1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or https://opensource.org/licenses/CDDL-1.0. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* 27 * Copyright (c) 2012, 2018 by Delphix. All rights reserved. 28 */ 29 30 #include <sys/zfs_context.h> 31 #include <sys/vdev_impl.h> 32 #include <sys/spa_impl.h> 33 #include <sys/zio.h> 34 #include <sys/avl.h> 35 #include <sys/dsl_pool.h> 36 #include <sys/metaslab_impl.h> 37 #include <sys/spa.h> 38 #include <sys/abd.h> 39 40 /* 41 * ZFS I/O Scheduler 42 * --------------- 43 * 44 * ZFS issues I/O operations to leaf vdevs to satisfy and complete zios. The 45 * I/O scheduler determines when and in what order those operations are 46 * issued. The I/O scheduler divides operations into five I/O classes 47 * prioritized in the following order: sync read, sync write, async read, 48 * async write, and scrub/resilver. Each queue defines the minimum and 49 * maximum number of concurrent operations that may be issued to the device. 50 * In addition, the device has an aggregate maximum. Note that the sum of the 51 * per-queue minimums must not exceed the aggregate maximum. If the 52 * sum of the per-queue maximums exceeds the aggregate maximum, then the 53 * number of active i/os may reach zfs_vdev_max_active, in which case no 54 * further i/os will be issued regardless of whether all per-queue 55 * minimums have been met. 56 * 57 * For many physical devices, throughput increases with the number of 58 * concurrent operations, but latency typically suffers. Further, physical 59 * devices typically have a limit at which more concurrent operations have no 60 * effect on throughput or can actually cause it to decrease. 61 * 62 * The scheduler selects the next operation to issue by first looking for an 63 * I/O class whose minimum has not been satisfied. Once all are satisfied and 64 * the aggregate maximum has not been hit, the scheduler looks for classes 65 * whose maximum has not been satisfied. Iteration through the I/O classes is 66 * done in the order specified above. No further operations are issued if the 67 * aggregate maximum number of concurrent operations has been hit or if there 68 * are no operations queued for an I/O class that has not hit its maximum. 69 * Every time an i/o is queued or an operation completes, the I/O scheduler 70 * looks for new operations to issue. 71 * 72 * All I/O classes have a fixed maximum number of outstanding operations 73 * except for the async write class. Asynchronous writes represent the data 74 * that is committed to stable storage during the syncing stage for 75 * transaction groups (see txg.c). Transaction groups enter the syncing state 76 * periodically so the number of queued async writes will quickly burst up and 77 * then bleed down to zero. Rather than servicing them as quickly as possible, 78 * the I/O scheduler changes the maximum number of active async write i/os 79 * according to the amount of dirty data in the pool (see dsl_pool.c). Since 80 * both throughput and latency typically increase with the number of 81 * concurrent operations issued to physical devices, reducing the burstiness 82 * in the number of concurrent operations also stabilizes the response time of 83 * operations from other -- and in particular synchronous -- queues. In broad 84 * strokes, the I/O scheduler will issue more concurrent operations from the 85 * async write queue as there's more dirty data in the pool. 86 * 87 * Async Writes 88 * 89 * The number of concurrent operations issued for the async write I/O class 90 * follows a piece-wise linear function defined by a few adjustable points. 91 * 92 * | o---------| <-- zfs_vdev_async_write_max_active 93 * ^ | /^ | 94 * | | / | | 95 * active | / | | 96 * I/O | / | | 97 * count | / | | 98 * | / | | 99 * |------------o | | <-- zfs_vdev_async_write_min_active 100 * 0|____________^______|_________| 101 * 0% | | 100% of zfs_dirty_data_max 102 * | | 103 * | `-- zfs_vdev_async_write_active_max_dirty_percent 104 * `--------- zfs_vdev_async_write_active_min_dirty_percent 105 * 106 * Until the amount of dirty data exceeds a minimum percentage of the dirty 107 * data allowed in the pool, the I/O scheduler will limit the number of 108 * concurrent operations to the minimum. As that threshold is crossed, the 109 * number of concurrent operations issued increases linearly to the maximum at 110 * the specified maximum percentage of the dirty data allowed in the pool. 111 * 112 * Ideally, the amount of dirty data on a busy pool will stay in the sloped 113 * part of the function between zfs_vdev_async_write_active_min_dirty_percent 114 * and zfs_vdev_async_write_active_max_dirty_percent. If it exceeds the 115 * maximum percentage, this indicates that the rate of incoming data is 116 * greater than the rate that the backend storage can handle. In this case, we 117 * must further throttle incoming writes (see dmu_tx_delay() for details). 118 */ 119 120 /* 121 * The maximum number of i/os active to each device. Ideally, this will be >= 122 * the sum of each queue's max_active. 123 */ 124 uint_t zfs_vdev_max_active = 1000; 125 126 /* 127 * Per-queue limits on the number of i/os active to each device. If the 128 * number of active i/os is < zfs_vdev_max_active, then the min_active comes 129 * into play. We will send min_active from each queue round-robin, and then 130 * send from queues in the order defined by zio_priority_t up to max_active. 131 * Some queues have additional mechanisms to limit number of active I/Os in 132 * addition to min_active and max_active, see below. 133 * 134 * In general, smaller max_active's will lead to lower latency of synchronous 135 * operations. Larger max_active's may lead to higher overall throughput, 136 * depending on underlying storage. 137 * 138 * The ratio of the queues' max_actives determines the balance of performance 139 * between reads, writes, and scrubs. E.g., increasing 140 * zfs_vdev_scrub_max_active will cause the scrub or resilver to complete 141 * more quickly, but reads and writes to have higher latency and lower 142 * throughput. 143 */ 144 static uint_t zfs_vdev_sync_read_min_active = 10; 145 static uint_t zfs_vdev_sync_read_max_active = 10; 146 static uint_t zfs_vdev_sync_write_min_active = 10; 147 static uint_t zfs_vdev_sync_write_max_active = 10; 148 static uint_t zfs_vdev_async_read_min_active = 1; 149 /* */ uint_t zfs_vdev_async_read_max_active = 3; 150 static uint_t zfs_vdev_async_write_min_active = 2; 151 /* */ uint_t zfs_vdev_async_write_max_active = 10; 152 static uint_t zfs_vdev_scrub_min_active = 1; 153 static uint_t zfs_vdev_scrub_max_active = 3; 154 static uint_t zfs_vdev_removal_min_active = 1; 155 static uint_t zfs_vdev_removal_max_active = 2; 156 static uint_t zfs_vdev_initializing_min_active = 1; 157 static uint_t zfs_vdev_initializing_max_active = 1; 158 static uint_t zfs_vdev_trim_min_active = 1; 159 static uint_t zfs_vdev_trim_max_active = 2; 160 static uint_t zfs_vdev_rebuild_min_active = 1; 161 static uint_t zfs_vdev_rebuild_max_active = 3; 162 163 /* 164 * When the pool has less than zfs_vdev_async_write_active_min_dirty_percent 165 * dirty data, use zfs_vdev_async_write_min_active. When it has more than 166 * zfs_vdev_async_write_active_max_dirty_percent, use 167 * zfs_vdev_async_write_max_active. The value is linearly interpolated 168 * between min and max. 169 */ 170 uint_t zfs_vdev_async_write_active_min_dirty_percent = 30; 171 uint_t zfs_vdev_async_write_active_max_dirty_percent = 60; 172 173 /* 174 * For non-interactive I/O (scrub, resilver, removal, initialize and rebuild), 175 * the number of concurrently-active I/O's is limited to *_min_active, unless 176 * the vdev is "idle". When there are no interactive I/Os active (sync or 177 * async), and zfs_vdev_nia_delay I/Os have completed since the last 178 * interactive I/O, then the vdev is considered to be "idle", and the number 179 * of concurrently-active non-interactive I/O's is increased to *_max_active. 180 */ 181 static uint_t zfs_vdev_nia_delay = 5; 182 183 /* 184 * Some HDDs tend to prioritize sequential I/O so high that concurrent 185 * random I/O latency reaches several seconds. On some HDDs it happens 186 * even if sequential I/Os are submitted one at a time, and so setting 187 * *_max_active to 1 does not help. To prevent non-interactive I/Os, like 188 * scrub, from monopolizing the device no more than zfs_vdev_nia_credit 189 * I/Os can be sent while there are outstanding incomplete interactive 190 * I/Os. This enforced wait ensures the HDD services the interactive I/O 191 * within a reasonable amount of time. 192 */ 193 static uint_t zfs_vdev_nia_credit = 5; 194 195 /* 196 * To reduce IOPs, we aggregate small adjacent I/Os into one large I/O. 197 * For read I/Os, we also aggregate across small adjacency gaps; for writes 198 * we include spans of optional I/Os to aid aggregation at the disk even when 199 * they aren't able to help us aggregate at this level. 200 */ 201 static uint_t zfs_vdev_aggregation_limit = 1 << 20; 202 static uint_t zfs_vdev_aggregation_limit_non_rotating = SPA_OLD_MAXBLOCKSIZE; 203 static uint_t zfs_vdev_read_gap_limit = 32 << 10; 204 static uint_t zfs_vdev_write_gap_limit = 4 << 10; 205 206 /* 207 * Define the queue depth percentage for each top-level. This percentage is 208 * used in conjunction with zfs_vdev_async_max_active to determine how many 209 * allocations a specific top-level vdev should handle. Once the queue depth 210 * reaches zfs_vdev_queue_depth_pct * zfs_vdev_async_write_max_active / 100 211 * then allocator will stop allocating blocks on that top-level device. 212 * The default kernel setting is 1000% which will yield 100 allocations per 213 * device. For userland testing, the default setting is 300% which equates 214 * to 30 allocations per device. 215 */ 216 #ifdef _KERNEL 217 uint_t zfs_vdev_queue_depth_pct = 1000; 218 #else 219 uint_t zfs_vdev_queue_depth_pct = 300; 220 #endif 221 222 /* 223 * When performing allocations for a given metaslab, we want to make sure that 224 * there are enough IOs to aggregate together to improve throughput. We want to 225 * ensure that there are at least 128k worth of IOs that can be aggregated, and 226 * we assume that the average allocation size is 4k, so we need the queue depth 227 * to be 32 per allocator to get good aggregation of sequential writes. 228 */ 229 uint_t zfs_vdev_def_queue_depth = 32; 230 231 static int 232 vdev_queue_offset_compare(const void *x1, const void *x2) 233 { 234 const zio_t *z1 = (const zio_t *)x1; 235 const zio_t *z2 = (const zio_t *)x2; 236 237 int cmp = TREE_CMP(z1->io_offset, z2->io_offset); 238 239 if (likely(cmp)) 240 return (cmp); 241 242 return (TREE_PCMP(z1, z2)); 243 } 244 245 #define VDQ_T_SHIFT 29 246 247 static int 248 vdev_queue_to_compare(const void *x1, const void *x2) 249 { 250 const zio_t *z1 = (const zio_t *)x1; 251 const zio_t *z2 = (const zio_t *)x2; 252 253 int tcmp = TREE_CMP(z1->io_timestamp >> VDQ_T_SHIFT, 254 z2->io_timestamp >> VDQ_T_SHIFT); 255 int ocmp = TREE_CMP(z1->io_offset, z2->io_offset); 256 int cmp = tcmp ? tcmp : ocmp; 257 258 if (likely(cmp | (z1->io_queue_state == ZIO_QS_NONE))) 259 return (cmp); 260 261 return (TREE_PCMP(z1, z2)); 262 } 263 264 static inline boolean_t 265 vdev_queue_class_fifo(zio_priority_t p) 266 { 267 return (p == ZIO_PRIORITY_SYNC_READ || p == ZIO_PRIORITY_SYNC_WRITE || 268 p == ZIO_PRIORITY_TRIM); 269 } 270 271 static void 272 vdev_queue_class_add(vdev_queue_t *vq, zio_t *zio) 273 { 274 zio_priority_t p = zio->io_priority; 275 vq->vq_cqueued |= 1U << p; 276 if (vdev_queue_class_fifo(p)) { 277 list_insert_tail(&vq->vq_class[p].vqc_list, zio); 278 vq->vq_class[p].vqc_list_numnodes++; 279 } 280 else 281 avl_add(&vq->vq_class[p].vqc_tree, zio); 282 } 283 284 static void 285 vdev_queue_class_remove(vdev_queue_t *vq, zio_t *zio) 286 { 287 zio_priority_t p = zio->io_priority; 288 uint32_t empty; 289 if (vdev_queue_class_fifo(p)) { 290 list_t *list = &vq->vq_class[p].vqc_list; 291 list_remove(list, zio); 292 empty = list_is_empty(list); 293 vq->vq_class[p].vqc_list_numnodes--; 294 } else { 295 avl_tree_t *tree = &vq->vq_class[p].vqc_tree; 296 avl_remove(tree, zio); 297 empty = avl_is_empty(tree); 298 } 299 vq->vq_cqueued &= ~(empty << p); 300 } 301 302 static uint_t 303 vdev_queue_class_min_active(vdev_queue_t *vq, zio_priority_t p) 304 { 305 switch (p) { 306 case ZIO_PRIORITY_SYNC_READ: 307 return (zfs_vdev_sync_read_min_active); 308 case ZIO_PRIORITY_SYNC_WRITE: 309 return (zfs_vdev_sync_write_min_active); 310 case ZIO_PRIORITY_ASYNC_READ: 311 return (zfs_vdev_async_read_min_active); 312 case ZIO_PRIORITY_ASYNC_WRITE: 313 return (zfs_vdev_async_write_min_active); 314 case ZIO_PRIORITY_SCRUB: 315 return (vq->vq_ia_active == 0 ? zfs_vdev_scrub_min_active : 316 MIN(vq->vq_nia_credit, zfs_vdev_scrub_min_active)); 317 case ZIO_PRIORITY_REMOVAL: 318 return (vq->vq_ia_active == 0 ? zfs_vdev_removal_min_active : 319 MIN(vq->vq_nia_credit, zfs_vdev_removal_min_active)); 320 case ZIO_PRIORITY_INITIALIZING: 321 return (vq->vq_ia_active == 0 ?zfs_vdev_initializing_min_active: 322 MIN(vq->vq_nia_credit, zfs_vdev_initializing_min_active)); 323 case ZIO_PRIORITY_TRIM: 324 return (zfs_vdev_trim_min_active); 325 case ZIO_PRIORITY_REBUILD: 326 return (vq->vq_ia_active == 0 ? zfs_vdev_rebuild_min_active : 327 MIN(vq->vq_nia_credit, zfs_vdev_rebuild_min_active)); 328 default: 329 panic("invalid priority %u", p); 330 return (0); 331 } 332 } 333 334 static uint_t 335 vdev_queue_max_async_writes(spa_t *spa) 336 { 337 uint_t writes; 338 uint64_t dirty = 0; 339 dsl_pool_t *dp = spa_get_dsl(spa); 340 uint64_t min_bytes = zfs_dirty_data_max * 341 zfs_vdev_async_write_active_min_dirty_percent / 100; 342 uint64_t max_bytes = zfs_dirty_data_max * 343 zfs_vdev_async_write_active_max_dirty_percent / 100; 344 345 /* 346 * Async writes may occur before the assignment of the spa's 347 * dsl_pool_t if a self-healing zio is issued prior to the 348 * completion of dmu_objset_open_impl(). 349 */ 350 if (dp == NULL) 351 return (zfs_vdev_async_write_max_active); 352 353 /* 354 * Sync tasks correspond to interactive user actions. To reduce the 355 * execution time of those actions we push data out as fast as possible. 356 */ 357 dirty = dp->dp_dirty_total; 358 if (dirty > max_bytes || spa_has_pending_synctask(spa)) 359 return (zfs_vdev_async_write_max_active); 360 361 if (dirty < min_bytes) 362 return (zfs_vdev_async_write_min_active); 363 364 /* 365 * linear interpolation: 366 * slope = (max_writes - min_writes) / (max_bytes - min_bytes) 367 * move right by min_bytes 368 * move up by min_writes 369 */ 370 writes = (dirty - min_bytes) * 371 (zfs_vdev_async_write_max_active - 372 zfs_vdev_async_write_min_active) / 373 (max_bytes - min_bytes) + 374 zfs_vdev_async_write_min_active; 375 ASSERT3U(writes, >=, zfs_vdev_async_write_min_active); 376 ASSERT3U(writes, <=, zfs_vdev_async_write_max_active); 377 return (writes); 378 } 379 380 static uint_t 381 vdev_queue_class_max_active(vdev_queue_t *vq, zio_priority_t p) 382 { 383 switch (p) { 384 case ZIO_PRIORITY_SYNC_READ: 385 return (zfs_vdev_sync_read_max_active); 386 case ZIO_PRIORITY_SYNC_WRITE: 387 return (zfs_vdev_sync_write_max_active); 388 case ZIO_PRIORITY_ASYNC_READ: 389 return (zfs_vdev_async_read_max_active); 390 case ZIO_PRIORITY_ASYNC_WRITE: 391 return (vdev_queue_max_async_writes(vq->vq_vdev->vdev_spa)); 392 case ZIO_PRIORITY_SCRUB: 393 if (vq->vq_ia_active > 0) { 394 return (MIN(vq->vq_nia_credit, 395 zfs_vdev_scrub_min_active)); 396 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 397 return (MAX(1, zfs_vdev_scrub_min_active)); 398 return (zfs_vdev_scrub_max_active); 399 case ZIO_PRIORITY_REMOVAL: 400 if (vq->vq_ia_active > 0) { 401 return (MIN(vq->vq_nia_credit, 402 zfs_vdev_removal_min_active)); 403 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 404 return (MAX(1, zfs_vdev_removal_min_active)); 405 return (zfs_vdev_removal_max_active); 406 case ZIO_PRIORITY_INITIALIZING: 407 if (vq->vq_ia_active > 0) { 408 return (MIN(vq->vq_nia_credit, 409 zfs_vdev_initializing_min_active)); 410 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 411 return (MAX(1, zfs_vdev_initializing_min_active)); 412 return (zfs_vdev_initializing_max_active); 413 case ZIO_PRIORITY_TRIM: 414 return (zfs_vdev_trim_max_active); 415 case ZIO_PRIORITY_REBUILD: 416 if (vq->vq_ia_active > 0) { 417 return (MIN(vq->vq_nia_credit, 418 zfs_vdev_rebuild_min_active)); 419 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 420 return (MAX(1, zfs_vdev_rebuild_min_active)); 421 return (zfs_vdev_rebuild_max_active); 422 default: 423 panic("invalid priority %u", p); 424 return (0); 425 } 426 } 427 428 /* 429 * Return the i/o class to issue from, or ZIO_PRIORITY_NUM_QUEUEABLE if 430 * there is no eligible class. 431 */ 432 static zio_priority_t 433 vdev_queue_class_to_issue(vdev_queue_t *vq) 434 { 435 uint32_t cq = vq->vq_cqueued; 436 zio_priority_t p, p1; 437 438 if (cq == 0 || vq->vq_active >= zfs_vdev_max_active) 439 return (ZIO_PRIORITY_NUM_QUEUEABLE); 440 441 /* 442 * Find a queue that has not reached its minimum # outstanding i/os. 443 * Do round-robin to reduce starvation due to zfs_vdev_max_active 444 * and vq_nia_credit limits. 445 */ 446 p1 = vq->vq_last_prio + 1; 447 if (p1 >= ZIO_PRIORITY_NUM_QUEUEABLE) 448 p1 = 0; 449 for (p = p1; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 450 if ((cq & (1U << p)) != 0 && vq->vq_cactive[p] < 451 vdev_queue_class_min_active(vq, p)) 452 goto found; 453 } 454 for (p = 0; p < p1; p++) { 455 if ((cq & (1U << p)) != 0 && vq->vq_cactive[p] < 456 vdev_queue_class_min_active(vq, p)) 457 goto found; 458 } 459 460 /* 461 * If we haven't found a queue, look for one that hasn't reached its 462 * maximum # outstanding i/os. 463 */ 464 for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 465 if ((cq & (1U << p)) != 0 && vq->vq_cactive[p] < 466 vdev_queue_class_max_active(vq, p)) 467 break; 468 } 469 470 found: 471 vq->vq_last_prio = p; 472 return (p); 473 } 474 475 void 476 vdev_queue_init(vdev_t *vd) 477 { 478 vdev_queue_t *vq = &vd->vdev_queue; 479 zio_priority_t p; 480 481 vq->vq_vdev = vd; 482 483 for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 484 if (vdev_queue_class_fifo(p)) { 485 list_create(&vq->vq_class[p].vqc_list, 486 sizeof (zio_t), 487 offsetof(struct zio, io_queue_node.l)); 488 } else { 489 avl_create(&vq->vq_class[p].vqc_tree, 490 vdev_queue_to_compare, sizeof (zio_t), 491 offsetof(struct zio, io_queue_node.a)); 492 } 493 } 494 avl_create(&vq->vq_read_offset_tree, 495 vdev_queue_offset_compare, sizeof (zio_t), 496 offsetof(struct zio, io_offset_node)); 497 avl_create(&vq->vq_write_offset_tree, 498 vdev_queue_offset_compare, sizeof (zio_t), 499 offsetof(struct zio, io_offset_node)); 500 501 vq->vq_last_offset = 0; 502 list_create(&vq->vq_active_list, sizeof (struct zio), 503 offsetof(struct zio, io_queue_node.l)); 504 mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL); 505 } 506 507 void 508 vdev_queue_fini(vdev_t *vd) 509 { 510 vdev_queue_t *vq = &vd->vdev_queue; 511 512 for (zio_priority_t p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 513 if (vdev_queue_class_fifo(p)) 514 list_destroy(&vq->vq_class[p].vqc_list); 515 else 516 avl_destroy(&vq->vq_class[p].vqc_tree); 517 } 518 avl_destroy(&vq->vq_read_offset_tree); 519 avl_destroy(&vq->vq_write_offset_tree); 520 521 list_destroy(&vq->vq_active_list); 522 mutex_destroy(&vq->vq_lock); 523 } 524 525 static void 526 vdev_queue_io_add(vdev_queue_t *vq, zio_t *zio) 527 { 528 zio->io_queue_state = ZIO_QS_QUEUED; 529 vdev_queue_class_add(vq, zio); 530 if (zio->io_type == ZIO_TYPE_READ) 531 avl_add(&vq->vq_read_offset_tree, zio); 532 else if (zio->io_type == ZIO_TYPE_WRITE) 533 avl_add(&vq->vq_write_offset_tree, zio); 534 } 535 536 static void 537 vdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio) 538 { 539 vdev_queue_class_remove(vq, zio); 540 if (zio->io_type == ZIO_TYPE_READ) 541 avl_remove(&vq->vq_read_offset_tree, zio); 542 else if (zio->io_type == ZIO_TYPE_WRITE) 543 avl_remove(&vq->vq_write_offset_tree, zio); 544 zio->io_queue_state = ZIO_QS_NONE; 545 } 546 547 static boolean_t 548 vdev_queue_is_interactive(zio_priority_t p) 549 { 550 switch (p) { 551 case ZIO_PRIORITY_SCRUB: 552 case ZIO_PRIORITY_REMOVAL: 553 case ZIO_PRIORITY_INITIALIZING: 554 case ZIO_PRIORITY_REBUILD: 555 return (B_FALSE); 556 default: 557 return (B_TRUE); 558 } 559 } 560 561 static void 562 vdev_queue_pending_add(vdev_queue_t *vq, zio_t *zio) 563 { 564 ASSERT(MUTEX_HELD(&vq->vq_lock)); 565 ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 566 vq->vq_cactive[zio->io_priority]++; 567 vq->vq_active++; 568 if (vdev_queue_is_interactive(zio->io_priority)) { 569 if (++vq->vq_ia_active == 1) 570 vq->vq_nia_credit = 1; 571 } else if (vq->vq_ia_active > 0) { 572 vq->vq_nia_credit--; 573 } 574 zio->io_queue_state = ZIO_QS_ACTIVE; 575 list_insert_tail(&vq->vq_active_list, zio); 576 } 577 578 static void 579 vdev_queue_pending_remove(vdev_queue_t *vq, zio_t *zio) 580 { 581 ASSERT(MUTEX_HELD(&vq->vq_lock)); 582 ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 583 vq->vq_cactive[zio->io_priority]--; 584 vq->vq_active--; 585 if (vdev_queue_is_interactive(zio->io_priority)) { 586 if (--vq->vq_ia_active == 0) 587 vq->vq_nia_credit = 0; 588 else 589 vq->vq_nia_credit = zfs_vdev_nia_credit; 590 } else if (vq->vq_ia_active == 0) 591 vq->vq_nia_credit++; 592 list_remove(&vq->vq_active_list, zio); 593 zio->io_queue_state = ZIO_QS_NONE; 594 } 595 596 static void 597 vdev_queue_agg_io_done(zio_t *aio) 598 { 599 abd_free(aio->io_abd); 600 } 601 602 /* 603 * Compute the range spanned by two i/os, which is the endpoint of the last 604 * (lio->io_offset + lio->io_size) minus start of the first (fio->io_offset). 605 * Conveniently, the gap between fio and lio is given by -IO_SPAN(lio, fio); 606 * thus fio and lio are adjacent if and only if IO_SPAN(lio, fio) == 0. 607 */ 608 #define IO_SPAN(fio, lio) ((lio)->io_offset + (lio)->io_size - (fio)->io_offset) 609 #define IO_GAP(fio, lio) (-IO_SPAN(lio, fio)) 610 611 /* 612 * Sufficiently adjacent io_offset's in ZIOs will be aggregated. We do this 613 * by creating a gang ABD from the adjacent ZIOs io_abd's. By using 614 * a gang ABD we avoid doing memory copies to and from the parent, 615 * child ZIOs. The gang ABD also accounts for gaps between adjacent 616 * io_offsets by simply getting the zero ABD for writes or allocating 617 * a new ABD for reads and placing them in the gang ABD as well. 618 */ 619 static zio_t * 620 vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio) 621 { 622 zio_t *first, *last, *aio, *dio, *mandatory, *nio; 623 uint64_t maxgap = 0; 624 uint64_t size; 625 uint64_t limit; 626 boolean_t stretch = B_FALSE; 627 uint64_t next_offset; 628 abd_t *abd; 629 avl_tree_t *t; 630 631 /* 632 * TRIM aggregation should not be needed since code in zfs_trim.c can 633 * submit TRIM I/O for extents up to zfs_trim_extent_bytes_max (128M). 634 */ 635 if (zio->io_type == ZIO_TYPE_TRIM) 636 return (NULL); 637 638 if (zio->io_flags & ZIO_FLAG_DONT_AGGREGATE) 639 return (NULL); 640 641 if (vq->vq_vdev->vdev_nonrot) 642 limit = zfs_vdev_aggregation_limit_non_rotating; 643 else 644 limit = zfs_vdev_aggregation_limit; 645 if (limit == 0) 646 return (NULL); 647 limit = MIN(limit, SPA_MAXBLOCKSIZE); 648 649 /* 650 * I/Os to distributed spares are directly dispatched to the dRAID 651 * leaf vdevs for aggregation. See the comment at the end of the 652 * zio_vdev_io_start() function. 653 */ 654 ASSERT(vq->vq_vdev->vdev_ops != &vdev_draid_spare_ops); 655 656 first = last = zio; 657 658 if (zio->io_type == ZIO_TYPE_READ) { 659 maxgap = zfs_vdev_read_gap_limit; 660 t = &vq->vq_read_offset_tree; 661 } else { 662 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 663 t = &vq->vq_write_offset_tree; 664 } 665 666 /* 667 * We can aggregate I/Os that are sufficiently adjacent and of 668 * the same flavor, as expressed by the AGG_INHERIT flags. 669 * The latter requirement is necessary so that certain 670 * attributes of the I/O, such as whether it's a normal I/O 671 * or a scrub/resilver, can be preserved in the aggregate. 672 * We can include optional I/Os, but don't allow them 673 * to begin a range as they add no benefit in that situation. 674 */ 675 676 /* 677 * We keep track of the last non-optional I/O. 678 */ 679 mandatory = (first->io_flags & ZIO_FLAG_OPTIONAL) ? NULL : first; 680 681 /* 682 * Walk backwards through sufficiently contiguous I/Os 683 * recording the last non-optional I/O. 684 */ 685 zio_flag_t flags = zio->io_flags & ZIO_FLAG_AGG_INHERIT; 686 while ((dio = AVL_PREV(t, first)) != NULL && 687 (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && 688 IO_SPAN(dio, last) <= limit && 689 IO_GAP(dio, first) <= maxgap && 690 dio->io_type == zio->io_type) { 691 first = dio; 692 if (mandatory == NULL && !(first->io_flags & ZIO_FLAG_OPTIONAL)) 693 mandatory = first; 694 } 695 696 /* 697 * Skip any initial optional I/Os. 698 */ 699 while ((first->io_flags & ZIO_FLAG_OPTIONAL) && first != last) { 700 first = AVL_NEXT(t, first); 701 ASSERT(first != NULL); 702 } 703 704 705 /* 706 * Walk forward through sufficiently contiguous I/Os. 707 * The aggregation limit does not apply to optional i/os, so that 708 * we can issue contiguous writes even if they are larger than the 709 * aggregation limit. 710 */ 711 while ((dio = AVL_NEXT(t, last)) != NULL && 712 (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && 713 (IO_SPAN(first, dio) <= limit || 714 (dio->io_flags & ZIO_FLAG_OPTIONAL)) && 715 IO_SPAN(first, dio) <= SPA_MAXBLOCKSIZE && 716 IO_GAP(last, dio) <= maxgap && 717 dio->io_type == zio->io_type) { 718 last = dio; 719 if (!(last->io_flags & ZIO_FLAG_OPTIONAL)) 720 mandatory = last; 721 } 722 723 /* 724 * Now that we've established the range of the I/O aggregation 725 * we must decide what to do with trailing optional I/Os. 726 * For reads, there's nothing to do. While we are unable to 727 * aggregate further, it's possible that a trailing optional 728 * I/O would allow the underlying device to aggregate with 729 * subsequent I/Os. We must therefore determine if the next 730 * non-optional I/O is close enough to make aggregation 731 * worthwhile. 732 */ 733 if (zio->io_type == ZIO_TYPE_WRITE && mandatory != NULL) { 734 zio_t *nio = last; 735 while ((dio = AVL_NEXT(t, nio)) != NULL && 736 IO_GAP(nio, dio) == 0 && 737 IO_GAP(mandatory, dio) <= zfs_vdev_write_gap_limit) { 738 nio = dio; 739 if (!(nio->io_flags & ZIO_FLAG_OPTIONAL)) { 740 stretch = B_TRUE; 741 break; 742 } 743 } 744 } 745 746 if (stretch) { 747 /* 748 * We are going to include an optional io in our aggregated 749 * span, thus closing the write gap. Only mandatory i/os can 750 * start aggregated spans, so make sure that the next i/o 751 * after our span is mandatory. 752 */ 753 dio = AVL_NEXT(t, last); 754 ASSERT3P(dio, !=, NULL); 755 dio->io_flags &= ~ZIO_FLAG_OPTIONAL; 756 } else { 757 /* do not include the optional i/o */ 758 while (last != mandatory && last != first) { 759 ASSERT(last->io_flags & ZIO_FLAG_OPTIONAL); 760 last = AVL_PREV(t, last); 761 ASSERT(last != NULL); 762 } 763 } 764 765 if (first == last) 766 return (NULL); 767 768 size = IO_SPAN(first, last); 769 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 770 771 abd = abd_alloc_gang(); 772 if (abd == NULL) 773 return (NULL); 774 775 aio = zio_vdev_delegated_io(first->io_vd, first->io_offset, 776 abd, size, first->io_type, zio->io_priority, 777 flags | ZIO_FLAG_DONT_QUEUE, vdev_queue_agg_io_done, NULL); 778 aio->io_timestamp = first->io_timestamp; 779 780 nio = first; 781 next_offset = first->io_offset; 782 do { 783 dio = nio; 784 nio = AVL_NEXT(t, dio); 785 ASSERT3P(dio, !=, NULL); 786 zio_add_child(dio, aio); 787 vdev_queue_io_remove(vq, dio); 788 789 if (dio->io_offset != next_offset) { 790 /* allocate a buffer for a read gap */ 791 ASSERT3U(dio->io_type, ==, ZIO_TYPE_READ); 792 ASSERT3U(dio->io_offset, >, next_offset); 793 abd = abd_alloc_for_io( 794 dio->io_offset - next_offset, B_TRUE); 795 abd_gang_add(aio->io_abd, abd, B_TRUE); 796 } 797 if (dio->io_abd && 798 (dio->io_size != abd_get_size(dio->io_abd))) { 799 /* abd size not the same as IO size */ 800 ASSERT3U(abd_get_size(dio->io_abd), >, dio->io_size); 801 abd = abd_get_offset_size(dio->io_abd, 0, dio->io_size); 802 abd_gang_add(aio->io_abd, abd, B_TRUE); 803 } else { 804 if (dio->io_flags & ZIO_FLAG_NODATA) { 805 /* allocate a buffer for a write gap */ 806 ASSERT3U(dio->io_type, ==, ZIO_TYPE_WRITE); 807 ASSERT3P(dio->io_abd, ==, NULL); 808 abd_gang_add(aio->io_abd, 809 abd_get_zeros(dio->io_size), B_TRUE); 810 } else { 811 /* 812 * We pass B_FALSE to abd_gang_add() 813 * because we did not allocate a new 814 * ABD, so it is assumed the caller 815 * will free this ABD. 816 */ 817 abd_gang_add(aio->io_abd, dio->io_abd, 818 B_FALSE); 819 } 820 } 821 next_offset = dio->io_offset + dio->io_size; 822 } while (dio != last); 823 ASSERT3U(abd_get_size(aio->io_abd), ==, aio->io_size); 824 825 /* 826 * Callers must call zio_vdev_io_bypass() and zio_execute() for 827 * aggregated (parent) I/Os so that we could avoid dropping the 828 * queue's lock here to avoid a deadlock that we could encounter 829 * due to lock order reversal between vq_lock and io_lock in 830 * zio_change_priority(). 831 */ 832 return (aio); 833 } 834 835 static zio_t * 836 vdev_queue_io_to_issue(vdev_queue_t *vq) 837 { 838 zio_t *zio, *aio; 839 zio_priority_t p; 840 avl_index_t idx; 841 avl_tree_t *tree; 842 843 again: 844 ASSERT(MUTEX_HELD(&vq->vq_lock)); 845 846 p = vdev_queue_class_to_issue(vq); 847 848 if (p == ZIO_PRIORITY_NUM_QUEUEABLE) { 849 /* No eligible queued i/os */ 850 return (NULL); 851 } 852 853 if (vdev_queue_class_fifo(p)) { 854 zio = list_head(&vq->vq_class[p].vqc_list); 855 } else { 856 /* 857 * For LBA-ordered queues (async / scrub / initializing), 858 * issue the I/O which follows the most recently issued I/O 859 * in LBA (offset) order, but to avoid starvation only within 860 * the same 0.5 second interval as the first I/O. 861 */ 862 tree = &vq->vq_class[p].vqc_tree; 863 zio = aio = avl_first(tree); 864 if (zio->io_offset < vq->vq_last_offset) { 865 vq->vq_io_search.io_timestamp = zio->io_timestamp; 866 vq->vq_io_search.io_offset = vq->vq_last_offset; 867 zio = avl_find(tree, &vq->vq_io_search, &idx); 868 if (zio == NULL) { 869 zio = avl_nearest(tree, idx, AVL_AFTER); 870 if (zio == NULL || 871 (zio->io_timestamp >> VDQ_T_SHIFT) != 872 (aio->io_timestamp >> VDQ_T_SHIFT)) 873 zio = aio; 874 } 875 } 876 } 877 ASSERT3U(zio->io_priority, ==, p); 878 879 aio = vdev_queue_aggregate(vq, zio); 880 if (aio != NULL) { 881 zio = aio; 882 } else { 883 vdev_queue_io_remove(vq, zio); 884 885 /* 886 * If the I/O is or was optional and therefore has no data, we 887 * need to simply discard it. We need to drop the vdev queue's 888 * lock to avoid a deadlock that we could encounter since this 889 * I/O will complete immediately. 890 */ 891 if (zio->io_flags & ZIO_FLAG_NODATA) { 892 mutex_exit(&vq->vq_lock); 893 zio_vdev_io_bypass(zio); 894 zio_execute(zio); 895 mutex_enter(&vq->vq_lock); 896 goto again; 897 } 898 } 899 900 vdev_queue_pending_add(vq, zio); 901 vq->vq_last_offset = zio->io_offset + zio->io_size; 902 903 return (zio); 904 } 905 906 zio_t * 907 vdev_queue_io(zio_t *zio) 908 { 909 vdev_queue_t *vq = &zio->io_vd->vdev_queue; 910 zio_t *dio, *nio; 911 zio_link_t *zl = NULL; 912 913 if (zio->io_flags & ZIO_FLAG_DONT_QUEUE) 914 return (zio); 915 916 /* 917 * Children i/os inherent their parent's priority, which might 918 * not match the child's i/o type. Fix it up here. 919 */ 920 if (zio->io_type == ZIO_TYPE_READ) { 921 ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); 922 923 if (zio->io_priority != ZIO_PRIORITY_SYNC_READ && 924 zio->io_priority != ZIO_PRIORITY_ASYNC_READ && 925 zio->io_priority != ZIO_PRIORITY_SCRUB && 926 zio->io_priority != ZIO_PRIORITY_REMOVAL && 927 zio->io_priority != ZIO_PRIORITY_INITIALIZING && 928 zio->io_priority != ZIO_PRIORITY_REBUILD) { 929 zio->io_priority = ZIO_PRIORITY_ASYNC_READ; 930 } 931 } else if (zio->io_type == ZIO_TYPE_WRITE) { 932 ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); 933 934 if (zio->io_priority != ZIO_PRIORITY_SYNC_WRITE && 935 zio->io_priority != ZIO_PRIORITY_ASYNC_WRITE && 936 zio->io_priority != ZIO_PRIORITY_REMOVAL && 937 zio->io_priority != ZIO_PRIORITY_INITIALIZING && 938 zio->io_priority != ZIO_PRIORITY_REBUILD) { 939 zio->io_priority = ZIO_PRIORITY_ASYNC_WRITE; 940 } 941 } else { 942 ASSERT(zio->io_type == ZIO_TYPE_TRIM); 943 ASSERT(zio->io_priority == ZIO_PRIORITY_TRIM); 944 } 945 946 zio->io_flags |= ZIO_FLAG_DONT_QUEUE; 947 zio->io_timestamp = gethrtime(); 948 949 mutex_enter(&vq->vq_lock); 950 vdev_queue_io_add(vq, zio); 951 nio = vdev_queue_io_to_issue(vq); 952 mutex_exit(&vq->vq_lock); 953 954 if (nio == NULL) 955 return (NULL); 956 957 if (nio->io_done == vdev_queue_agg_io_done) { 958 while ((dio = zio_walk_parents(nio, &zl)) != NULL) { 959 ASSERT3U(dio->io_type, ==, nio->io_type); 960 zio_vdev_io_bypass(dio); 961 zio_execute(dio); 962 } 963 zio_nowait(nio); 964 return (NULL); 965 } 966 967 return (nio); 968 } 969 970 void 971 vdev_queue_io_done(zio_t *zio) 972 { 973 vdev_queue_t *vq = &zio->io_vd->vdev_queue; 974 zio_t *dio, *nio; 975 zio_link_t *zl = NULL; 976 977 hrtime_t now = gethrtime(); 978 vq->vq_io_complete_ts = now; 979 vq->vq_io_delta_ts = zio->io_delta = now - zio->io_timestamp; 980 981 mutex_enter(&vq->vq_lock); 982 vdev_queue_pending_remove(vq, zio); 983 984 while ((nio = vdev_queue_io_to_issue(vq)) != NULL) { 985 mutex_exit(&vq->vq_lock); 986 if (nio->io_done == vdev_queue_agg_io_done) { 987 while ((dio = zio_walk_parents(nio, &zl)) != NULL) { 988 ASSERT3U(dio->io_type, ==, nio->io_type); 989 zio_vdev_io_bypass(dio); 990 zio_execute(dio); 991 } 992 zio_nowait(nio); 993 } else { 994 zio_vdev_io_reissue(nio); 995 zio_execute(nio); 996 } 997 mutex_enter(&vq->vq_lock); 998 } 999 1000 mutex_exit(&vq->vq_lock); 1001 } 1002 1003 void 1004 vdev_queue_change_io_priority(zio_t *zio, zio_priority_t priority) 1005 { 1006 vdev_queue_t *vq = &zio->io_vd->vdev_queue; 1007 1008 /* 1009 * ZIO_PRIORITY_NOW is used by the vdev cache code and the aggregate zio 1010 * code to issue IOs without adding them to the vdev queue. In this 1011 * case, the zio is already going to be issued as quickly as possible 1012 * and so it doesn't need any reprioritization to help. 1013 */ 1014 if (zio->io_priority == ZIO_PRIORITY_NOW) 1015 return; 1016 1017 ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 1018 ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 1019 1020 if (zio->io_type == ZIO_TYPE_READ) { 1021 if (priority != ZIO_PRIORITY_SYNC_READ && 1022 priority != ZIO_PRIORITY_ASYNC_READ && 1023 priority != ZIO_PRIORITY_SCRUB) 1024 priority = ZIO_PRIORITY_ASYNC_READ; 1025 } else { 1026 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 1027 if (priority != ZIO_PRIORITY_SYNC_WRITE && 1028 priority != ZIO_PRIORITY_ASYNC_WRITE) 1029 priority = ZIO_PRIORITY_ASYNC_WRITE; 1030 } 1031 1032 mutex_enter(&vq->vq_lock); 1033 1034 /* 1035 * If the zio is in none of the queues we can simply change 1036 * the priority. If the zio is waiting to be submitted we must 1037 * remove it from the queue and re-insert it with the new priority. 1038 * Otherwise, the zio is currently active and we cannot change its 1039 * priority. 1040 */ 1041 if (zio->io_queue_state == ZIO_QS_QUEUED) { 1042 vdev_queue_class_remove(vq, zio); 1043 zio->io_priority = priority; 1044 vdev_queue_class_add(vq, zio); 1045 } else if (zio->io_queue_state == ZIO_QS_NONE) { 1046 zio->io_priority = priority; 1047 } 1048 1049 mutex_exit(&vq->vq_lock); 1050 } 1051 1052 /* 1053 * As these two methods are only used for load calculations we're not 1054 * concerned if we get an incorrect value on 32bit platforms due to lack of 1055 * vq_lock mutex use here, instead we prefer to keep it lock free for 1056 * performance. 1057 */ 1058 uint32_t 1059 vdev_queue_length(vdev_t *vd) 1060 { 1061 return (vd->vdev_queue.vq_active); 1062 } 1063 1064 uint64_t 1065 vdev_queue_last_offset(vdev_t *vd) 1066 { 1067 return (vd->vdev_queue.vq_last_offset); 1068 } 1069 1070 uint64_t 1071 vdev_queue_class_length(vdev_t *vd, zio_priority_t p) 1072 { 1073 vdev_queue_t *vq = &vd->vdev_queue; 1074 if (vdev_queue_class_fifo(p)) 1075 return (vq->vq_class[p].vqc_list_numnodes); 1076 else 1077 return (avl_numnodes(&vq->vq_class[p].vqc_tree)); 1078 } 1079 1080 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, aggregation_limit, UINT, ZMOD_RW, 1081 "Max vdev I/O aggregation size"); 1082 1083 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, aggregation_limit_non_rotating, UINT, 1084 ZMOD_RW, "Max vdev I/O aggregation size for non-rotating media"); 1085 1086 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, read_gap_limit, UINT, ZMOD_RW, 1087 "Aggregate read I/O over gap"); 1088 1089 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, write_gap_limit, UINT, ZMOD_RW, 1090 "Aggregate write I/O over gap"); 1091 1092 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, max_active, UINT, ZMOD_RW, 1093 "Maximum number of active I/Os per vdev"); 1094 1095 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_active_max_dirty_percent, 1096 UINT, ZMOD_RW, "Async write concurrency max threshold"); 1097 1098 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_active_min_dirty_percent, 1099 UINT, ZMOD_RW, "Async write concurrency min threshold"); 1100 1101 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_read_max_active, UINT, ZMOD_RW, 1102 "Max active async read I/Os per vdev"); 1103 1104 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_read_min_active, UINT, ZMOD_RW, 1105 "Min active async read I/Os per vdev"); 1106 1107 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_max_active, UINT, ZMOD_RW, 1108 "Max active async write I/Os per vdev"); 1109 1110 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_min_active, UINT, ZMOD_RW, 1111 "Min active async write I/Os per vdev"); 1112 1113 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, initializing_max_active, UINT, ZMOD_RW, 1114 "Max active initializing I/Os per vdev"); 1115 1116 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, initializing_min_active, UINT, ZMOD_RW, 1117 "Min active initializing I/Os per vdev"); 1118 1119 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, removal_max_active, UINT, ZMOD_RW, 1120 "Max active removal I/Os per vdev"); 1121 1122 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, removal_min_active, UINT, ZMOD_RW, 1123 "Min active removal I/Os per vdev"); 1124 1125 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, scrub_max_active, UINT, ZMOD_RW, 1126 "Max active scrub I/Os per vdev"); 1127 1128 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, scrub_min_active, UINT, ZMOD_RW, 1129 "Min active scrub I/Os per vdev"); 1130 1131 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_read_max_active, UINT, ZMOD_RW, 1132 "Max active sync read I/Os per vdev"); 1133 1134 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_read_min_active, UINT, ZMOD_RW, 1135 "Min active sync read I/Os per vdev"); 1136 1137 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_write_max_active, UINT, ZMOD_RW, 1138 "Max active sync write I/Os per vdev"); 1139 1140 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_write_min_active, UINT, ZMOD_RW, 1141 "Min active sync write I/Os per vdev"); 1142 1143 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, trim_max_active, UINT, ZMOD_RW, 1144 "Max active trim/discard I/Os per vdev"); 1145 1146 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, trim_min_active, UINT, ZMOD_RW, 1147 "Min active trim/discard I/Os per vdev"); 1148 1149 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, rebuild_max_active, UINT, ZMOD_RW, 1150 "Max active rebuild I/Os per vdev"); 1151 1152 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, rebuild_min_active, UINT, ZMOD_RW, 1153 "Min active rebuild I/Os per vdev"); 1154 1155 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, nia_credit, UINT, ZMOD_RW, 1156 "Number of non-interactive I/Os to allow in sequence"); 1157 1158 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, nia_delay, UINT, ZMOD_RW, 1159 "Number of non-interactive I/Os before _max_active"); 1160 1161 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, queue_depth_pct, UINT, ZMOD_RW, 1162 "Queue depth percentage for each top-level vdev"); 1163 1164 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, def_queue_depth, UINT, ZMOD_RW, 1165 "Default queue depth for each allocator"); 1166