kernel/ckrm_sched.c

   1 /* kernel/ckrm_sched.c - Supporting functions for ckrm scheduling
   2  *
   3  * Copyright (C) Haoqiang Zheng,  IBM Corp. 2004
   4  *           (C) Hubertus Franke, IBM Corp. 2004
   5  *
   6  * Latest version, more details at http://ckrm.sf.net
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  */
  14 #include <linux/mm.h>
  15 #include <linux/init.h>
  16 #include <linux/ckrm_sched.h>
  17
  18 /*******************************************************/
  19 /*                CVT Management                       */
  20 /*******************************************************/
  21 #define CVT_WINDOW_SIZE (CLASSQUEUE_SIZE << CLASS_BONUS_RATE)
  22 static CVT_t max_CVT = CVT_WINDOW_SIZE;
  23
  24 /*
  25  *  Also ensure that the classes global cvt is upgraded to the
  26  * minimum CVT in the system, as a class might not have run for a while
  27  */
  28 static void update_global_cvt(struct ckrm_cpu_class *cpu_class, int cpu)
  29 {
  30         struct ckrm_local_runqueue *class_queue =
  31             get_ckrm_local_runqueue(cpu_class, cpu);
  32         CVT_t min_cvt;
  33         CVT_t local_cvt_old = class_queue->local_cvt;
  34
  35         spin_lock(&cvt_lock);
  36         if (class_queue->uncounted_cvt) {
  37                 cpu_class->global_cvt += class_queue->uncounted_cvt;
  38                 class_queue->uncounted_cvt = 0;
  39         }
  40         min_cvt = max_CVT - CVT_WINDOW_SIZE;
  41         if (cpu_class->global_cvt < min_cvt)
  42                 cpu_class->global_cvt = min_cvt;
  43         else  if (cpu_class->global_cvt > max_CVT)
  44                 max_CVT = cpu_class->global_cvt;
  45
  46 /* update local cvt from global cvt*/
  47 #if 0
  48         class_queue->local_cvt = cpu_class->global_cvt;
  49 #endif
  50         spin_unlock(&cvt_lock);
  51
  52         if (class_queue->local_cvt != local_cvt_old)
  53                 update_class_priority(class_queue);
  54 }
  55
  56 /*
  57  * class_list_lock must have been acquired
  58  */
  59 void update_global_cvts(int this_cpu)
  60 {
  61         struct ckrm_cpu_class *clsptr;
  62         struct ckrm_local_runqueue *class_queue;
  63
  64         /*for each class*/
  65         list_for_each_entry(clsptr, &active_cpu_classes, links) {
  66                 update_global_cvt(clsptr, this_cpu);
  67                 class_queue = get_ckrm_local_runqueue(clsptr, this_cpu);
  68                 clsptr->stat.total_ns += class_queue->uncounted_ns;
  69                 class_queue->uncounted_ns = 0;
  70         }
  71 }