29 +               if (vx_try_skip(rq, cpu) && merry<10) {
  30 +                       merry++;
  31                         goto try_unhold;
  32 +               }
  33 +               else if (merry==10 && !debug_630_dumped) {
  34 +                       debug_630_dumped = 1;
  35 +                       printk(KERN_EMERG "merry==10!\n");
  36 +                       if (list_empty(&rq->hold_queue))
  37 +                               printk(KERN_EMERG "hold queue is empty\n");
  38 +                       else {
  39 +                               struct list_head *l, *n;
  40 +                               printk(KERN_EMERG "rq->norm_time = %lu, rq->idle_time = %lu, rq->idle_skip = %d\n",
  41 +                                       rq->norm_time, rq->idle_time, rq->idle_skip);
  42 +                               list_for_each_safe(l, n, &rq->hold_queue) {
  43 +                                       struct task_struct *p;
  44 +                                       struct _vx_sched_pc *sched_pc;
  45 +                                       struct vx_info *vxi;
  46 +
  47 +                                       p = list_entry(l, struct task_struct, run_list);
  48 +                                       vxi = p->vx_info;
  49 +                                       sched_pc = &vx_per_cpu(vxi, sched_pc, cpu);
  50 +
  51 +                                       printk(KERN_EMERG "%u: sched_pc->norm_time = %lu, sched_pc->idle_time = %lu\n", vxi->vx_id,
  52 +                                               sched_pc->norm_time, sched_pc->idle_time);
  53 +                               }
  54 +                       }
  55 +               }
  56 +
  57
  58                 idle_balance(cpu, rq);
  59                 if (!rq->nr_running) {