palacios/src/extensions/ext_sched_edf.c

   1 /*
   2  * This file is part of the Palacios Virtual Machine Monitor developed
   3  * by the V3VEE Project with funding from the United States National
   4  * Science Foundation and the Department of Energy.
   5  *
   6  * The V3VEE Project is a joint project between Northwestern University
   7  * and the University of New Mexico.  You can find out more at
   8  * http://www.v3vee.org
   9  *
  10  * Copyright (c) 2013, Oscar Mondragon <omondrag@cs.unm.edu>
  11  * Copyright (c) 2013, Patrick G. Bridges <bridges@cs.unm.edu>
  12  * Copyright (c) 2013, The V3VEE Project <http://www.v3vee.org>
  13  * All rights reserved.
  14  *
  15  * Author: Oscar Mondragon <omondrag@cs.unm.edu>
  16  *         Patrick G. Bridges <bridges@cs.unm.edu>
  17  *
  18  * This is free software.  You are permitted to use,
  19  * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
  20  */
  21
  22
  23 #include <palacios/vmm.h>
  24 #include <palacios/vmm_time.h>
  25 #include <palacios/vm_guest.h>
  26 #include <palacios/vmm_hashtable.h>
  27 #include <palacios/vmm_config.h>
  28 #include <palacios/vmm_extensions.h>
  29 #include <palacios/vmm_rbtree.h>
  30
  31
  32 #ifndef V3_CONFIG_DEBUG_EXT_SCHED_EDF
  33 #undef PrintDebug
  34 #define PrintDebug(fmt, args...)
  35 #endif
  36
  37 /* Overview
  38  *
  39  * EDF Scheduling
  40  *
  41  * The EDF scheduler uses a dynamic calculated priority as scheduling criteria to choose
  42  * what thread will be scheduled.That priority is calculated according with the relative
  43  * deadline of the threads that are ready to run in the runqueue. This runqueue is a per-logical
  44  * core data structure used to keep the runnable virtual cores (threads) allocated to that
  45  * logical core.The threads with less time before its deadline will receive better priorities.
  46  * The runqueue is sorted each time that a vCPU becomes runnable or when its period is over.
  47  * At that time the vCPU is enqueue. A new scheduling decision is taken is time that an interruption
  48  * is received. At that time if the earliest deadline core is different that the current core,
  49  * the current core goes to sleep and the earliest deadline core is wake up. Each time a vCPU is scheduled,
  50  * the parameter "used_time" is set to zero and the current deadline is calculated using its period.
  51  * One vCPU uses at least slice seconds of CPU.Some extra time can be allocated to that virtual core after
  52  * all the other virtual cores consumes their slices.
  53  */
  54
  55 // Default configuration values for the EDF Scheduler
  56 // time parameters in microseconds
  57
  58 #define MAX_PERIOD 1000000000
  59 #define MIN_PERIOD 50000
  60 #define MAX_SLICE 1000000000
  61 #define MIN_SLICE 50000
  62 #define CPU_PERCENT 80
  63 #define DEADLINE_INTERVAL 30000000 // Period in which the missed deadline ratio is checked
  64
  65 typedef uint64_t time_us;
  66
  67 /*
  68  * Per-core EDF Scheduling information
  69  */
  70
  71 struct vm_core_edf_sched {
  72     struct guest_info *info;              // Core data struct
  73     struct rb_node node;                  // red-black tree node
  74     time_us period;                       // Amount of time (us) during which the virtual core may received a CPU allocation
  75     time_us slice;                        // Minimum amount of time (us) received for the virtual core during each period
  76     time_us current_deadline;             // Time (us) at which current virtual core period ends
  77     time_us used_time;                    // Amount of time (us) used whiting the current period
  78     time_us last_wakeup_time;             // Time at which the last wakeup started for this virtual core
  79     time_us remaining_time;               // Remaining time (us) to reach the expected time allocated to the virtual core
  80     bool extra_time;                      // Specifies if the virtual core is eligible to receive extra CPU time (For now it is true always)
  81     uint64_t deadline;                    // Total number of deadlines
  82     int deadline_percentage;              // Percentage of total missed deadlines
  83     uint64_t miss_deadline;               // Number of times the core has missed deadlines
  84     uint64_t deadline_interval;           // Total number of deadlines in the latest interval
  85     int deadline_percentage_interval;     // Percentage of missed deadlines in the latest interval
  86     uint64_t miss_deadline_interval;      // Number of times the core has missed deadlines in the last interval
  87     time_us print_deadline_interval;      // Last time missed deadline ratio was printed
  88     time_us total_time;                   // Total scheduled time for this virtual core.
  89     int slice_overuse;                    // Number of times a core consumes extra time
  90     time_us extra_time_given;             // Total extra time given to a virtual core
  91     time_us start_time;                   // Time at which this virtual core start to be scheduled
  92     time_us expected_time;                // Minimum CPU time expected to be allocated to this virtual core
  93
  94 };
  95
  96 /*
  97  * Scheduler configuration
  98  */
  99
 100 struct vm_edf_sched_config {
 101     time_us min_slice;       // Minimum allowed slice
 102     time_us max_slice;       // Maximum allowed slice
 103     time_us min_period;      // Minimum allowed period
 104     time_us max_period;      // Maximum allowed period
 105     int cpu_percent;         // Percentange of CPU utilization for the scheduler in each physical CPU (100 or less)
 106
 107 };
 108
 109 /*
 110  * Run queue structure. Per-logical core data structure  used to keep the runnable virtual cores (threads) allocated to that logical core
 111  * Contains a pointer to the red black tree, the data structure of configuration options, and other info
 112  */
 113
 114 struct vm_edf_rq{
 115
 116     int cpu_u;                                  // CPU utilization (must be less or equal to the cpu_percent in vm_edf_sched_config)
 117     struct rb_root vCPUs_tree;                  // Red-Black Tree
 118     struct vm_edf_sched_config edf_config;      // Scheduling configuration structure
 119     int nr_vCPU;                                // Number of cores in the runqueue
 120     struct vm_core_edf_sched *curr_vCPU;        // Current running CPU
 121     time_us last_sched_time;                    // Last time a virtual core in this runqueue was scheduled
 122     time_us check_deadline_time;                // Last time in which the deadlines were recalculated
 123     time_us smallest_period;                    // Smallest period of the virtual cores in the runqueue, used to control the period of deadlines recalculation
 124     time_us print_time;                         // Last time of debugging print
 125     time_us start_time;                         // Time at which first core started running in this runqueue
 126     int sched_low;                              // Incremented when the time between interruptions is large
 127     bool yielded;                               // CPU yielded to palacios (No core running)
 128 };
 129
 130 /*
 131  * Basic functions for scheduling
 132  */
 133
 134 int v3_init_edf_scheduling();
 135
 136 /*
 137  * Debugging Function
 138  */
 139
 140 static void
 141 print_parameters(time_us host_time, struct vm_edf_rq * runqueue, struct vm_core_edf_sched * core){
 142
 143     time_us elapsed_time = 0;
 144     if(runqueue->start_time != 0)
 145         elapsed_time = host_time - runqueue->start_time;
 146
 147     PrintDebug(core->info->vm_info, core->info,"Test: %llu %llu %d %d %llu %llu %llu %d\n",
 148              host_time,
 149              elapsed_time,
 150              core->info->vcpu_id,
 151              core->info->pcpu_id,
 152              core->total_time,
 153              core->expected_time,
 154              core->miss_deadline,
 155              core->deadline_percentage);
 156
 157    runqueue->print_time = host_time;
 158 }
 159
 160
 161 /*
 162  * init_edf_config: Initialize scheduler configuration
 163  */
 164
 165 static void
 166 init_edf_config(struct vm_edf_sched_config *edf_config){
 167
 168     edf_config->min_slice = MIN_SLICE;
 169     edf_config->max_slice = MAX_SLICE;
 170     edf_config->min_period = MIN_PERIOD;
 171     edf_config->max_period = MAX_PERIOD;
 172     edf_config->cpu_percent = CPU_PERCENT;
 173 }
 174
 175
 176 /*
 177  * priv_data_init: Initialize the run queue
 178  */
 179
 180 int
 181 priv_data_init(struct v3_vm_info *vm){
 182
 183     PrintDebug(vm, VCORE_NONE,"EDF Sched. Initializing EDF Scheduling \n");
 184
 185     vm->sched_priv_data = V3_Malloc( vm->avail_cores * sizeof(struct vm_edf_rq));
 186
 187     if (!vm->sched_priv_data) {
 188         PrintError(vm, VCORE_NONE,"Cannot allocate in priv_data in priv_data_init\n");
 189         return -1;
 190     }
 191
 192     int lcore = 0;
 193
 194     PrintDebug(vm, VCORE_NONE,"EDF Sched. priv_data_init. Available cores %d\n", vm->avail_cores);
 195
 196     for(lcore = 0; lcore < vm->avail_cores ; lcore++){
 197
 198         PrintDebug(vm, VCORE_NONE,"EDF Sched. priv_data_init. Initializing logical core %d\n", lcore);
 199
 200         struct vm_edf_rq * edf_rq_list =   (struct vm_edf_rq *)vm->sched_priv_data;
 201         struct vm_edf_rq * edf_rq = &edf_rq_list[lcore];
 202
 203         edf_rq->vCPUs_tree = RB_ROOT;
 204         edf_rq->cpu_u=0;
 205         edf_rq->nr_vCPU=0;
 206         edf_rq->curr_vCPU=NULL;
 207         edf_rq->last_sched_time=0;
 208         edf_rq->check_deadline_time=0;
 209         edf_rq->sched_low=0;
 210         edf_rq->smallest_period=0;
 211         edf_rq->start_time = 0;
 212         edf_rq->yielded=false;
 213         init_edf_config(&edf_rq->edf_config);
 214
 215     }
 216
 217    return 0;
 218
 219 }
 220
 221 /*
 222  * is_admissible_core: Decides if a core is admited to the red black tree according with
 223  * the admisibility formula.
 224  */
 225
 226 static bool
 227 is_admissible_core(struct vm_core_edf_sched * new_sched_core, struct vm_edf_rq *runqueue){
 228
 229     int curr_utilization = runqueue->cpu_u;
 230     int new_utilization = curr_utilization + (100 * new_sched_core->slice / new_sched_core->period);
 231     int cpu_percent = (runqueue->edf_config).cpu_percent;
 232
 233     if (new_utilization <= cpu_percent)
 234         return true;
 235     else
 236         return false;
 237
 238 return true;
 239 }
 240
 241
 242
 243 /*
 244  * insert_core_edf: Finds a place in the tree for a newly activated core, adds the node
 245  * and rebalaces the tree
 246  */
 247
 248 static bool
 249 insert_core_edf(struct vm_core_edf_sched *core, struct vm_edf_rq *runqueue){
 250
 251     struct rb_node **new_core = &(runqueue->vCPUs_tree.rb_node);
 252     struct rb_node *parent = NULL;
 253     struct vm_core_edf_sched *curr_core;
 254
 255     // Find out place in the tree for the new core
 256     while (*new_core) {
 257
 258         curr_core = container_of(*new_core, struct vm_core_edf_sched, node);
 259         parent = *new_core;
 260
 261         if (core->current_deadline < curr_core->current_deadline)
 262             new_core = &((*new_core)->rb_left);
 263         else if (core->current_deadline > curr_core->current_deadline)
 264             new_core = &((*new_core)->rb_right);
 265         else // Is Possible to have same current deadlines in both cores!
 266             return false;
 267     }
 268     // Add new node and rebalance tree.
 269     rb_link_node(&core->node, parent, new_core);
 270     v3_rb_insert_color(&core->node, &runqueue->vCPUs_tree);
 271
 272     return true;
 273  }
 274
 275
 276 /*
 277  * get_curr_host_time: Calculates the current host time (microseconds)
 278  */
 279
 280 static uint64_t
 281 get_curr_host_time(struct vm_core_time *core_time){
 282
 283     uint64_t cur_cycle = v3_get_host_time(core_time);
 284     uint64_t cpu_khz = core_time->host_cpu_freq;
 285     uint64_t curr_time_us = 1000 * cur_cycle / cpu_khz;
 286
 287     return curr_time_us;
 288
 289 }
 290
 291
 292 /*
 293  * count_cores: Function useful to count the number of cores in a runqueue (Not used for now)
 294  *
 295  */
 296
 297 /*
 298 static int count_cores(struct vm_edf_rq *runqueue){
 299
 300   struct rb_node *node = v3_rb_first(&runqueue->vCPUs_tree);
 301   struct vm_core_edf_sched *curr_core;
 302   int number_cores = 0;
 303
 304     while(node){
 305
 306         number_cores++;
 307         curr_core = container_of(node, struct vm_core_edf_sched, node);
 308         time_us host_time =  get_curr_host_time(&curr_core->info->time_state);
 309         PrintDebug(VM_NONE,VCORE_NONE,"Count %d. core %d, used time %llu, deadline %llu, host time  %llu extra_time %llu\n",
 310                    number_cores,
 311                    curr_core->info->vcpu_id,
 312                    curr_core->used_time,
 313                    curr_core->current_deadline,
 314                    host_time,
 315                    curr_core->extra_time_given);
 316         node = v3_rb_next(node);
 317
 318     }
 319
 320    return number_cores;
 321 }
 322 */
 323
 324 /*
 325  * next_start_period: Given the current host time and the period of a given vCPU,
 326  * calculates the time in which its next period starts.
 327  *
 328  */
 329
 330 static uint64_t
 331 next_start_period(uint64_t curr_time_us, uint64_t period_us){
 332
 333     uint64_t time_period_us = curr_time_us % period_us;
 334     uint64_t remaining_time_us = period_us - time_period_us;
 335     uint64_t next_start_us = curr_time_us + remaining_time_us;
 336
 337     return next_start_us;
 338
 339 }
 340
 341 /*
 342  * get_runqueue: Get the runqueue assigned to a virtual core.
 343  */
 344
 345 struct vm_edf_rq * get_runqueue(struct guest_info *info){
 346
 347     struct vm_edf_rq *runqueue_list = (struct vm_edf_rq *) info->vm_info->sched_priv_data;
 348     struct vm_edf_rq *runqueue = &runqueue_list[info->pcpu_id];
 349     return runqueue;
 350 }
 351
 352
 353 /*
 354  * wakeup_core: Wakeup a given vCPU thread
 355  */
 356
 357 static void
 358 wakeup_core(struct guest_info *info){
 359
 360     struct vm_core_edf_sched *core = info->sched_priv_data;
 361     struct vm_edf_rq *runqueue = get_runqueue(info);
 362     time_us host_time = get_curr_host_time(&core->info->time_state);
 363
 364     if (!info->core_thread) {
 365               PrintError(info->vm_info, info,"ERROR: Tried to wakeup non-existent core thread vCPU_id %d \n",info->vcpu_id);
 366     }
 367     else {
 368
 369        V3_Wakeup(info->core_thread);
 370        if(core->start_time == 0){
 371             core->start_time = host_time;
 372             print_parameters(host_time, runqueue, core);
 373        }
 374        core->last_wakeup_time = host_time;
 375        runqueue->curr_vCPU = core;
 376
 377     }
 378
 379 }
 380
 381
 382 /*
 383  * activate_core - Moves a core to the red-black tree.
 384  * used time is set to zero and current deadline is calculated
 385  */
 386
 387 static int
 388 activate_core(struct vm_core_edf_sched * core, struct vm_edf_rq *runqueue){
 389
 390
 391     if (is_admissible_core(core, runqueue)){
 392
 393         uint64_t curr_time_us = get_curr_host_time(&core->info->time_state);
 394         uint64_t curr_deadline = next_start_period(curr_time_us, core->period);
 395
 396         core->current_deadline = curr_deadline;
 397         core->used_time=0;
 398
 399         bool ins = insert_core_edf(core, runqueue);
 400         /*
 401          * If not inserted is possible that there is other core with the same deadline.
 402          * Then, the deadline is modified and try again
 403          */
 404         while(!ins){
 405             core->current_deadline ++;
 406             ins = insert_core_edf(core, runqueue);
 407         }
 408
 409         runqueue->cpu_u += 100 * core->slice / core->period;
 410         runqueue->nr_vCPU ++;
 411
 412         if(runqueue->nr_vCPU == 1){
 413             runqueue->smallest_period = core->period;
 414         }
 415
 416         else if(core->period < runqueue->smallest_period){
 417           runqueue->smallest_period = core->period;
 418         }
 419
 420
 421         /*
 422          * If this is the first time to be activated pick first earliest deadline core to wakeup.
 423          */
 424
 425          if(!runqueue->curr_vCPU){
 426
 427             struct vm_core_edf_sched *next_core;
 428            // Pick first earliest deadline core
 429
 430             struct rb_node *node = v3_rb_first(&runqueue->vCPUs_tree);
 431             next_core = container_of(node, struct vm_core_edf_sched, node);
 432
 433             PrintDebug(VM_NONE, VCORE_NONE,"EDF Sched. First time activation, core %d, time %llu \n", next_core->info->vcpu_id, curr_time_us);
 434
 435             // Wakeup next_core (It is not neccessary to wakeup since in this case this is the first core launched by Palacios
 436             // however wakeup_core is called to initialize some needed parameters.
 437
 438             wakeup_core(next_core->info);
 439             next_core->start_time =  get_curr_host_time(&next_core->info->time_state);
 440             print_parameters(curr_time_us, runqueue, next_core);
 441             runqueue->start_time = next_core->start_time;
 442
 443
 444         }
 445
 446       }
 447       else
 448           PrintError(core->info->vm_info, core->info,"EDF Sched. activate_core. CPU cannot activate the core. It is not admissible");
 449     return 0;
 450
 451 }
 452
 453
 454 /*
 455  * edf_sched_core_init: Initializes per core data structure and
 456  * calls activate function.
 457  */
 458
 459
 460 int
 461 edf_sched_core_init(struct guest_info * info){
 462
 463     struct vm_edf_rq *runqueue = get_runqueue(info);
 464     struct vm_core_edf_sched *core_edf;
 465     struct v3_time *vm_ts = &(info->vm_info->time_state);
 466     uint32_t tdf = vm_ts->td_denom;
 467     uint_t cpu_khz = V3_CPU_KHZ();
 468
 469     PrintDebug(info->vm_info, info,"EDF Sched. Initializing vcore %d, tdf %d\n", info->vcpu_id,tdf);
 470
 471     core_edf = (struct vm_core_edf_sched *) V3_Malloc(sizeof (struct vm_core_edf_sched));
 472     if (!core_edf) {
 473         PrintError(info->vm_info, info,"Cannot allocate private_data in edf_sched_core_init\n");
 474         return -1;
 475     }
 476     info->sched_priv_data = core_edf;
 477
 478     // Default configuration if not specified in configuration file
 479
 480     core_edf->info = info;
 481     core_edf->period = MIN_PERIOD;
 482     core_edf->slice = MIN_SLICE;
 483     core_edf->used_time = 0;
 484     core_edf->last_wakeup_time = 0;
 485     core_edf->remaining_time = 0;
 486     core_edf->deadline = 0;
 487     core_edf->miss_deadline = 0;
 488     core_edf->extra_time = true;
 489     core_edf->total_time = 0;
 490     core_edf->slice_overuse = 0;
 491     core_edf->extra_time_given = 0;
 492     core_edf->expected_time = 0;
 493     core_edf->start_time = 0;
 494     core_edf->deadline_interval = 0;
 495     core_edf->deadline_percentage_interval = 0;
 496     core_edf->miss_deadline_interval = 0;
 497     core_edf->print_deadline_interval = 0;
 498
 499
 500     v3_cfg_tree_t * cfg_tree = core_edf->info->vm_info->cfg_data->cfg;
 501     v3_cfg_tree_t * core = v3_cfg_subtree(v3_cfg_subtree(cfg_tree, "cores"), "core");
 502
 503     while (core){
 504         char *id = v3_cfg_val(core, "vcpu_id");
 505         char *period = v3_cfg_val(core, "period");
 506         char *slice = v3_cfg_val(core, "slice");
 507         char *extra_time = v3_cfg_val(core, "extra_time");
 508         char *speed = v3_cfg_val(core, "khz");
 509         uint_t speed_khz = cpu_khz;
 510
 511         if (atoi(id) == core_edf->info->vcpu_id){
 512
 513             if(speed){
 514                 speed_khz = atoi(speed);
 515             }
 516
 517             if(slice){
 518                 core_edf->slice = atoi(slice);
 519             }
 520             else{
 521                 core_edf->slice = MIN_SLICE;
 522             }
 523
 524             if(period){
 525                 core_edf->period = atoi(period);
 526             }
 527             else{
 528                 core_edf->period = (core_edf->slice * cpu_khz * tdf)/speed_khz;
 529                 core_edf->period += 0.3*(100*core_edf->slice/core_edf->period); // Give faster vcores a little more bigger periods.
 530             }
 531
 532             PrintDebug(info->vm_info,info,"EDF_SCHED. Vcore %d, Pcore %d, cpu_khz %u, Period %llu Speed %d, Utilization %d, tdf %d %llu \n",
 533                    core_edf->info->vcpu_id,
 534                    core_edf->info->pcpu_id,
 535                    cpu_khz,
 536                    core_edf->period,
 537                    speed_khz,
 538                    (int)(100*core_edf->slice/core_edf->period),
 539                    tdf,
 540                    runqueue->smallest_period);
 541
 542             if(extra_time){
 543                 if (strcasecmp(extra_time, "true") == 0)
 544                     core_edf->extra_time = true;
 545                 else
 546                     core_edf->extra_time = false;
 547             }
 548             else
 549                 core_edf->extra_time = false;
 550
 551             break;
 552         }
 553         core = v3_cfg_next_branch(core);
 554     }
 555
 556     return activate_core(core_edf,runqueue);
 557
 558 }
 559
 560
 561 /*
 562  * search_core_edf: Searches a core in the red-black tree by using its current_deadline
 563  */
 564 static struct vm_core_edf_sched *
 565 search_core_edf(time_us current_deadline, struct vm_edf_rq *runqueue){
 566
 567     struct rb_node *node = runqueue->vCPUs_tree.rb_node;
 568
 569     while (node) {
 570         struct vm_core_edf_sched *core = container_of(node, struct vm_core_edf_sched, node);
 571
 572         if (current_deadline < core->current_deadline)
 573             node = node->rb_left;
 574         else if (current_deadline > core->current_deadline)
 575             node = node->rb_right;
 576         else
 577             return core;
 578     }
 579     return NULL;
 580 }
 581
 582
 583 /*
 584  * delete_core_edf: Deletes a core from the red black tree, generally when it has
 585  * consumed its time slice within the current period.
 586  */
 587
 588 static bool
 589 delete_core_edf( struct vm_core_edf_sched *core_edf  , struct vm_edf_rq *runqueue){
 590
 591     struct vm_core_edf_sched *core = search_core_edf(core_edf->current_deadline, runqueue);
 592         if (core){
 593
 594             v3_rb_erase(&core->node, &runqueue->vCPUs_tree);
 595             return true;
 596         }
 597         else{
 598             PrintError(VM_NONE,VCORE_NONE,"EDF Sched. delete_core_edf.Attempted to erase unexisting core");
 599             return false;
 600         }
 601 }
 602
 603
 604 /*
 605  * deactivate_core - Removes a core from the red-black tree.
 606  */
 607
 608 static void
 609 deactivate_core(struct vm_core_edf_sched * core, struct vm_edf_rq *runqueue){
 610
 611      if(delete_core_edf(core, runqueue)){
 612          runqueue->cpu_u -= 100 * core->slice / core->period;
 613          runqueue->nr_vCPU -- ;
 614      }
 615 }
 616
 617 /*
 618  * adjust_slice - Adjust vcore parameters values
 619  */
 620
 621 static void adjust_slice(struct vm_core_edf_sched *core){
 622
 623     time_us host_time = get_curr_host_time(&core->info->time_state);
 624     time_us used_time =  host_time - core->last_wakeup_time;
 625
 626     if(core->last_wakeup_time != 0){
 627
 628         core->used_time += used_time;
 629         core->total_time += used_time;
 630         if(core->start_time != 0){
 631             core->expected_time = ((host_time - core->start_time)/core->period)*core->slice;
 632         }
 633         if(core->total_time <= core->expected_time){
 634             core->remaining_time = core->expected_time - core->total_time;
 635         }
 636         else{
 637             core->remaining_time =0;
 638         }
 639
 640         if (core->used_time > core->slice){
 641             core->slice_overuse++;
 642         }
 643     }
 644
 645 }
 646
 647 /*
 648  * Check_deadlines - Check virtual cores, and re-insert in the runqueue the ones which deadline is over
 649  */
 650
 651
 652 static void check_deadlines(struct vm_edf_rq *runqueue){
 653
 654     struct rb_node *node = v3_rb_first(&runqueue->vCPUs_tree);
 655     struct vm_core_edf_sched *next_core = container_of(node, struct vm_core_edf_sched, node);
 656     time_us host_time = get_curr_host_time(&next_core->info->time_state);
 657     struct vm_core_edf_sched * deadline_cores[runqueue->nr_vCPU];
 658
 659
 660     int nr_dcores=0;
 661     int i=0;
 662     memset(deadline_cores, 0, runqueue->nr_vCPU);
 663
 664     while(node){
 665
 666         next_core = container_of(node, struct vm_core_edf_sched, node);
 667         if(next_core->current_deadline < host_time){
 668             next_core->deadline++;
 669             next_core->deadline_interval++;
 670             deadline_cores[nr_dcores++]= next_core;
 671             if(next_core->used_time < next_core->slice){
 672                 next_core->miss_deadline++;
 673                 next_core->miss_deadline_interval++;
 674
 675                 /*PrintError(VM_NONE,VCORE_NONE,"Test: Core %d miss_deadlines %d, used time %llu, slice %llu, deadline %llu, host time %llu \n",
 676                        next_core->info->vcpu_id,
 677                        next_core->miss_deadline,
 678                        next_core->used_time,
 679                        next_core->slice,
 680                        next_core->current_deadline,
 681                        host_time);*/
 682
 683             }
 684             else{
 685               next_core->extra_time_given += (next_core->used_time - next_core->slice);
 686
 687               /* PrintError(VM_NONE,VCORE_NONE,"Test: Extra time, core %d, core used time %llu, slice %llu, extra time %llu, Total extra time %llu \n",
 688                  next_core->info->vcpu_id,
 689                  next_core->used_time,
 690                  next_core->slice,
 691                  (next_core->used_time - next_core->slice),
 692                  next_core->extra_time_given);*/
 693
 694             }
 695
 696         }
 697         else{
 698             break;
 699         }
 700         node = v3_rb_next(node);
 701     }
 702
 703
 704     for(i=0;i<nr_dcores;i++){
 705
 706         next_core = deadline_cores[nr_dcores-1-i];
 707
 708         deactivate_core(next_core,runqueue);
 709         activate_core(next_core,runqueue);
 710
 711     }
 712     runqueue->check_deadline_time = host_time;
 713 }
 714
 715
 716
 717 /*
 718  * pick_next_core: Returns the next core to be scheduled from the red black tree
 719  */
 720
 721 static struct vm_core_edf_sched *
 722 pick_next_core(struct vm_edf_rq *runqueue){
 723
 724     /*
 725      * Pick first earliest deadline core
 726      */
 727     struct rb_node *node=NULL;
 728     struct vm_core_edf_sched *next_core=NULL;
 729     time_us core_deadline=0;         // Deadline of the core with more time remaining
 730     time_us core_extra_deadline=0;   // Deadline of the core with extra time enable and earliest deadline
 731     time_us max_remaining=0;
 732     time_us host_time = get_curr_host_time(&runqueue->curr_vCPU->info->time_state);
 733
 734     if(host_time - runqueue->check_deadline_time >= runqueue->smallest_period ){
 735         check_deadlines(runqueue);
 736     }
 737
 738     node = v3_rb_first(&runqueue->vCPUs_tree);
 739     next_core = container_of(node, struct vm_core_edf_sched, node);
 740
 741     if (next_core->used_time < next_core->slice){
 742          return next_core;
 743     }
 744
 745     if(next_core->total_time < next_core->expected_time){
 746         max_remaining = next_core->remaining_time;
 747         core_deadline = next_core->current_deadline;
 748     }
 749
 750     if(next_core->extra_time){
 751         core_extra_deadline = next_core->current_deadline;
 752     }
 753
 754     // Pick the next core that has not used its whole slice
 755     while(node){
 756
 757         next_core = container_of(node, struct vm_core_edf_sched, node);
 758
 759         if(next_core->remaining_time > max_remaining){
 760             max_remaining = next_core->extra_time_given;
 761             core_deadline = next_core->current_deadline;
 762             if(core_extra_deadline !=0 && next_core->extra_time){
 763                 core_extra_deadline = next_core->current_deadline;
 764             }
 765         }
 766
 767         if(next_core->used_time < next_core->slice){
 768           return next_core;
 769         }
 770
 771
 772         node = v3_rb_next(node);
 773     }
 774
 775     if(core_extra_deadline !=0){
 776         next_core  = search_core_edf(core_extra_deadline, runqueue);
 777     }
 778
 779     else if (core_deadline != 0){
 780         next_core  = search_core_edf(core_deadline, runqueue);
 781     }
 782
 783      return NULL;
 784 }
 785
 786
 787 /*
 788  * run_next_core: Pick next core to be scheduled and wakeup it
 789  */
 790
 791 static void
 792 run_next_core(struct guest_info *info, int usec)
 793 {
 794     struct vm_core_edf_sched *core = info->sched_priv_data;
 795     struct vm_core_edf_sched *next_core;
 796     struct vm_edf_rq *runqueue = get_runqueue(info);
 797     time_us host_time = get_curr_host_time(&info->time_state);
 798
 799      /* The next core to be scheduled is choosen from the tree (Function pick_next_core).
 800      * The selected core is the one with the earliest deadline and with available time
 801      * to use within the current period (used_time < slice)
 802      */
 803     if(!runqueue->yielded){
 804         adjust_slice(core);
 805     }
 806     next_core = pick_next_core(runqueue); // Pick next core to schedule
 807
 808     if(host_time - core->print_deadline_interval >= DEADLINE_INTERVAL){
 809
 810         if(core->deadline_interval != 0){
 811             core->deadline_percentage_interval = (int)100*core->miss_deadline_interval/core->deadline_interval;
 812         }
 813
 814         PrintDebug(info->vm_info,info,"deadline: %d %llu %llu %d",
 815             core->info->vcpu_id,
 816             core->deadline_interval,
 817             core->miss_deadline_interval,
 818             core->deadline_percentage_interval);
 819
 820         core->print_deadline_interval = host_time;
 821         core->deadline_interval=0;
 822         core->miss_deadline_interval = 0;
 823         core->deadline_percentage_interval = 0;
 824     }
 825
 826     if(!next_core){
 827         runqueue->yielded=true;
 828         V3_Yield();
 829         return;
 830     }
 831     runqueue->yielded=false;
 832
 833
 834     if(core->deadline != 0)
 835         core->deadline_percentage = (int)100*core->miss_deadline/core->deadline;
 836
 837     if (core != next_core){
 838
 839         print_parameters(host_time, runqueue,core);
 840         wakeup_core(next_core->info);
 841         V3_Sleep(usec);
 842      }
 843
 844     else{
 845         // Necessary to update last_wakeup_time to adjust slice properly later
 846         next_core->last_wakeup_time = get_curr_host_time(&next_core->info->time_state);
 847
 848         if(host_time - runqueue->print_time >= runqueue->smallest_period ){
 849             print_parameters(host_time, runqueue,core);
 850         }
 851      }
 852
 853 }
 854
 855
 856 /*
 857  * edf_schedule: Scheduling function
 858  */
 859
 860 static void
 861 edf_schedule(struct guest_info * info, int usec){
 862
 863   uint64_t host_time = get_curr_host_time(&info->time_state);
 864   struct vm_edf_rq *runqueue = get_runqueue(info);
 865
 866   /*PrintDebug(info->vm_info,info,"Test PCORE. %d host time: %llu Last sched_time: %llu, difference: %llu\n",
 867     info->pcpu_id,  host_time, runqueue->last_sched_time, host_time-runqueue->last_sched_time); */
 868
 869   /* if( (runqueue->last_sched_time !=0) && ((host_time - runqueue->last_sched_time) > 10000)){
 870          PrintDebug(info->vm_info,info,"%d Test PCORE. %d LOW SCHED FREQUENCY  host time: %llu Last sched_time: %llu, difference: %llu\n",
 871                  ++runqueue->sched_low,info->pcpu_id,  host_time, runqueue->last_sched_time, host_time-runqueue->last_sched_time);
 872                  }*/
 873
 874   runqueue->last_sched_time = host_time;
 875   run_next_core(info, usec);
 876     return;
 877
 878 }
 879
 880 /*
 881  * edf_sched_schedule: Main scheduling function. Called each time that an interruption occurs.
 882  *
 883  */
 884
 885 void
 886 edf_sched_schedule(struct guest_info * info){
 887
 888     edf_schedule(info, 0);
 889     return;
 890 }
 891
 892 /*
 893  * edf_sched_yield: Called when yielding the logical cpu for usec is needed
 894  */
 895
 896 void
 897 edf_sched_yield(struct guest_info * info, int usec){
 898     edf_schedule(info, usec);
 899     return;
 900 }
 901
 902 /*
 903  * edf_sched_core_stop. Stops virtual machine. All the virtual cores yield the CPU
 904  */
 905
 906 int
 907 edf_sched_core_stop(struct guest_info * info){
 908
 909     struct vm_edf_rq * runqueue =  get_runqueue(info);
 910     struct rb_node *node = v3_rb_first(&runqueue->vCPUs_tree);
 911     struct vm_core_edf_sched *curr_core;
 912
 913     while(node){
 914
 915         curr_core = container_of(node, struct vm_core_edf_sched, node);
 916         wakeup_core(curr_core->info);
 917         PrintDebug(VM_NONE,VCORE_NONE,"Waking up core %d, thread (%p)\n",
 918                    curr_core->info->vcpu_id,
 919                  (struct task_struct *)info->core_thread);
 920         V3_Yield();
 921         PrintDebug(VM_NONE,VCORE_NONE,"Yielding Thread %p\n",(struct task_struct *)info->core_thread);
 922         node = v3_rb_next(node);
 923
 924     }
 925    return 0;
 926 }
 927
 928
 929 /*
 930  * edf_sched_deinit: Frees edf scheduler data structures
 931  */
 932
 933
 934 int
 935 edf_sched_deinit(struct v3_vm_info *vm)
 936 {
 937     PrintDebug(VM_NONE,VCORE_NONE,"Freeing vm\n");
 938     void *priv_data = vm->sched_priv_data;
 939
 940     if (priv_data)
 941         V3_Free(priv_data);
 942
 943     return 0;
 944
 945 }
 946
 947 /*
 948  * edf_sched_deinit: Frees virtual core data structures
 949  */
 950
 951 int
 952 edf_sched_core_deinit(struct guest_info *core)
 953 {
 954     PrintDebug(VM_NONE,VCORE_NONE,"Freeing core\n");
 955     void *priv_data = core->sched_priv_data;
 956
 957     if (priv_data)
 958         V3_Free(priv_data);
 959
 960     return 0;
 961 }
 962
 963 /*
 964  * edf_sched_vm_int. Called when the VM starts
 965  */
 966
 967 int edf_sched_vm_init(struct v3_vm_info *vm){
 968     return 0;
 969 }
 970
 971 int edf_sched_admit(struct v3_vm_info *vm){
 972
 973     /*
 974      * Initialize priv_data for the vm:
 975      * For EDF this is done here because we need the parameter
 976      * avail_core which is set in v3_start_vm before the
 977      * v3_scheduler_admit_vm function is called.
 978      */
 979
 980     priv_data_init(vm);
 981
 982     // TODO Admission
 983
 984     return 0;
 985 }
 986
 987
 988 /*
 989  * vm_scheduler_impl. Functions that implement vmm_scheduler interface
 990  */
 991
 992 static struct vm_scheduler_impl edf_sched = {
 993
 994     .name = "edf",
 995     .init = NULL,
 996     .deinit = NULL,
 997     .vm_init = edf_sched_vm_init,
 998     .vm_deinit = edf_sched_deinit,
 999     .core_init = edf_sched_core_init,
1000     .core_stop = edf_sched_core_stop,
1001     .core_deinit = edf_sched_core_deinit,
1002     .schedule = edf_sched_schedule,
1003     .yield = edf_sched_yield,
1004     .admit = edf_sched_admit,
1005     .remap = NULL,
1006     .dvfs=NULL
1007 };
1008
1009
1010 /*
1011  * ext_sched_edf_init. Creates an register the EDF scheduler.
1012  */
1013
1014 static int
1015 ext_sched_edf_init() {
1016     PrintDebug(VM_NONE, VCORE_NONE,"Sched. Creating (%s) scheduler\n",edf_sched.name);
1017     return v3_register_scheduler(&edf_sched);
1018 }
1019
1020 /*
1021  * ext_sched_edf_vm_int. Called when the VM starts
1022  */
1023
1024 static int
1025 ext_sched_edf_vm_init() {
1026     return 0;
1027 }
1028
1029
1030 /*
1031  * v3_extension_impl. EDF extension functions
1032  */
1033
1034
1035 static struct v3_extension_impl sched_edf_impl = {
1036         .name = "EDF Scheduler",
1037         .init = ext_sched_edf_init,
1038         .vm_init = ext_sched_edf_vm_init,
1039         .vm_deinit = NULL,
1040         .core_init = NULL,
1041         .core_deinit = NULL,
1042         .on_entry = NULL,
1043         .on_exit = NULL
1044 };
1045
1046 register_extension(&sched_edf_impl);