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_config.h>
  80 #include <rte_prefetch.h>
  81 #include <rte_per_lcore.h>
  82 #include <rte_atomic.h>
  83 #include <rte_atomic_64.h>
  84 #include <rte_log.h>
  85 #include <rte_common.h>
  86 #include <rte_branch_prediction.h>
  87
  88 #include "lthread_api.h"
  89 #include "lthread_int.h"
  90 #include "lthread_sched.h"
  91 #include "lthread_objcache.h"
  92 #include "lthread_timer.h"
  93 #include "lthread_mutex.h"
  94 #include "lthread_cond.h"
  95 #include "lthread_tls.h"
  96 #include "lthread_diag.h"
  97
  98 /*
  99  * This file implements the lthread scheduler
 100  * The scheduler is the function lthread_run()
 101  * This must be run as the main loop of an EAL thread.
 102  *
 103  * Currently once a scheduler is created it cannot be destroyed
 104  * When a scheduler shuts down it is assumed that the application is terminating
 105  */
 106
 107 static rte_atomic16_t num_schedulers;
 108 static rte_atomic16_t active_schedulers;
 109
 110 /* one scheduler per lcore */
 111 RTE_DEFINE_PER_LCORE(struct lthread_sched *, this_sched) = NULL;
 112
 113 struct lthread_sched *schedcore[LTHREAD_MAX_LCORES];
 114
 115 diag_callback diag_cb;
 116
 117 uint64_t diag_mask;
 118
 119
 120 /* constructor */
 121 void lthread_sched_ctor(void) __attribute__ ((constructor));
 122 void lthread_sched_ctor(void)
 123 {
 124         memset(schedcore, 0, sizeof(schedcore));
 125         rte_atomic16_init(&num_schedulers);
 126         rte_atomic16_set(&num_schedulers, 1);
 127         rte_atomic16_init(&active_schedulers);
 128         rte_atomic16_set(&active_schedulers, 0);
 129         diag_cb = NULL;
 130 }
 131
 132
 133 enum sched_alloc_phase {
 134         SCHED_ALLOC_OK,
 135         SCHED_ALLOC_QNODE_POOL,
 136         SCHED_ALLOC_READY_QUEUE,
 137         SCHED_ALLOC_PREADY_QUEUE,
 138         SCHED_ALLOC_LTHREAD_CACHE,
 139         SCHED_ALLOC_STACK_CACHE,
 140         SCHED_ALLOC_PERLT_CACHE,
 141         SCHED_ALLOC_TLS_CACHE,
 142         SCHED_ALLOC_COND_CACHE,
 143         SCHED_ALLOC_MUTEX_CACHE,
 144 };
 145
 146 static int
 147 _lthread_sched_alloc_resources(struct lthread_sched *new_sched)
 148 {
 149         int alloc_status;
 150
 151         do {
 152                 /* Initialize per scheduler queue node pool */
 153                 alloc_status = SCHED_ALLOC_QNODE_POOL;
 154                 new_sched->qnode_pool =
 155                         _qnode_pool_create("qnode pool", LTHREAD_PREALLOC);
 156                 if (new_sched->qnode_pool == NULL)
 157                         break;
 158
 159                 /* Initialize per scheduler local ready queue */
 160                 alloc_status = SCHED_ALLOC_READY_QUEUE;
 161                 new_sched->ready = _lthread_queue_create("ready queue");
 162                 if (new_sched->ready == NULL)
 163                         break;
 164
 165                 /* Initialize per scheduler local peer ready queue */
 166                 alloc_status = SCHED_ALLOC_PREADY_QUEUE;
 167                 new_sched->pready = _lthread_queue_create("pready queue");
 168                 if (new_sched->pready == NULL)
 169                         break;
 170
 171                 /* Initialize per scheduler local free lthread cache */
 172                 alloc_status = SCHED_ALLOC_LTHREAD_CACHE;
 173                 new_sched->lthread_cache =
 174                         _lthread_objcache_create("lthread cache",
 175                                                 sizeof(struct lthread),
 176                                                 LTHREAD_PREALLOC);
 177                 if (new_sched->lthread_cache == NULL)
 178                         break;
 179
 180                 /* Initialize per scheduler local free stack cache */
 181                 alloc_status = SCHED_ALLOC_STACK_CACHE;
 182                 new_sched->stack_cache =
 183                         _lthread_objcache_create("stack_cache",
 184                                                 sizeof(struct lthread_stack),
 185                                                 LTHREAD_PREALLOC);
 186                 if (new_sched->stack_cache == NULL)
 187                         break;
 188
 189                 /* Initialize per scheduler local free per lthread data cache */
 190                 alloc_status = SCHED_ALLOC_PERLT_CACHE;
 191                 new_sched->per_lthread_cache =
 192                         _lthread_objcache_create("per_lt cache",
 193                                                 RTE_PER_LTHREAD_SECTION_SIZE,
 194                                                 LTHREAD_PREALLOC);
 195                 if (new_sched->per_lthread_cache == NULL)
 196                         break;
 197
 198                 /* Initialize per scheduler local free tls cache */
 199                 alloc_status = SCHED_ALLOC_TLS_CACHE;
 200                 new_sched->tls_cache =
 201                         _lthread_objcache_create("TLS cache",
 202                                                 sizeof(struct lthread_tls),
 203                                                 LTHREAD_PREALLOC);
 204                 if (new_sched->tls_cache == NULL)
 205                         break;
 206
 207                 /* Initialize per scheduler local free cond var cache */
 208                 alloc_status = SCHED_ALLOC_COND_CACHE;
 209                 new_sched->cond_cache =
 210                         _lthread_objcache_create("cond cache",
 211                                                 sizeof(struct lthread_cond),
 212                                                 LTHREAD_PREALLOC);
 213                 if (new_sched->cond_cache == NULL)
 214                         break;
 215
 216                 /* Initialize per scheduler local free mutex cache */
 217                 alloc_status = SCHED_ALLOC_MUTEX_CACHE;
 218                 new_sched->mutex_cache =
 219                         _lthread_objcache_create("mutex cache",
 220                                                 sizeof(struct lthread_mutex),
 221                                                 LTHREAD_PREALLOC);
 222                 if (new_sched->mutex_cache == NULL)
 223                         break;
 224
 225                 alloc_status = SCHED_ALLOC_OK;
 226         } while (0);
 227
 228         /* roll back on any failure */
 229         switch (alloc_status) {
 230         case SCHED_ALLOC_MUTEX_CACHE:
 231                 _lthread_objcache_destroy(new_sched->cond_cache);
 232                 /* fall through */
 233         case SCHED_ALLOC_COND_CACHE:
 234                 _lthread_objcache_destroy(new_sched->tls_cache);
 235                 /* fall through */
 236         case SCHED_ALLOC_TLS_CACHE:
 237                 _lthread_objcache_destroy(new_sched->per_lthread_cache);
 238                 /* fall through */
 239         case SCHED_ALLOC_PERLT_CACHE:
 240                 _lthread_objcache_destroy(new_sched->stack_cache);
 241                 /* fall through */
 242         case SCHED_ALLOC_STACK_CACHE:
 243                 _lthread_objcache_destroy(new_sched->lthread_cache);
 244                 /* fall through */
 245         case SCHED_ALLOC_LTHREAD_CACHE:
 246                 _lthread_queue_destroy(new_sched->pready);
 247                 /* fall through */
 248         case SCHED_ALLOC_PREADY_QUEUE:
 249                 _lthread_queue_destroy(new_sched->ready);
 250                 /* fall through */
 251         case SCHED_ALLOC_READY_QUEUE:
 252                 _qnode_pool_destroy(new_sched->qnode_pool);
 253                 /* fall through */
 254         case SCHED_ALLOC_QNODE_POOL:
 255                 /* fall through */
 256         case SCHED_ALLOC_OK:
 257                 break;
 258         }
 259         return alloc_status;
 260 }
 261
 262
 263 /*
 264  * Create a scheduler on the current lcore
 265  */
 266 struct lthread_sched *_lthread_sched_create(size_t stack_size)
 267 {
 268         int status;
 269         struct lthread_sched *new_sched;
 270         unsigned lcoreid = rte_lcore_id();
 271
 272         LTHREAD_ASSERT(stack_size <= LTHREAD_MAX_STACK_SIZE);
 273
 274         if (stack_size == 0)
 275                 stack_size = LTHREAD_MAX_STACK_SIZE;
 276
 277         new_sched =
 278              rte_calloc_socket(NULL, 1, sizeof(struct lthread_sched),
 279                                 RTE_CACHE_LINE_SIZE,
 280                                 rte_socket_id());
 281         if (new_sched == NULL) {
 282                 RTE_LOG(CRIT, LTHREAD,
 283                         "Failed to allocate memory for scheduler\n");
 284                 return NULL;
 285         }
 286
 287         _lthread_key_pool_init();
 288
 289         new_sched->stack_size = stack_size;
 290         new_sched->birth = rte_rdtsc();
 291         THIS_SCHED = new_sched;
 292
 293         status = _lthread_sched_alloc_resources(new_sched);
 294         if (status != SCHED_ALLOC_OK) {
 295                 RTE_LOG(CRIT, LTHREAD,
 296                         "Failed to allocate resources for scheduler code = %d\n",
 297                         status);
 298                 rte_free(new_sched);
 299                 return NULL;
 300         }
 301
 302         bzero(&new_sched->ctx, sizeof(struct ctx));
 303
 304         new_sched->lcore_id = lcoreid;
 305
 306         schedcore[lcoreid] = new_sched;
 307
 308         new_sched->run_flag = 1;
 309
 310         DIAG_EVENT(new_sched, LT_DIAG_SCHED_CREATE, rte_lcore_id(), 0);
 311
 312         rte_wmb();
 313         return new_sched;
 314 }
 315
 316 /*
 317  * Set the number of schedulers in the system
 318  */
 319 int lthread_num_schedulers_set(int num)
 320 {
 321         rte_atomic16_set(&num_schedulers, num);
 322         return (int)rte_atomic16_read(&num_schedulers);
 323 }
 324
 325 /*
 326  * Return the number of schedulers active
 327  */
 328 int lthread_active_schedulers(void)
 329 {
 330         return (int)rte_atomic16_read(&active_schedulers);
 331 }
 332
 333
 334 /**
 335  * shutdown the scheduler running on the specified lcore
 336  */
 337 void lthread_scheduler_shutdown(unsigned lcoreid)
 338 {
 339         uint64_t coreid = (uint64_t) lcoreid;
 340
 341         if (coreid < LTHREAD_MAX_LCORES) {
 342                 if (schedcore[coreid] != NULL)
 343                         schedcore[coreid]->run_flag = 0;
 344         }
 345 }
 346
 347 /**
 348  * shutdown all schedulers
 349  */
 350 void lthread_scheduler_shutdown_all(void)
 351 {
 352         uint64_t i;
 353
 354         /*
 355          * give time for all schedulers to have started
 356          * Note we use sched_yield() rather than pthread_yield() to allow
 357          * for the possibility of a pthread wrapper on lthread_yield(),
 358          * something that is not possible unless the scheduler is running.
 359          */
 360         while (rte_atomic16_read(&active_schedulers) <
 361                rte_atomic16_read(&num_schedulers))
 362                 sched_yield();
 363
 364         for (i = 0; i < LTHREAD_MAX_LCORES; i++) {
 365                 if (schedcore[i] != NULL)
 366                         schedcore[i]->run_flag = 0;
 367         }
 368 }
 369
 370 /*
 371  * Resume a suspended lthread
 372  */
 373 static inline void
 374 _lthread_resume(struct lthread *lt) __attribute__ ((always_inline));
 375 static inline void _lthread_resume(struct lthread *lt)
 376 {
 377         struct lthread_sched *sched = THIS_SCHED;
 378         struct lthread_stack *s;
 379         uint64_t state = lt->state;
 380 #if LTHREAD_DIAG
 381         int init = 0;
 382 #endif
 383
 384         sched->current_lthread = lt;
 385
 386         if (state & (BIT(ST_LT_CANCELLED) | BIT(ST_LT_EXITED))) {
 387                 /* if detached we can free the thread now */
 388                 if (state & BIT(ST_LT_DETACH)) {
 389                         _lthread_free(lt);
 390                         sched->current_lthread = NULL;
 391                         return;
 392                 }
 393         }
 394
 395         if (state & BIT(ST_LT_INIT)) {
 396                 /* first time this thread has been run */
 397                 /* assign thread to this scheduler */
 398                 lt->sched = THIS_SCHED;
 399
 400                 /* allocate stack */
 401                 s = _stack_alloc();
 402
 403                 lt->stack_container = s;
 404                 _lthread_set_stack(lt, s->stack, s->stack_size);
 405
 406                 /* allocate memory for TLS used by this thread */
 407                 _lthread_tls_alloc(lt);
 408
 409                 lt->state = BIT(ST_LT_READY);
 410 #if LTHREAD_DIAG
 411                 init = 1;
 412 #endif
 413         }
 414
 415         DIAG_EVENT(lt, LT_DIAG_LTHREAD_RESUMED, init, lt);
 416
 417         /* switch to the new thread */
 418         ctx_switch(&lt->ctx, &sched->ctx);
 419
 420         /* If posting to a queue that could be read by another lcore
 421          * we defer the queue write till now to ensure the context has been
 422          * saved before the other core tries to resume it
 423          * This applies to blocking on mutex, cond, and to set_affinity
 424          */
 425         if (lt->pending_wr_queue != NULL) {
 426                 struct lthread_queue *dest = lt->pending_wr_queue;
 427
 428                 lt->pending_wr_queue = NULL;
 429
 430                 /* queue the current thread to the specified queue */
 431                 _lthread_queue_insert_mp(dest, lt);
 432         }
 433
 434         sched->current_lthread = NULL;
 435 }
 436
 437 /*
 438  * Handle sleep timer expiry
 439 */
 440 void
 441 _sched_timer_cb(struct rte_timer *tim, void *arg)
 442 {
 443         struct lthread *lt = (struct lthread *) arg;
 444         uint64_t state = lt->state;
 445
 446         DIAG_EVENT(lt, LT_DIAG_LTHREAD_TMR_EXPIRED, &lt->tim, 0);
 447
 448         rte_timer_stop(tim);
 449
 450         if (lt->state & BIT(ST_LT_CANCELLED))
 451                 (THIS_SCHED)->nb_blocked_threads--;
 452
 453         lt->state = state | BIT(ST_LT_EXPIRED);
 454         _lthread_resume(lt);
 455         lt->state = state & CLEARBIT(ST_LT_EXPIRED);
 456 }
 457
 458
 459
 460 /*
 461  * Returns 0 if there is a pending job in scheduler or 1 if done and can exit.
 462  */
 463 static inline int _lthread_sched_isdone(struct lthread_sched *sched)
 464 {
 465         return ((sched->run_flag == 0) &&
 466                         (_lthread_queue_empty(sched->ready)) &&
 467                         (_lthread_queue_empty(sched->pready)) &&
 468                         (sched->nb_blocked_threads == 0));
 469 }
 470
 471 /*
 472  * Wait for all schedulers to start
 473  */
 474 static inline void _lthread_schedulers_sync_start(void)
 475 {
 476         rte_atomic16_inc(&active_schedulers);
 477
 478         /* wait for lthread schedulers
 479          * Note we use sched_yield() rather than pthread_yield() to allow
 480          * for the possibility of a pthread wrapper on lthread_yield(),
 481          * something that is not possible unless the scheduler is running.
 482          */
 483         while (rte_atomic16_read(&active_schedulers) <
 484                rte_atomic16_read(&num_schedulers))
 485                 sched_yield();
 486
 487 }
 488
 489 /*
 490  * Wait for all schedulers to stop
 491  */
 492 static inline void _lthread_schedulers_sync_stop(void)
 493 {
 494         rte_atomic16_dec(&active_schedulers);
 495         rte_atomic16_dec(&num_schedulers);
 496
 497         /* wait for schedulers
 498          * Note we use sched_yield() rather than pthread_yield() to allow
 499          * for the possibility of a pthread wrapper on lthread_yield(),
 500          * something that is not possible unless the scheduler is running.
 501          */
 502         while (rte_atomic16_read(&active_schedulers) > 0)
 503                 sched_yield();
 504
 505 }
 506
 507
 508 /*
 509  * Run the lthread scheduler
 510  * This loop is the heart of the system
 511  */
 512 void lthread_run(void)
 513 {
 514
 515         struct lthread_sched *sched = THIS_SCHED;
 516         struct lthread *lt = NULL;
 517
 518         RTE_LOG(INFO, LTHREAD,
 519                 "starting scheduler %p on lcore %u phys core %u\n",
 520                 sched, rte_lcore_id(),
 521                 rte_lcore_index(rte_lcore_id()));
 522
 523         /* if more than one, wait for all schedulers to start */
 524         _lthread_schedulers_sync_start();
 525
 526
 527         /*
 528          * This is the main scheduling loop
 529          * So long as there are tasks in existence we run this loop.
 530          * We check for:-
 531          *   expired timers,
 532          *   the local ready queue,
 533          *   and the peer ready queue,
 534          *
 535          * and resume lthreads ad infinitum.
 536          */
 537         while (!_lthread_sched_isdone(sched)) {
 538
 539                 rte_timer_manage();
 540
 541                 lt = _lthread_queue_poll(sched->ready);
 542                 if (lt != NULL)
 543                         _lthread_resume(lt);
 544                 lt = _lthread_queue_poll(sched->pready);
 545                 if (lt != NULL)
 546                         _lthread_resume(lt);
 547         }
 548
 549
 550         /* if more than one wait for all schedulers to stop */
 551         _lthread_schedulers_sync_stop();
 552
 553         (THIS_SCHED) = NULL;
 554
 555         RTE_LOG(INFO, LTHREAD,
 556                 "stopping scheduler %p on lcore %u phys core %u\n",
 557                 sched, rte_lcore_id(),
 558                 rte_lcore_index(rte_lcore_id()));
 559         fflush(stdout);
 560 }
 561
 562 /*
 563  * Return the scheduler for this lcore
 564  *
 565  */
 566 struct lthread_sched *_lthread_sched_get(int lcore_id)
 567 {
 568         if (lcore_id > LTHREAD_MAX_LCORES)
 569                 return NULL;
 570         return schedcore[lcore_id];
 571 }
 572
 573 /*
 574  * migrate the current thread to another scheduler running
 575  * on the specified lcore.
 576  */
 577 int lthread_set_affinity(unsigned lcoreid)
 578 {
 579         struct lthread *lt = THIS_LTHREAD;
 580         struct lthread_sched *dest_sched;
 581
 582         if (unlikely(lcoreid > LTHREAD_MAX_LCORES))
 583                 return POSIX_ERRNO(EINVAL);
 584
 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 }