examples/performance-thread/common/lthread_sched.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2015 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Some portions of this software is derived from the
  36  * https://github.com/halayli/lthread which carrys the following license.
  37  *
  38  * Copyright (C) 2012, Hasan Alayli <halayli@gmail.com>
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  */
  61
  62
  63 #define RTE_MEM 1
  64
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #include <stdint.h>
  69 #include <stddef.h>
  70 #include <limits.h>
  71 #include <inttypes.h>
  72 #include <unistd.h>
  73 #include <pthread.h>
  74 #include <fcntl.h>
  75 #include <sys/time.h>
  76 #include <sys/mman.h>
  77 #include <sched.h>
  78
  79 #include <rte_prefetch.h>
  80 #include <rte_per_lcore.h>
  81 #include <rte_atomic.h>
  82 #include <rte_atomic_64.h>
  83 #include <rte_log.h>
  84 #include <rte_common.h>
  85 #include <rte_branch_prediction.h>
  86
  87 #include "lthread_api.h"
  88 #include "lthread_int.h"
  89 #include "lthread_sched.h"
  90 #include "lthread_objcache.h"
  91 #include "lthread_timer.h"
  92 #include "lthread_mutex.h"
  93 #include "lthread_cond.h"
  94 #include "lthread_tls.h"
  95 #include "lthread_diag.h"
  96
  97 /*
  98  * This file implements the lthread scheduler
  99  * The scheduler is the function lthread_run()
 100  * This must be run as the main loop of an EAL thread.
 101  *
 102  * Currently once a scheduler is created it cannot be destroyed
 103  * When a scheduler shuts down it is assumed that the application is terminating
 104  */
 105
 106 static rte_atomic16_t num_schedulers;
 107 static rte_atomic16_t active_schedulers;
 108
 109 /* one scheduler per lcore */
 110 RTE_DEFINE_PER_LCORE(struct lthread_sched *, this_sched) = NULL;
 111
 112 struct lthread_sched *schedcore[LTHREAD_MAX_LCORES];
 113
 114 diag_callback diag_cb;
 115
 116 uint64_t diag_mask;
 117
 118
 119 /* constructor */
 120 RTE_INIT(lthread_sched_ctor)
 121 {
 122         memset(schedcore, 0, sizeof(schedcore));
 123         rte_atomic16_init(&num_schedulers);
 124         rte_atomic16_set(&num_schedulers, 1);
 125         rte_atomic16_init(&active_schedulers);
 126         rte_atomic16_set(&active_schedulers, 0);
 127         diag_cb = NULL;
 128 }
 129
 130
 131 enum sched_alloc_phase {
 132         SCHED_ALLOC_OK,
 133         SCHED_ALLOC_QNODE_POOL,
 134         SCHED_ALLOC_READY_QUEUE,
 135         SCHED_ALLOC_PREADY_QUEUE,
 136         SCHED_ALLOC_LTHREAD_CACHE,
 137         SCHED_ALLOC_STACK_CACHE,
 138         SCHED_ALLOC_PERLT_CACHE,
 139         SCHED_ALLOC_TLS_CACHE,
 140         SCHED_ALLOC_COND_CACHE,
 141         SCHED_ALLOC_MUTEX_CACHE,
 142 };
 143
 144 static int
 145 _lthread_sched_alloc_resources(struct lthread_sched *new_sched)
 146 {
 147         int alloc_status;
 148
 149         do {
 150                 /* Initialize per scheduler queue node pool */
 151                 alloc_status = SCHED_ALLOC_QNODE_POOL;
 152                 new_sched->qnode_pool =
 153                         _qnode_pool_create("qnode pool", LTHREAD_PREALLOC);
 154                 if (new_sched->qnode_pool == NULL)
 155                         break;
 156
 157                 /* Initialize per scheduler local ready queue */
 158                 alloc_status = SCHED_ALLOC_READY_QUEUE;
 159                 new_sched->ready = _lthread_queue_create("ready queue");
 160                 if (new_sched->ready == NULL)
 161                         break;
 162
 163                 /* Initialize per scheduler local peer ready queue */
 164                 alloc_status = SCHED_ALLOC_PREADY_QUEUE;
 165                 new_sched->pready = _lthread_queue_create("pready queue");
 166                 if (new_sched->pready == NULL)
 167                         break;
 168
 169                 /* Initialize per scheduler local free lthread cache */
 170                 alloc_status = SCHED_ALLOC_LTHREAD_CACHE;
 171                 new_sched->lthread_cache =
 172                         _lthread_objcache_create("lthread cache",
 173                                                 sizeof(struct lthread),
 174                                                 LTHREAD_PREALLOC);
 175                 if (new_sched->lthread_cache == NULL)
 176                         break;
 177
 178                 /* Initialize per scheduler local free stack cache */
 179                 alloc_status = SCHED_ALLOC_STACK_CACHE;
 180                 new_sched->stack_cache =
 181                         _lthread_objcache_create("stack_cache",
 182                                                 sizeof(struct lthread_stack),
 183                                                 LTHREAD_PREALLOC);
 184                 if (new_sched->stack_cache == NULL)
 185                         break;
 186
 187                 /* Initialize per scheduler local free per lthread data cache */
 188                 alloc_status = SCHED_ALLOC_PERLT_CACHE;
 189                 new_sched->per_lthread_cache =
 190                         _lthread_objcache_create("per_lt cache",
 191                                                 RTE_PER_LTHREAD_SECTION_SIZE,
 192                                                 LTHREAD_PREALLOC);
 193                 if (new_sched->per_lthread_cache == NULL)
 194                         break;
 195
 196                 /* Initialize per scheduler local free tls cache */
 197                 alloc_status = SCHED_ALLOC_TLS_CACHE;
 198                 new_sched->tls_cache =
 199                         _lthread_objcache_create("TLS cache",
 200                                                 sizeof(struct lthread_tls),
 201                                                 LTHREAD_PREALLOC);
 202                 if (new_sched->tls_cache == NULL)
 203                         break;
 204
 205                 /* Initialize per scheduler local free cond var cache */
 206                 alloc_status = SCHED_ALLOC_COND_CACHE;
 207                 new_sched->cond_cache =
 208                         _lthread_objcache_create("cond cache",
 209                                                 sizeof(struct lthread_cond),
 210                                                 LTHREAD_PREALLOC);
 211                 if (new_sched->cond_cache == NULL)
 212                         break;
 213
 214                 /* Initialize per scheduler local free mutex cache */
 215                 alloc_status = SCHED_ALLOC_MUTEX_CACHE;
 216                 new_sched->mutex_cache =
 217                         _lthread_objcache_create("mutex cache",
 218                                                 sizeof(struct lthread_mutex),
 219                                                 LTHREAD_PREALLOC);
 220                 if (new_sched->mutex_cache == NULL)
 221                         break;
 222
 223                 alloc_status = SCHED_ALLOC_OK;
 224         } while (0);
 225
 226         /* roll back on any failure */
 227         switch (alloc_status) {
 228         case SCHED_ALLOC_MUTEX_CACHE:
 229                 _lthread_objcache_destroy(new_sched->cond_cache);
 230                 /* fall through */
 231         case SCHED_ALLOC_COND_CACHE:
 232                 _lthread_objcache_destroy(new_sched->tls_cache);
 233                 /* fall through */
 234         case SCHED_ALLOC_TLS_CACHE:
 235                 _lthread_objcache_destroy(new_sched->per_lthread_cache);
 236                 /* fall through */
 237         case SCHED_ALLOC_PERLT_CACHE:
 238                 _lthread_objcache_destroy(new_sched->stack_cache);
 239                 /* fall through */
 240         case SCHED_ALLOC_STACK_CACHE:
 241                 _lthread_objcache_destroy(new_sched->lthread_cache);
 242                 /* fall through */
 243         case SCHED_ALLOC_LTHREAD_CACHE:
 244                 _lthread_queue_destroy(new_sched->pready);
 245                 /* fall through */
 246         case SCHED_ALLOC_PREADY_QUEUE:
 247                 _lthread_queue_destroy(new_sched->ready);
 248                 /* fall through */
 249         case SCHED_ALLOC_READY_QUEUE:
 250                 _qnode_pool_destroy(new_sched->qnode_pool);
 251                 /* fall through */
 252         case SCHED_ALLOC_QNODE_POOL:
 253                 /* fall through */
 254         case SCHED_ALLOC_OK:
 255                 break;
 256         }
 257         return alloc_status;
 258 }
 259
 260
 261 /*
 262  * Create a scheduler on the current lcore
 263  */
 264 struct lthread_sched *_lthread_sched_create(size_t stack_size)
 265 {
 266         int status;
 267         struct lthread_sched *new_sched;
 268         unsigned lcoreid = rte_lcore_id();
 269
 270         RTE_ASSERT(stack_size <= LTHREAD_MAX_STACK_SIZE);
 271
 272         if (stack_size == 0)
 273                 stack_size = LTHREAD_MAX_STACK_SIZE;
 274
 275         new_sched =
 276              rte_calloc_socket(NULL, 1, sizeof(struct lthread_sched),
 277                                 RTE_CACHE_LINE_SIZE,
 278                                 rte_socket_id());
 279         if (new_sched == NULL) {
 280                 RTE_LOG(CRIT, LTHREAD,
 281                         "Failed to allocate memory for scheduler\n");
 282                 return NULL;
 283         }
 284
 285         _lthread_key_pool_init();
 286
 287         new_sched->stack_size = stack_size;
 288         new_sched->birth = rte_rdtsc();
 289         THIS_SCHED = new_sched;
 290
 291         status = _lthread_sched_alloc_resources(new_sched);
 292         if (status != SCHED_ALLOC_OK) {
 293                 RTE_LOG(CRIT, LTHREAD,
 294                         "Failed to allocate resources for scheduler code = %d\n",
 295                         status);
 296                 rte_free(new_sched);
 297                 return NULL;
 298         }
 299
 300         bzero(&new_sched->ctx, sizeof(struct ctx));
 301
 302         new_sched->lcore_id = lcoreid;
 303
 304         schedcore[lcoreid] = new_sched;
 305
 306         new_sched->run_flag = 1;
 307
 308         DIAG_EVENT(new_sched, LT_DIAG_SCHED_CREATE, rte_lcore_id(), 0);
 309
 310         rte_wmb();
 311         return new_sched;
 312 }
 313
 314 /*
 315  * Set the number of schedulers in the system
 316  */
 317 int lthread_num_schedulers_set(int num)
 318 {
 319         rte_atomic16_set(&num_schedulers, num);
 320         return (int)rte_atomic16_read(&num_schedulers);
 321 }
 322
 323 /*
 324  * Return the number of schedulers active
 325  */
 326 int lthread_active_schedulers(void)
 327 {
 328         return (int)rte_atomic16_read(&active_schedulers);
 329 }
 330
 331
 332 /**
 333  * shutdown the scheduler running on the specified lcore
 334  */
 335 void lthread_scheduler_shutdown(unsigned lcoreid)
 336 {
 337         uint64_t coreid = (uint64_t) lcoreid;
 338
 339         if (coreid < LTHREAD_MAX_LCORES) {
 340                 if (schedcore[coreid] != NULL)
 341                         schedcore[coreid]->run_flag = 0;
 342         }
 343 }
 344
 345 /**
 346  * shutdown all schedulers
 347  */
 348 void lthread_scheduler_shutdown_all(void)
 349 {
 350         uint64_t i;
 351
 352         /*
 353          * give time for all schedulers to have started
 354          * Note we use sched_yield() rather than pthread_yield() to allow
 355          * for the possibility of a pthread wrapper on lthread_yield(),
 356          * something that is not possible unless the scheduler is running.
 357          */
 358         while (rte_atomic16_read(&active_schedulers) <
 359                rte_atomic16_read(&num_schedulers))
 360                 sched_yield();
 361
 362         for (i = 0; i < LTHREAD_MAX_LCORES; i++) {
 363                 if (schedcore[i] != NULL)
 364                         schedcore[i]->run_flag = 0;
 365         }
 366 }
 367
 368 /*
 369  * Resume a suspended lthread
 370  */
 371 static __rte_always_inline void
 372 _lthread_resume(struct lthread *lt);
 373 static inline void _lthread_resume(struct lthread *lt)
 374 {
 375         struct lthread_sched *sched = THIS_SCHED;
 376         struct lthread_stack *s;
 377         uint64_t state = lt->state;
 378 #if LTHREAD_DIAG
 379         int init = 0;
 380 #endif
 381
 382         sched->current_lthread = lt;
 383
 384         if (state & (BIT(ST_LT_CANCELLED) | BIT(ST_LT_EXITED))) {
 385                 /* if detached we can free the thread now */
 386                 if (state & BIT(ST_LT_DETACH)) {
 387                         _lthread_free(lt);
 388                         sched->current_lthread = NULL;
 389                         return;
 390                 }
 391         }
 392
 393         if (state & BIT(ST_LT_INIT)) {
 394                 /* first time this thread has been run */
 395                 /* assign thread to this scheduler */
 396                 lt->sched = THIS_SCHED;
 397
 398                 /* allocate stack */
 399                 s = _stack_alloc();
 400
 401                 lt->stack_container = s;
 402                 _lthread_set_stack(lt, s->stack, s->stack_size);
 403
 404                 /* allocate memory for TLS used by this thread */
 405                 _lthread_tls_alloc(lt);
 406
 407                 lt->state = BIT(ST_LT_READY);
 408 #if LTHREAD_DIAG
 409                 init = 1;
 410 #endif
 411         }
 412
 413         DIAG_EVENT(lt, LT_DIAG_LTHREAD_RESUMED, init, lt);
 414
 415         /* switch to the new thread */
 416         ctx_switch(&lt->ctx, &sched->ctx);
 417
 418         /* If posting to a queue that could be read by another lcore
 419          * we defer the queue write till now to ensure the context has been
 420          * saved before the other core tries to resume it
 421          * This applies to blocking on mutex, cond, and to set_affinity
 422          */
 423         if (lt->pending_wr_queue != NULL) {
 424                 struct lthread_queue *dest = lt->pending_wr_queue;
 425
 426                 lt->pending_wr_queue = NULL;
 427
 428                 /* queue the current thread to the specified queue */
 429                 _lthread_queue_insert_mp(dest, lt);
 430         }
 431
 432         sched->current_lthread = NULL;
 433 }
 434
 435 /*
 436  * Handle sleep timer expiry
 437 */
 438 void
 439 _sched_timer_cb(struct rte_timer *tim, void *arg)
 440 {
 441         struct lthread *lt = (struct lthread *) arg;
 442         uint64_t state = lt->state;
 443
 444         DIAG_EVENT(lt, LT_DIAG_LTHREAD_TMR_EXPIRED, &lt->tim, 0);
 445
 446         rte_timer_stop(tim);
 447
 448         if (lt->state & BIT(ST_LT_CANCELLED))
 449                 (THIS_SCHED)->nb_blocked_threads--;
 450
 451         lt->state = state | BIT(ST_LT_EXPIRED);
 452         _lthread_resume(lt);
 453         lt->state = state & CLEARBIT(ST_LT_EXPIRED);
 454 }
 455
 456
 457
 458 /*
 459  * Returns 0 if there is a pending job in scheduler or 1 if done and can exit.
 460  */
 461 static inline int _lthread_sched_isdone(struct lthread_sched *sched)
 462 {
 463         return (sched->run_flag == 0) &&
 464                         (_lthread_queue_empty(sched->ready)) &&
 465                         (_lthread_queue_empty(sched->pready)) &&
 466                         (sched->nb_blocked_threads == 0);
 467 }
 468
 469 /*
 470  * Wait for all schedulers to start
 471  */
 472 static inline void _lthread_schedulers_sync_start(void)
 473 {
 474         rte_atomic16_inc(&active_schedulers);
 475
 476         /* wait for lthread schedulers
 477          * Note we use sched_yield() rather than pthread_yield() to allow
 478          * for the possibility of a pthread wrapper on lthread_yield(),
 479          * something that is not possible unless the scheduler is running.
 480          */
 481         while (rte_atomic16_read(&active_schedulers) <
 482                rte_atomic16_read(&num_schedulers))
 483                 sched_yield();
 484
 485 }
 486
 487 /*
 488  * Wait for all schedulers to stop
 489  */
 490 static inline void _lthread_schedulers_sync_stop(void)
 491 {
 492         rte_atomic16_dec(&active_schedulers);
 493         rte_atomic16_dec(&num_schedulers);
 494
 495         /* wait for schedulers
 496          * Note we use sched_yield() rather than pthread_yield() to allow
 497          * for the possibility of a pthread wrapper on lthread_yield(),
 498          * something that is not possible unless the scheduler is running.
 499          */
 500         while (rte_atomic16_read(&active_schedulers) > 0)
 501                 sched_yield();
 502
 503 }
 504
 505
 506 /*
 507  * Run the lthread scheduler
 508  * This loop is the heart of the system
 509  */
 510 void lthread_run(void)
 511 {
 512
 513         struct lthread_sched *sched = THIS_SCHED;
 514         struct lthread *lt = NULL;
 515
 516         RTE_LOG(INFO, LTHREAD,
 517                 "starting scheduler %p on lcore %u phys core %u\n",
 518                 sched, rte_lcore_id(),
 519                 rte_lcore_index(rte_lcore_id()));
 520
 521         /* if more than one, wait for all schedulers to start */
 522         _lthread_schedulers_sync_start();
 523
 524
 525         /*
 526          * This is the main scheduling loop
 527          * So long as there are tasks in existence we run this loop.
 528          * We check for:-
 529          *   expired timers,
 530          *   the local ready queue,
 531          *   and the peer ready queue,
 532          *
 533          * and resume lthreads ad infinitum.
 534          */
 535         while (!_lthread_sched_isdone(sched)) {
 536
 537                 rte_timer_manage();
 538
 539                 lt = _lthread_queue_poll(sched->ready);
 540                 if (lt != NULL)
 541                         _lthread_resume(lt);
 542                 lt = _lthread_queue_poll(sched->pready);
 543                 if (lt != NULL)
 544                         _lthread_resume(lt);
 545         }
 546
 547
 548         /* if more than one wait for all schedulers to stop */
 549         _lthread_schedulers_sync_stop();
 550
 551         (THIS_SCHED) = NULL;
 552
 553         RTE_LOG(INFO, LTHREAD,
 554                 "stopping scheduler %p on lcore %u phys core %u\n",
 555                 sched, rte_lcore_id(),
 556                 rte_lcore_index(rte_lcore_id()));
 557         fflush(stdout);
 558 }
 559
 560 /*
 561  * Return the scheduler for this lcore
 562  *
 563  */
 564 struct lthread_sched *_lthread_sched_get(unsigned int lcore_id)
 565 {
 566         struct lthread_sched *res = NULL;
 567
 568         if (lcore_id < LTHREAD_MAX_LCORES)
 569                 res = schedcore[lcore_id];
 570
 571         return res;
 572 }
 573
 574 /*
 575  * migrate the current thread to another scheduler running
 576  * on the specified lcore.
 577  */
 578 int lthread_set_affinity(unsigned lcoreid)
 579 {
 580         struct lthread *lt = THIS_LTHREAD;
 581         struct lthread_sched *dest_sched;
 582
 583         if (unlikely(lcoreid >= LTHREAD_MAX_LCORES))
 584                 return POSIX_ERRNO(EINVAL);
 585
 586         DIAG_EVENT(lt, LT_DIAG_LTHREAD_AFFINITY, lcoreid, 0);
 587
 588         dest_sched = schedcore[lcoreid];
 589
 590         if (unlikely(dest_sched == NULL))
 591                 return POSIX_ERRNO(EINVAL);
 592
 593         if (likely(dest_sched != THIS_SCHED)) {
 594                 lt->sched = dest_sched;
 595                 lt->pending_wr_queue = dest_sched->pready;
 596                 _affinitize();
 597                 return 0;
 598         }
 599         return 0;
 600 }