kernel/ckrm/ckrm_cpu_class.c

   1 /* kernel/ckrm/ckrm_cpu_class.c - CPU Class resource controller for CKRM
   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/module.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <asm/errno.h>
  18 #include <linux/sched.h>
  19 #include <linux/ckrm.h>
  20 #include <linux/ckrm_rc.h>
  21 #include <linux/ckrm_tc.h>
  22 #include <linux/ckrm_sched.h>
  23 #include <linux/ckrm_classqueue.h>
  24 #include <linux/seq_file.h>
  25
  26 struct ckrm_res_ctlr cpu_rcbs;
  27
  28 /**
  29  * insert_cpu_class - insert a class to active_cpu_class list
  30  *
  31  * insert the class in decreasing order of class weight
  32  */
  33 static inline void insert_cpu_class(struct ckrm_cpu_class *cls)
  34 {
  35         list_add(&cls->links,&active_cpu_classes);
  36 }
  37
  38 /*
  39  *  initialize a class object and its local queues
  40  */
  41 void init_cpu_class(struct ckrm_cpu_class *cls,ckrm_shares_t* shares)
  42 {
  43         int i,j,k;
  44         prio_array_t *array;
  45         ckrm_lrq_t* queue;
  46
  47         cls->shares = *shares;
  48         cls->cnt_lock = SPIN_LOCK_UNLOCKED;
  49         ckrm_cpu_stat_init(&cls->stat);
  50         cls->magic = CKRM_CPU_CLASS_MAGIC;
  51
  52         for (i = 0 ; i < NR_CPUS ; i++) {
  53                 queue = &cls->local_queues[i];
  54                 queue->active  = queue->arrays;
  55                 queue->expired = queue->arrays+1;
  56
  57                 for (j = 0; j < 2; j++) {
  58                         array = queue->arrays + j;
  59                         for (k = 0; k < MAX_PRIO; k++) {
  60                                 INIT_LIST_HEAD(array->queue + k);
  61                                 __clear_bit(k, array->bitmap);
  62                         }
  63                         // delimiter for bitsearch
  64                         __set_bit(MAX_PRIO, array->bitmap);
  65                         array->nr_active = 0;
  66                 }
  67
  68                 queue->expired_timestamp = 0;
  69
  70                 queue->cpu_class = cls;
  71                 queue->classqueue = get_cpu_classqueue(i);
  72                 queue->top_priority = MAX_PRIO;
  73                 cq_node_init(&queue->classqueue_linkobj);
  74                 queue->local_cvt = CVT_INTERACTIVE_BONUS;
  75                 queue->lrq_load = 0;
  76                 queue->local_weight = cpu_class_weight(cls);
  77                 queue->uncounted_ns = 0;
  78                 queue->magic = 0x43FF43D7;
  79         }
  80
  81         // add to class list
  82         write_lock(&class_list_lock);
  83         insert_cpu_class(cls);
  84         write_unlock(&class_list_lock);
  85 }
  86
  87 static inline void set_default_share(ckrm_shares_t *shares)
  88 {
  89         shares->my_guarantee     = 0;
  90         shares->total_guarantee  = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
  91         shares->unused_guarantee = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
  92         shares->my_limit         = CKRM_SHARE_DFLT_MAX_LIMIT;
  93         shares->max_limit        = CKRM_SHARE_DFLT_MAX_LIMIT;
  94         shares->cur_max_limit    = 0;
  95 }
  96
  97 struct ckrm_cpu_class * ckrm_get_cpu_class(struct ckrm_core_class *core)
  98 {
  99         struct ckrm_cpu_class * cls;
 100         cls = ckrm_get_res_class(core, cpu_rcbs.resid, struct ckrm_cpu_class);
 101         if (valid_cpu_class(cls))
 102                 return cls;
 103         else
 104                 return NULL;
 105 }
 106
 107
 108 void* ckrm_alloc_cpu_class(struct ckrm_core_class *core, struct ckrm_core_class *parent)
 109 {
 110         struct ckrm_cpu_class *cls;
 111
 112         if (! parent) /*root class*/
 113                 cls =  get_default_cpu_class();
 114         else
 115                 cls = (struct ckrm_cpu_class *) kmalloc(sizeof(struct ckrm_cpu_class),GFP_ATOMIC);
 116
 117         if (cls) {
 118                 ckrm_shares_t shares;
 119                 if ((! parent) && (core)) {
 120                         /*
 121                          * the default class is already initialized
 122                          * so only update the core structure
 123                          */
 124                         cls->core = core;
 125                 } else {
 126                         set_default_share(&shares);
 127                         init_cpu_class(cls,&shares);
 128                         cls->core = core;
 129                         cls->parent = parent;
 130                 }
 131         } else
 132                 printk(KERN_ERR"alloc_cpu_class failed\n");
 133
 134         return cls;
 135 }
 136
 137 /*
 138  * hzheng: this is not a stable implementation
 139  *         need to check race condition issue here
 140  */
 141 static void ckrm_free_cpu_class(void *my_res)
 142 {
 143         struct ckrm_cpu_class *cls = my_res, *parres, *childres;
 144         ckrm_core_class_t *child = NULL;
 145         int maxlimit;
 146
 147         if (!cls)
 148                 return;
 149
 150         /*the default class can't be freed*/
 151         if (cls == get_default_cpu_class())
 152                 return;
 153
 154         // Assuming there will be no children when this function is called
 155         parres = ckrm_get_cpu_class(cls->parent);
 156
 157         // return child's limit/guarantee to parent node
 158         spin_lock(&parres->cnt_lock);
 159         child_guarantee_changed(&parres->shares, cls->shares.my_guarantee, 0);
 160         // run thru parent's children and get the new max_limit of the parent
 161         ckrm_lock_hier(parres->core);
 162         maxlimit = 0;
 163         while ((child = ckrm_get_next_child(parres->core, child)) != NULL) {
 164                 childres = ckrm_get_cpu_class(child);
 165                 if (maxlimit < childres->shares.my_limit) {
 166                         maxlimit = childres->shares.my_limit;
 167                 }
 168         }
 169         ckrm_unlock_hier(parres->core);
 170         if (parres->shares.cur_max_limit < maxlimit) {
 171                 parres->shares.cur_max_limit = maxlimit;
 172         }
 173
 174         spin_unlock(&parres->cnt_lock);
 175
 176         write_lock(&class_list_lock);
 177         list_del(&cls->links);
 178         write_unlock(&class_list_lock);
 179
 180         kfree(cls);
 181 }
 182
 183 /*
 184  *  the system will adjust to the new share automatically
 185  */
 186 int ckrm_cpu_set_share(void *my_res, struct ckrm_shares *new_share)
 187 {
 188         struct ckrm_cpu_class *parres, *cls = my_res;
 189         struct ckrm_shares *cur = &cls->shares, *par;
 190         int rc = -EINVAL;
 191
 192         if (!cls)
 193                 return rc;
 194
 195         if (cls->parent) {
 196                 parres = ckrm_get_cpu_class(cls->parent);
 197                 spin_lock(&parres->cnt_lock);
 198                 spin_lock(&cls->cnt_lock);
 199                 par = &parres->shares;
 200         } else {
 201                 spin_lock(&cls->cnt_lock);
 202                 par = NULL;
 203                 parres = NULL;
 204         }
 205
 206         /*
 207          * hzheng: CKRM_SHARE_DONTCARE should be handled
 208          */
 209         if (new_share->my_guarantee == CKRM_SHARE_DONTCARE)
 210                 new_share->my_guarantee = 0;
 211
 212         rc = set_shares(new_share, cur, par);
 213         if (cur->my_limit == CKRM_SHARE_DONTCARE)
 214                 cur->my_limit = cur->max_limit;
 215
 216
 217         spin_unlock(&cls->cnt_lock);
 218         if (cls->parent) {
 219                 spin_unlock(&parres->cnt_lock);
 220         }
 221         return rc;
 222 }
 223
 224 static int ckrm_cpu_get_share(void *my_res,
 225                               struct ckrm_shares *shares)
 226 {
 227         struct ckrm_cpu_class *cls = my_res;
 228
 229         if (!cls)
 230                 return -EINVAL;
 231         *shares = cls->shares;
 232         return 0;
 233 }
 234
 235 int ckrm_cpu_get_stats(void *my_res, struct seq_file * sfile)
 236 {
 237         struct ckrm_cpu_class *cls = my_res;
 238         struct ckrm_cpu_class_stat* stat = &cls->stat;
 239         ckrm_lrq_t* lrq;
 240         int i;
 241
 242         if (!cls)
 243                 return -EINVAL;
 244
 245         seq_printf(sfile, "-------- CPU Class Status Start---------\n");
 246         seq_printf(sfile, "Share:\n\tgrt= %d limit= %d total_grt= %d max_limit= %d\n",
 247                    cls->shares.my_guarantee,
 248                    cls->shares.my_limit,
 249                    cls->shares.total_guarantee,
 250                    cls->shares.max_limit);
 251         seq_printf(sfile, "\tunused_grt= %d cur_max_limit= %d\n",
 252                    cls->shares.unused_guarantee,
 253                    cls->shares.cur_max_limit);
 254
 255         seq_printf(sfile, "Effective:\n\tegrt= %d\n",stat->egrt);
 256         seq_printf(sfile, "\tmegrt= %d\n",stat->megrt);
 257         seq_printf(sfile, "\tehl= %d\n",stat->ehl);
 258         seq_printf(sfile, "\tmehl= %d\n",stat->mehl);
 259         seq_printf(sfile, "\teshare= %d\n",stat->eshare);
 260         seq_printf(sfile, "\tmeshare= %d\n",cpu_class_weight(cls));
 261         seq_printf(sfile, "\ttotal_ns= %llu\n",stat->total_ns);
 262         seq_printf(sfile, "\tmax_demand= %lu\n",stat->max_demand);
 263         for_each_online_cpu(i) {
 264                 lrq = get_ckrm_lrq(cls,i);
 265                 seq_printf(sfile, "\tlrq %d demand= %lu weight= %d lrq_load= %lu cvt= %llu\n",i,stat->local_stats[i].cpu_demand,local_class_weight(lrq),lrq->lrq_load,lrq->local_cvt);
 266         }
 267
 268         seq_printf(sfile, "-------- CPU Class Status END ---------\n");
 269
 270         return 0;
 271 }
 272
 273 /*
 274  * task will remain in the same cpu but on a different local runqueue
 275  */
 276 void ckrm_cpu_change_class(void *task, void *old, void *new)
 277 {
 278         struct task_struct *tsk = task;
 279         struct ckrm_cpu_class *newcls = new;
 280
 281         /*sanity checking*/
 282         if (!task || ! old || !new)
 283                 return;
 284
 285         _ckrm_cpu_change_class(tsk,newcls);
 286 }
 287
 288 /*dummy function, not used*/
 289 static int ckrm_cpu_show_config(void *my_res, struct seq_file *sfile)
 290 {
 291         struct ckrm_cpu_class *cls = my_res;
 292
 293         if (!cls)
 294                 return -EINVAL;
 295
 296         seq_printf(sfile, "cls=%s,parameter=somevalue\n","ckrm_cpu class");
 297         return 0;
 298 }
 299
 300 /*dummy function, not used*/
 301 static int ckrm_cpu_set_config(void *my_res, const char *cfgstr)
 302 {
 303         struct ckrm_cpu_class *cls = my_res;
 304
 305         if (!cls)
 306                 return -EINVAL;
 307         printk("ckrm_cpu config='%s'\n",cfgstr);
 308         return 0;
 309 }
 310
 311 struct ckrm_res_ctlr cpu_rcbs = {
 312         .res_name          = "cpu",
 313         .res_hdepth        = 1,
 314         .resid             = -1,
 315         .res_alloc         = ckrm_alloc_cpu_class,
 316         .res_free          = ckrm_free_cpu_class,
 317         .set_share_values  = ckrm_cpu_set_share,
 318         .get_share_values  = ckrm_cpu_get_share,
 319         .get_stats         = ckrm_cpu_get_stats,
 320         .show_config       = ckrm_cpu_show_config,
 321         .set_config        = ckrm_cpu_set_config,
 322         .change_resclass   = ckrm_cpu_change_class,
 323 };
 324
 325 int __init init_ckrm_sched_res(void)
 326 {
 327         struct ckrm_classtype *clstype;
 328         int resid = cpu_rcbs.resid;
 329
 330         clstype = ckrm_find_classtype_by_name("taskclass");
 331         if (clstype == NULL) {
 332                 printk(KERN_INFO" Unknown ckrm classtype<taskclass>");
 333                 return -ENOENT;
 334         }
 335
 336         if (resid == -1) { /*not registered */
 337                 resid = ckrm_register_res_ctlr(clstype,&cpu_rcbs);
 338                 printk("........init_ckrm_sched_res , resid= %d\n",resid);
 339         }
 340         return 0;
 341 }
 342
 343 /*
 344  * initialize the class structure
 345  * add the default class: class 0
 346  */
 347 void init_cpu_classes(void)
 348 {
 349         int i;
 350
 351         //init classqueues for each processor
 352         for (i=0; i < NR_CPUS; i++)
 353                 classqueue_init(get_cpu_classqueue(i));
 354
 355         /*
 356          * hzheng: initialize the default cpu class
 357          *  required for E14/E15 since ckrm_init is called after sched_init
 358          */
 359         ckrm_alloc_cpu_class(NULL,NULL);
 360 }
 361
 362
 363 EXPORT_SYMBOL(ckrm_get_cpu_class);