workqueue.c

   1 /*
   2  * Rated submission helpers
   3  *
   4  * Copyright (C) 2015 Jens Axboe <axboe@kernel.dk>
   5  *
   6  */
   7 #include <unistd.h>
   8
   9 #include "fio.h"
  10 #include "ioengine.h"
  11 #include "flist.h"
  12 #include "workqueue.h"
  13 #include "lib/getrusage.h"
  14
  15 struct submit_worker {
  16         pthread_t thread;
  17         pthread_mutex_t lock;
  18         pthread_cond_t cond;
  19         struct flist_head work_list;
  20         unsigned int flags;
  21         unsigned int index;
  22         uint64_t seq;
  23         struct workqueue *wq;
  24         struct thread_data td;
  25 };
  26
  27 enum {
  28         SW_F_IDLE       = 1 << 0,
  29         SW_F_RUNNING    = 1 << 1,
  30         SW_F_EXIT       = 1 << 2,
  31         SW_F_EXITED     = 1 << 3,
  32         SW_F_ACCOUNTED  = 1 << 4,
  33         SW_F_ERROR      = 1 << 5,
  34 };
  35
  36 static struct submit_worker *__get_submit_worker(struct workqueue *wq,
  37                                                  unsigned int start,
  38                                                  unsigned int end,
  39                                                  struct submit_worker **best)
  40 {
  41         struct submit_worker *sw = NULL;
  42
  43         while (start <= end) {
  44                 sw = &wq->workers[start];
  45                 if (sw->flags & SW_F_IDLE)
  46                         return sw;
  47                 if (!(*best) || sw->seq < (*best)->seq)
  48                         *best = sw;
  49                 start++;
  50         }
  51
  52         return NULL;
  53 }
  54
  55 static struct submit_worker *get_submit_worker(struct workqueue *wq)
  56 {
  57         unsigned int next = wq->next_free_worker;
  58         struct submit_worker *sw, *best = NULL;
  59
  60         assert(next < wq->max_workers);
  61
  62         sw = __get_submit_worker(wq, next, wq->max_workers - 1, &best);
  63         if (!sw && next)
  64                 sw = __get_submit_worker(wq, 0, next - 1, &best);
  65
  66         /*
  67          * No truly idle found, use best match
  68          */
  69         if (!sw)
  70                 sw = best;
  71
  72         if (sw->index == wq->next_free_worker) {
  73                 if (sw->index + 1 < wq->max_workers)
  74                         wq->next_free_worker = sw->index + 1;
  75                 else
  76                         wq->next_free_worker = 0;
  77         }
  78
  79         return sw;
  80 }
  81
  82 static bool all_sw_idle(struct workqueue *wq)
  83 {
  84         int i;
  85
  86         for (i = 0; i < wq->max_workers; i++) {
  87                 struct submit_worker *sw = &wq->workers[i];
  88
  89                 if (!(sw->flags & SW_F_IDLE))
  90                         return false;
  91         }
  92
  93         return true;
  94 }
  95
  96 /*
  97  * Must be serialized wrt workqueue_enqueue() by caller
  98  */
  99 void workqueue_flush(struct workqueue *wq)
 100 {
 101         wq->wake_idle = 1;
 102
 103         while (!all_sw_idle(wq)) {
 104                 pthread_mutex_lock(&wq->flush_lock);
 105                 pthread_cond_wait(&wq->flush_cond, &wq->flush_lock);
 106                 pthread_mutex_unlock(&wq->flush_lock);
 107         }
 108
 109         wq->wake_idle = 0;
 110 }
 111
 112 /*
 113  * Must be serialized by caller. Returns true for queued, false for busy.
 114  */
 115 bool workqueue_enqueue(struct workqueue *wq, struct io_u *io_u)
 116 {
 117         struct submit_worker *sw;
 118
 119         sw = get_submit_worker(wq);
 120         if (sw) {
 121                 pthread_mutex_lock(&sw->lock);
 122                 flist_add_tail(&io_u->verify_list, &sw->work_list);
 123                 sw->seq = ++wq->work_seq;
 124                 sw->flags &= ~SW_F_IDLE;
 125                 pthread_mutex_unlock(&sw->lock);
 126
 127                 pthread_cond_signal(&sw->cond);
 128                 return true;
 129         }
 130
 131         return false;
 132 }
 133
 134 static void handle_list(struct submit_worker *sw, struct flist_head *list)
 135 {
 136         struct workqueue *wq = sw->wq;
 137         struct io_u *io_u;
 138
 139         while (!flist_empty(list)) {
 140                 io_u = flist_first_entry(list, struct io_u, verify_list);
 141                 flist_del_init(&io_u->verify_list);
 142                 wq->fn(&sw->td, io_u);
 143         }
 144 }
 145
 146 static int init_submit_worker(struct submit_worker *sw)
 147 {
 148         struct thread_data *parent = sw->wq->td;
 149         struct thread_data *td = &sw->td;
 150         int fio_unused ret;
 151
 152         memcpy(&td->o, &parent->o, sizeof(td->o));
 153         memcpy(&td->ts, &parent->ts, sizeof(td->ts));
 154         td->o.uid = td->o.gid = -1U;
 155         dup_files(td, parent);
 156         td->eo = parent->eo;
 157         fio_options_mem_dupe(td);
 158
 159         if (ioengine_load(td))
 160                 goto err;
 161
 162         if (td->o.odirect)
 163                 td->io_ops->flags |= FIO_RAWIO;
 164
 165         td->pid = gettid();
 166
 167         INIT_FLIST_HEAD(&td->io_log_list);
 168         INIT_FLIST_HEAD(&td->io_hist_list);
 169         INIT_FLIST_HEAD(&td->verify_list);
 170         INIT_FLIST_HEAD(&td->trim_list);
 171         INIT_FLIST_HEAD(&td->next_rand_list);
 172         td->io_hist_tree = RB_ROOT;
 173
 174         td->o.iodepth = 1;
 175         if (td_io_init(td))
 176                 goto err_io_init;
 177
 178         fio_gettime(&td->epoch, NULL);
 179         fio_getrusage(&td->ru_start);
 180         clear_io_state(td, 1);
 181
 182         td_set_runstate(td, TD_RUNNING);
 183         td->flags |= TD_F_CHILD;
 184         td->parent = parent;
 185         return 0;
 186
 187 err_io_init:
 188         close_ioengine(td);
 189 err:
 190         return 1;
 191 }
 192
 193 #ifdef CONFIG_SFAA
 194 static void sum_val(uint64_t *dst, uint64_t *src)
 195 {
 196         if (*src) {
 197                 __sync_fetch_and_add(dst, *src);
 198                 *src = 0;
 199         }
 200 }
 201 #else
 202 static void sum_val(uint64_t *dst, uint64_t *src)
 203 {
 204         if (*src) {
 205                 *dst += *src;
 206                 *src = 0;
 207         }
 208 }
 209 #endif
 210
 211 static void pthread_double_unlock(pthread_mutex_t *lock1,
 212                                   pthread_mutex_t *lock2)
 213 {
 214 #ifndef CONFIG_SFAA
 215         pthread_mutex_unlock(lock1);
 216         pthread_mutex_unlock(lock2);
 217 #endif
 218 }
 219
 220 static void pthread_double_lock(pthread_mutex_t *lock1, pthread_mutex_t *lock2)
 221 {
 222 #ifndef CONFIG_SFAA
 223         if (lock1 < lock2) {
 224                 pthread_mutex_lock(lock1);
 225                 pthread_mutex_lock(lock2);
 226         } else {
 227                 pthread_mutex_lock(lock2);
 228                 pthread_mutex_lock(lock1);
 229         }
 230 #endif
 231 }
 232
 233 static void sum_ddir(struct thread_data *dst, struct thread_data *src,
 234                      enum fio_ddir ddir)
 235 {
 236         pthread_double_lock(&dst->io_wq.stat_lock, &src->io_wq.stat_lock);
 237
 238         sum_val(&dst->io_bytes[ddir], &src->io_bytes[ddir]);
 239         sum_val(&dst->io_blocks[ddir], &src->io_blocks[ddir]);
 240         sum_val(&dst->this_io_blocks[ddir], &src->this_io_blocks[ddir]);
 241         sum_val(&dst->this_io_bytes[ddir], &src->this_io_bytes[ddir]);
 242         sum_val(&dst->bytes_done[ddir], &src->bytes_done[ddir]);
 243
 244         pthread_double_unlock(&dst->io_wq.stat_lock, &src->io_wq.stat_lock);
 245 }
 246
 247 static void update_accounting(struct submit_worker *sw)
 248 {
 249         struct thread_data *src = &sw->td;
 250         struct thread_data *dst = sw->wq->td;
 251
 252         if (td_read(src))
 253                 sum_ddir(dst, src, DDIR_READ);
 254         if (td_write(src))
 255                 sum_ddir(dst, src, DDIR_WRITE);
 256         if (td_trim(src))
 257                 sum_ddir(dst, src, DDIR_TRIM);
 258 }
 259
 260 static void *worker_thread(void *data)
 261 {
 262         struct submit_worker *sw = data;
 263         struct workqueue *wq = sw->wq;
 264         struct thread_data *td = &sw->td;
 265         unsigned int eflags = 0, ret;
 266         FLIST_HEAD(local_list);
 267
 268         ret = init_submit_worker(sw);
 269         pthread_mutex_lock(&sw->lock);
 270         sw->flags |= SW_F_RUNNING;
 271         if (ret)
 272                 sw->flags |= SW_F_ERROR;
 273         pthread_mutex_unlock(&sw->lock);
 274
 275         pthread_mutex_lock(&wq->flush_lock);
 276         pthread_cond_signal(&wq->flush_cond);
 277         pthread_mutex_unlock(&wq->flush_lock);
 278
 279         if (sw->flags & SW_F_ERROR)
 280                 goto done;
 281
 282         while (1) {
 283                 pthread_mutex_lock(&sw->lock);
 284
 285                 if (flist_empty(&sw->work_list)) {
 286                         if (sw->flags & SW_F_EXIT) {
 287                                 pthread_mutex_unlock(&sw->lock);
 288                                 break;
 289                         }
 290
 291                         if (td->io_u_queued || td->cur_depth ||
 292                             td->io_u_in_flight) {
 293                                 int ret;
 294
 295                                 pthread_mutex_unlock(&sw->lock);
 296                                 ret = io_u_quiesce(td);
 297                                 if (ret > 0)
 298                                         td->cur_depth -= ret;
 299                                 pthread_mutex_lock(&sw->lock);
 300                         }
 301
 302                         /*
 303                          * We dropped and reaquired the lock, check
 304                          * state again.
 305                          */
 306                         if (!flist_empty(&sw->work_list))
 307                                 goto handle_work;
 308
 309                         if (sw->flags & SW_F_EXIT) {
 310                                 pthread_mutex_unlock(&sw->lock);
 311                                 break;
 312                         } else if (!(sw->flags & SW_F_IDLE)) {
 313                                 sw->flags |= SW_F_IDLE;
 314                                 wq->next_free_worker = sw->index;
 315                                 if (wq->wake_idle)
 316                                         pthread_cond_signal(&wq->flush_cond);
 317                         }
 318                         update_accounting(sw);
 319                         pthread_cond_wait(&sw->cond, &sw->lock);
 320                 } else {
 321 handle_work:
 322                         flist_splice_init(&sw->work_list, &local_list);
 323                 }
 324                 pthread_mutex_unlock(&sw->lock);
 325                 handle_list(sw, &local_list);
 326         }
 327
 328         update_accounting(sw);
 329
 330 done:
 331         pthread_mutex_lock(&sw->lock);
 332         sw->flags |= (SW_F_EXITED | eflags);
 333         pthread_mutex_unlock(&sw->lock);
 334         return NULL;
 335 }
 336
 337 static void free_worker(struct submit_worker *sw)
 338 {
 339         struct thread_data *td = &sw->td;
 340
 341         fio_options_free(td);
 342         close_and_free_files(td);
 343         if (td->io_ops)
 344                 close_ioengine(td);
 345         td_set_runstate(td, TD_EXITED);
 346
 347         pthread_cond_destroy(&sw->cond);
 348         pthread_mutex_destroy(&sw->lock);
 349 }
 350
 351 static void shutdown_worker(struct submit_worker *sw, unsigned int *sum_cnt)
 352 {
 353         struct thread_data *parent = sw->wq->td;
 354
 355         pthread_join(sw->thread, NULL);
 356         (*sum_cnt)++;
 357         sum_thread_stats(&parent->ts, &sw->td.ts, *sum_cnt == 1);
 358         free_worker(sw);
 359 }
 360
 361 void workqueue_exit(struct workqueue *wq)
 362 {
 363         unsigned int shutdown, sum_cnt = 0;
 364         struct submit_worker *sw;
 365         int i;
 366
 367         for (i = 0; i < wq->max_workers; i++) {
 368                 sw = &wq->workers[i];
 369
 370                 pthread_mutex_lock(&sw->lock);
 371                 sw->flags |= SW_F_EXIT;
 372                 pthread_cond_signal(&sw->cond);
 373                 pthread_mutex_unlock(&sw->lock);
 374         }
 375
 376         do {
 377                 shutdown = 0;
 378                 for (i = 0; i < wq->max_workers; i++) {
 379                         sw = &wq->workers[i];
 380                         if (sw->flags & SW_F_ACCOUNTED)
 381                                 continue;
 382                         pthread_mutex_lock(&sw->lock);
 383                         sw->flags |= SW_F_ACCOUNTED;
 384                         pthread_mutex_unlock(&sw->lock);
 385                         shutdown_worker(sw, &sum_cnt);
 386                         shutdown++;
 387                 }
 388         } while (shutdown && shutdown != wq->max_workers);
 389
 390         free(wq->workers);
 391         pthread_mutex_destroy(&wq->flush_lock);
 392         pthread_cond_destroy(&wq->flush_cond);
 393         pthread_mutex_destroy(&wq->stat_lock);
 394 }
 395
 396 static int start_worker(struct workqueue *wq, unsigned int index)
 397 {
 398         struct submit_worker *sw = &wq->workers[index];
 399         int ret;
 400
 401         INIT_FLIST_HEAD(&sw->work_list);
 402         pthread_cond_init(&sw->cond, NULL);
 403         pthread_mutex_init(&sw->lock, NULL);
 404         sw->wq = wq;
 405         sw->index = index;
 406
 407         ret = pthread_create(&sw->thread, NULL, worker_thread, sw);
 408         if (!ret) {
 409                 pthread_mutex_lock(&sw->lock);
 410                 sw->flags = SW_F_IDLE;
 411                 pthread_mutex_unlock(&sw->lock);
 412                 return 0;
 413         }
 414
 415         free_worker(sw);
 416         return 1;
 417 }
 418
 419 int workqueue_init(struct thread_data *td, struct workqueue *wq,
 420                    workqueue_fn *fn, unsigned max_pending)
 421 {
 422         unsigned int running;
 423         int i, error;
 424
 425         wq->max_workers = max_pending;
 426         wq->td = td;
 427         wq->fn = fn;
 428         wq->work_seq = 0;
 429         wq->next_free_worker = 0;
 430         pthread_cond_init(&wq->flush_cond, NULL);
 431         pthread_mutex_init(&wq->flush_lock, NULL);
 432         pthread_mutex_init(&wq->stat_lock, NULL);
 433
 434         wq->workers = calloc(wq->max_workers, sizeof(struct submit_worker));
 435
 436         for (i = 0; i < wq->max_workers; i++)
 437                 if (start_worker(wq, i))
 438                         break;
 439
 440         wq->max_workers = i;
 441         if (!wq->max_workers)
 442                 goto err;
 443
 444         /*
 445          * Wait for them all to be started and initialized
 446          */
 447         error = 0;
 448         do {
 449                 struct submit_worker *sw;
 450
 451                 running = 0;
 452                 pthread_mutex_lock(&wq->flush_lock);
 453                 for (i = 0; i < wq->max_workers; i++) {
 454                         sw = &wq->workers[i];
 455                         pthread_mutex_lock(&sw->lock);
 456                         if (sw->flags & SW_F_RUNNING)
 457                                 running++;
 458                         if (sw->flags & SW_F_ERROR)
 459                                 error++;
 460                         pthread_mutex_unlock(&sw->lock);
 461                 }
 462
 463                 if (error || running == wq->max_workers) {
 464                         pthread_mutex_unlock(&wq->flush_lock);
 465                         break;
 466                 }
 467
 468                 pthread_cond_wait(&wq->flush_cond, &wq->flush_lock);
 469                 pthread_mutex_unlock(&wq->flush_lock);
 470         } while (1);
 471
 472         if (!error)
 473                 return 0;
 474
 475 err:
 476         log_err("Can't create rate workqueue\n");
 477         td_verror(td, ESRCH, "workqueue_init");
 478         workqueue_exit(wq);
 479         return 1;
 480 }