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 else 279 avl_add(&vq->vq_class[p].vqc_tree, zio); 280 } 281 282 static void 283 vdev_queue_class_remove(vdev_queue_t *vq, zio_t *zio) 284 { 285 zio_priority_t p = zio->io_priority; 286 uint32_t empty; 287 if (vdev_queue_class_fifo(p)) { 288 list_t *list = &vq->vq_class[p].vqc_list; 289 list_remove(list, zio); 290 empty = list_is_empty(list); 291 } else { 292 avl_tree_t *tree = &vq->vq_class[p].vqc_tree; 293 avl_remove(tree, zio); 294 empty = avl_is_empty(tree); 295 } 296 vq->vq_cqueued &= ~(empty << p); 297 } 298 299 static uint_t 300 vdev_queue_class_min_active(vdev_queue_t *vq, zio_priority_t p) 301 { 302 switch (p) { 303 case ZIO_PRIORITY_SYNC_READ: 304 return (zfs_vdev_sync_read_min_active); 305 case ZIO_PRIORITY_SYNC_WRITE: 306 return (zfs_vdev_sync_write_min_active); 307 case ZIO_PRIORITY_ASYNC_READ: 308 return (zfs_vdev_async_read_min_active); 309 case ZIO_PRIORITY_ASYNC_WRITE: 310 return (zfs_vdev_async_write_min_active); 311 case ZIO_PRIORITY_SCRUB: 312 return (vq->vq_ia_active == 0 ? zfs_vdev_scrub_min_active : 313 MIN(vq->vq_nia_credit, zfs_vdev_scrub_min_active)); 314 case ZIO_PRIORITY_REMOVAL: 315 return (vq->vq_ia_active == 0 ? zfs_vdev_removal_min_active : 316 MIN(vq->vq_nia_credit, zfs_vdev_removal_min_active)); 317 case ZIO_PRIORITY_INITIALIZING: 318 return (vq->vq_ia_active == 0 ?zfs_vdev_initializing_min_active: 319 MIN(vq->vq_nia_credit, zfs_vdev_initializing_min_active)); 320 case ZIO_PRIORITY_TRIM: 321 return (zfs_vdev_trim_min_active); 322 case ZIO_PRIORITY_REBUILD: 323 return (vq->vq_ia_active == 0 ? zfs_vdev_rebuild_min_active : 324 MIN(vq->vq_nia_credit, zfs_vdev_rebuild_min_active)); 325 default: 326 panic("invalid priority %u", p); 327 return (0); 328 } 329 } 330 331 static uint_t 332 vdev_queue_max_async_writes(spa_t *spa) 333 { 334 uint_t writes; 335 uint64_t dirty = 0; 336 dsl_pool_t *dp = spa_get_dsl(spa); 337 uint64_t min_bytes = zfs_dirty_data_max * 338 zfs_vdev_async_write_active_min_dirty_percent / 100; 339 uint64_t max_bytes = zfs_dirty_data_max * 340 zfs_vdev_async_write_active_max_dirty_percent / 100; 341 342 /* 343 * Async writes may occur before the assignment of the spa's 344 * dsl_pool_t if a self-healing zio is issued prior to the 345 * completion of dmu_objset_open_impl(). 346 */ 347 if (dp == NULL) 348 return (zfs_vdev_async_write_max_active); 349 350 /* 351 * Sync tasks correspond to interactive user actions. To reduce the 352 * execution time of those actions we push data out as fast as possible. 353 */ 354 dirty = dp->dp_dirty_total; 355 if (dirty > max_bytes || spa_has_pending_synctask(spa)) 356 return (zfs_vdev_async_write_max_active); 357 358 if (dirty < min_bytes) 359 return (zfs_vdev_async_write_min_active); 360 361 /* 362 * linear interpolation: 363 * slope = (max_writes - min_writes) / (max_bytes - min_bytes) 364 * move right by min_bytes 365 * move up by min_writes 366 */ 367 writes = (dirty - min_bytes) * 368 (zfs_vdev_async_write_max_active - 369 zfs_vdev_async_write_min_active) / 370 (max_bytes - min_bytes) + 371 zfs_vdev_async_write_min_active; 372 ASSERT3U(writes, >=, zfs_vdev_async_write_min_active); 373 ASSERT3U(writes, <=, zfs_vdev_async_write_max_active); 374 return (writes); 375 } 376 377 static uint_t 378 vdev_queue_class_max_active(vdev_queue_t *vq, zio_priority_t p) 379 { 380 switch (p) { 381 case ZIO_PRIORITY_SYNC_READ: 382 return (zfs_vdev_sync_read_max_active); 383 case ZIO_PRIORITY_SYNC_WRITE: 384 return (zfs_vdev_sync_write_max_active); 385 case ZIO_PRIORITY_ASYNC_READ: 386 return (zfs_vdev_async_read_max_active); 387 case ZIO_PRIORITY_ASYNC_WRITE: 388 return (vdev_queue_max_async_writes(vq->vq_vdev->vdev_spa)); 389 case ZIO_PRIORITY_SCRUB: 390 if (vq->vq_ia_active > 0) { 391 return (MIN(vq->vq_nia_credit, 392 zfs_vdev_scrub_min_active)); 393 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 394 return (MAX(1, zfs_vdev_scrub_min_active)); 395 return (zfs_vdev_scrub_max_active); 396 case ZIO_PRIORITY_REMOVAL: 397 if (vq->vq_ia_active > 0) { 398 return (MIN(vq->vq_nia_credit, 399 zfs_vdev_removal_min_active)); 400 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 401 return (MAX(1, zfs_vdev_removal_min_active)); 402 return (zfs_vdev_removal_max_active); 403 case ZIO_PRIORITY_INITIALIZING: 404 if (vq->vq_ia_active > 0) { 405 return (MIN(vq->vq_nia_credit, 406 zfs_vdev_initializing_min_active)); 407 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 408 return (MAX(1, zfs_vdev_initializing_min_active)); 409 return (zfs_vdev_initializing_max_active); 410 case ZIO_PRIORITY_TRIM: 411 return (zfs_vdev_trim_max_active); 412 case ZIO_PRIORITY_REBUILD: 413 if (vq->vq_ia_active > 0) { 414 return (MIN(vq->vq_nia_credit, 415 zfs_vdev_rebuild_min_active)); 416 } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) 417 return (MAX(1, zfs_vdev_rebuild_min_active)); 418 return (zfs_vdev_rebuild_max_active); 419 default: 420 panic("invalid priority %u", p); 421 return (0); 422 } 423 } 424 425 /* 426 * Return the i/o class to issue from, or ZIO_PRIORITY_NUM_QUEUEABLE if 427 * there is no eligible class. 428 */ 429 static zio_priority_t 430 vdev_queue_class_to_issue(vdev_queue_t *vq) 431 { 432 uint32_t cq = vq->vq_cqueued; 433 zio_priority_t p, p1; 434 435 if (cq == 0 || vq->vq_active >= zfs_vdev_max_active) 436 return (ZIO_PRIORITY_NUM_QUEUEABLE); 437 438 /* 439 * Find a queue that has not reached its minimum # outstanding i/os. 440 * Do round-robin to reduce starvation due to zfs_vdev_max_active 441 * and vq_nia_credit limits. 442 */ 443 p1 = vq->vq_last_prio + 1; 444 if (p1 >= ZIO_PRIORITY_NUM_QUEUEABLE) 445 p1 = 0; 446 for (p = p1; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 447 if ((cq & (1U << p)) != 0 && vq->vq_cactive[p] < 448 vdev_queue_class_min_active(vq, p)) 449 goto found; 450 } 451 for (p = 0; p < p1; p++) { 452 if ((cq & (1U << p)) != 0 && vq->vq_cactive[p] < 453 vdev_queue_class_min_active(vq, p)) 454 goto found; 455 } 456 457 /* 458 * If we haven't found a queue, look for one that hasn't reached its 459 * maximum # outstanding i/os. 460 */ 461 for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 462 if ((cq & (1U << p)) != 0 && vq->vq_cactive[p] < 463 vdev_queue_class_max_active(vq, p)) 464 break; 465 } 466 467 found: 468 vq->vq_last_prio = p; 469 return (p); 470 } 471 472 void 473 vdev_queue_init(vdev_t *vd) 474 { 475 vdev_queue_t *vq = &vd->vdev_queue; 476 zio_priority_t p; 477 478 vq->vq_vdev = vd; 479 480 for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 481 if (vdev_queue_class_fifo(p)) { 482 list_create(&vq->vq_class[p].vqc_list, 483 sizeof (zio_t), 484 offsetof(struct zio, io_queue_node.l)); 485 } else { 486 avl_create(&vq->vq_class[p].vqc_tree, 487 vdev_queue_to_compare, sizeof (zio_t), 488 offsetof(struct zio, io_queue_node.a)); 489 } 490 } 491 avl_create(&vq->vq_read_offset_tree, 492 vdev_queue_offset_compare, sizeof (zio_t), 493 offsetof(struct zio, io_offset_node)); 494 avl_create(&vq->vq_write_offset_tree, 495 vdev_queue_offset_compare, sizeof (zio_t), 496 offsetof(struct zio, io_offset_node)); 497 498 vq->vq_last_offset = 0; 499 list_create(&vq->vq_active_list, sizeof (struct zio), 500 offsetof(struct zio, io_queue_node.l)); 501 mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL); 502 } 503 504 void 505 vdev_queue_fini(vdev_t *vd) 506 { 507 vdev_queue_t *vq = &vd->vdev_queue; 508 509 for (zio_priority_t p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { 510 if (vdev_queue_class_fifo(p)) 511 list_destroy(&vq->vq_class[p].vqc_list); 512 else 513 avl_destroy(&vq->vq_class[p].vqc_tree); 514 } 515 avl_destroy(&vq->vq_read_offset_tree); 516 avl_destroy(&vq->vq_write_offset_tree); 517 518 list_destroy(&vq->vq_active_list); 519 mutex_destroy(&vq->vq_lock); 520 } 521 522 static void 523 vdev_queue_io_add(vdev_queue_t *vq, zio_t *zio) 524 { 525 zio->io_queue_state = ZIO_QS_QUEUED; 526 vdev_queue_class_add(vq, zio); 527 if (zio->io_type == ZIO_TYPE_READ) 528 avl_add(&vq->vq_read_offset_tree, zio); 529 else if (zio->io_type == ZIO_TYPE_WRITE) 530 avl_add(&vq->vq_write_offset_tree, zio); 531 } 532 533 static void 534 vdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio) 535 { 536 vdev_queue_class_remove(vq, zio); 537 if (zio->io_type == ZIO_TYPE_READ) 538 avl_remove(&vq->vq_read_offset_tree, zio); 539 else if (zio->io_type == ZIO_TYPE_WRITE) 540 avl_remove(&vq->vq_write_offset_tree, zio); 541 zio->io_queue_state = ZIO_QS_NONE; 542 } 543 544 static boolean_t 545 vdev_queue_is_interactive(zio_priority_t p) 546 { 547 switch (p) { 548 case ZIO_PRIORITY_SCRUB: 549 case ZIO_PRIORITY_REMOVAL: 550 case ZIO_PRIORITY_INITIALIZING: 551 case ZIO_PRIORITY_REBUILD: 552 return (B_FALSE); 553 default: 554 return (B_TRUE); 555 } 556 } 557 558 static void 559 vdev_queue_pending_add(vdev_queue_t *vq, zio_t *zio) 560 { 561 ASSERT(MUTEX_HELD(&vq->vq_lock)); 562 ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 563 vq->vq_cactive[zio->io_priority]++; 564 vq->vq_active++; 565 if (vdev_queue_is_interactive(zio->io_priority)) { 566 if (++vq->vq_ia_active == 1) 567 vq->vq_nia_credit = 1; 568 } else if (vq->vq_ia_active > 0) { 569 vq->vq_nia_credit--; 570 } 571 zio->io_queue_state = ZIO_QS_ACTIVE; 572 list_insert_tail(&vq->vq_active_list, zio); 573 } 574 575 static void 576 vdev_queue_pending_remove(vdev_queue_t *vq, zio_t *zio) 577 { 578 ASSERT(MUTEX_HELD(&vq->vq_lock)); 579 ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 580 vq->vq_cactive[zio->io_priority]--; 581 vq->vq_active--; 582 if (vdev_queue_is_interactive(zio->io_priority)) { 583 if (--vq->vq_ia_active == 0) 584 vq->vq_nia_credit = 0; 585 else 586 vq->vq_nia_credit = zfs_vdev_nia_credit; 587 } else if (vq->vq_ia_active == 0) 588 vq->vq_nia_credit++; 589 list_remove(&vq->vq_active_list, zio); 590 zio->io_queue_state = ZIO_QS_NONE; 591 } 592 593 static void 594 vdev_queue_agg_io_done(zio_t *aio) 595 { 596 abd_free(aio->io_abd); 597 } 598 599 /* 600 * Compute the range spanned by two i/os, which is the endpoint of the last 601 * (lio->io_offset + lio->io_size) minus start of the first (fio->io_offset). 602 * Conveniently, the gap between fio and lio is given by -IO_SPAN(lio, fio); 603 * thus fio and lio are adjacent if and only if IO_SPAN(lio, fio) == 0. 604 */ 605 #define IO_SPAN(fio, lio) ((lio)->io_offset + (lio)->io_size - (fio)->io_offset) 606 #define IO_GAP(fio, lio) (-IO_SPAN(lio, fio)) 607 608 /* 609 * Sufficiently adjacent io_offset's in ZIOs will be aggregated. We do this 610 * by creating a gang ABD from the adjacent ZIOs io_abd's. By using 611 * a gang ABD we avoid doing memory copies to and from the parent, 612 * child ZIOs. The gang ABD also accounts for gaps between adjacent 613 * io_offsets by simply getting the zero ABD for writes or allocating 614 * a new ABD for reads and placing them in the gang ABD as well. 615 */ 616 static zio_t * 617 vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio) 618 { 619 zio_t *first, *last, *aio, *dio, *mandatory, *nio; 620 uint64_t maxgap = 0; 621 uint64_t size; 622 uint64_t limit; 623 boolean_t stretch = B_FALSE; 624 uint64_t next_offset; 625 abd_t *abd; 626 avl_tree_t *t; 627 628 /* 629 * TRIM aggregation should not be needed since code in zfs_trim.c can 630 * submit TRIM I/O for extents up to zfs_trim_extent_bytes_max (128M). 631 */ 632 if (zio->io_type == ZIO_TYPE_TRIM) 633 return (NULL); 634 635 if (zio->io_flags & ZIO_FLAG_DONT_AGGREGATE) 636 return (NULL); 637 638 if (vq->vq_vdev->vdev_nonrot) 639 limit = zfs_vdev_aggregation_limit_non_rotating; 640 else 641 limit = zfs_vdev_aggregation_limit; 642 if (limit == 0) 643 return (NULL); 644 limit = MIN(limit, SPA_MAXBLOCKSIZE); 645 646 /* 647 * I/Os to distributed spares are directly dispatched to the dRAID 648 * leaf vdevs for aggregation. See the comment at the end of the 649 * zio_vdev_io_start() function. 650 */ 651 ASSERT(vq->vq_vdev->vdev_ops != &vdev_draid_spare_ops); 652 653 first = last = zio; 654 655 if (zio->io_type == ZIO_TYPE_READ) { 656 maxgap = zfs_vdev_read_gap_limit; 657 t = &vq->vq_read_offset_tree; 658 } else { 659 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 660 t = &vq->vq_write_offset_tree; 661 } 662 663 /* 664 * We can aggregate I/Os that are sufficiently adjacent and of 665 * the same flavor, as expressed by the AGG_INHERIT flags. 666 * The latter requirement is necessary so that certain 667 * attributes of the I/O, such as whether it's a normal I/O 668 * or a scrub/resilver, can be preserved in the aggregate. 669 * We can include optional I/Os, but don't allow them 670 * to begin a range as they add no benefit in that situation. 671 */ 672 673 /* 674 * We keep track of the last non-optional I/O. 675 */ 676 mandatory = (first->io_flags & ZIO_FLAG_OPTIONAL) ? NULL : first; 677 678 /* 679 * Walk backwards through sufficiently contiguous I/Os 680 * recording the last non-optional I/O. 681 */ 682 zio_flag_t flags = zio->io_flags & ZIO_FLAG_AGG_INHERIT; 683 while ((dio = AVL_PREV(t, first)) != NULL && 684 (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && 685 IO_SPAN(dio, last) <= limit && 686 IO_GAP(dio, first) <= maxgap && 687 dio->io_type == zio->io_type) { 688 first = dio; 689 if (mandatory == NULL && !(first->io_flags & ZIO_FLAG_OPTIONAL)) 690 mandatory = first; 691 } 692 693 /* 694 * Skip any initial optional I/Os. 695 */ 696 while ((first->io_flags & ZIO_FLAG_OPTIONAL) && first != last) { 697 first = AVL_NEXT(t, first); 698 ASSERT(first != NULL); 699 } 700 701 702 /* 703 * Walk forward through sufficiently contiguous I/Os. 704 * The aggregation limit does not apply to optional i/os, so that 705 * we can issue contiguous writes even if they are larger than the 706 * aggregation limit. 707 */ 708 while ((dio = AVL_NEXT(t, last)) != NULL && 709 (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && 710 (IO_SPAN(first, dio) <= limit || 711 (dio->io_flags & ZIO_FLAG_OPTIONAL)) && 712 IO_SPAN(first, dio) <= SPA_MAXBLOCKSIZE && 713 IO_GAP(last, dio) <= maxgap && 714 dio->io_type == zio->io_type) { 715 last = dio; 716 if (!(last->io_flags & ZIO_FLAG_OPTIONAL)) 717 mandatory = last; 718 } 719 720 /* 721 * Now that we've established the range of the I/O aggregation 722 * we must decide what to do with trailing optional I/Os. 723 * For reads, there's nothing to do. While we are unable to 724 * aggregate further, it's possible that a trailing optional 725 * I/O would allow the underlying device to aggregate with 726 * subsequent I/Os. We must therefore determine if the next 727 * non-optional I/O is close enough to make aggregation 728 * worthwhile. 729 */ 730 if (zio->io_type == ZIO_TYPE_WRITE && mandatory != NULL) { 731 zio_t *nio = last; 732 while ((dio = AVL_NEXT(t, nio)) != NULL && 733 IO_GAP(nio, dio) == 0 && 734 IO_GAP(mandatory, dio) <= zfs_vdev_write_gap_limit) { 735 nio = dio; 736 if (!(nio->io_flags & ZIO_FLAG_OPTIONAL)) { 737 stretch = B_TRUE; 738 break; 739 } 740 } 741 } 742 743 if (stretch) { 744 /* 745 * We are going to include an optional io in our aggregated 746 * span, thus closing the write gap. Only mandatory i/os can 747 * start aggregated spans, so make sure that the next i/o 748 * after our span is mandatory. 749 */ 750 dio = AVL_NEXT(t, last); 751 ASSERT3P(dio, !=, NULL); 752 dio->io_flags &= ~ZIO_FLAG_OPTIONAL; 753 } else { 754 /* do not include the optional i/o */ 755 while (last != mandatory && last != first) { 756 ASSERT(last->io_flags & ZIO_FLAG_OPTIONAL); 757 last = AVL_PREV(t, last); 758 ASSERT(last != NULL); 759 } 760 } 761 762 if (first == last) 763 return (NULL); 764 765 size = IO_SPAN(first, last); 766 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 767 768 abd = abd_alloc_gang(); 769 if (abd == NULL) 770 return (NULL); 771 772 aio = zio_vdev_delegated_io(first->io_vd, first->io_offset, 773 abd, size, first->io_type, zio->io_priority, 774 flags | ZIO_FLAG_DONT_QUEUE, vdev_queue_agg_io_done, NULL); 775 aio->io_timestamp = first->io_timestamp; 776 777 nio = first; 778 next_offset = first->io_offset; 779 do { 780 dio = nio; 781 nio = AVL_NEXT(t, dio); 782 ASSERT3P(dio, !=, NULL); 783 zio_add_child(dio, aio); 784 vdev_queue_io_remove(vq, dio); 785 786 if (dio->io_offset != next_offset) { 787 /* allocate a buffer for a read gap */ 788 ASSERT3U(dio->io_type, ==, ZIO_TYPE_READ); 789 ASSERT3U(dio->io_offset, >, next_offset); 790 abd = abd_alloc_for_io( 791 dio->io_offset - next_offset, B_TRUE); 792 abd_gang_add(aio->io_abd, abd, B_TRUE); 793 } 794 if (dio->io_abd && 795 (dio->io_size != abd_get_size(dio->io_abd))) { 796 /* abd size not the same as IO size */ 797 ASSERT3U(abd_get_size(dio->io_abd), >, dio->io_size); 798 abd = abd_get_offset_size(dio->io_abd, 0, dio->io_size); 799 abd_gang_add(aio->io_abd, abd, B_TRUE); 800 } else { 801 if (dio->io_flags & ZIO_FLAG_NODATA) { 802 /* allocate a buffer for a write gap */ 803 ASSERT3U(dio->io_type, ==, ZIO_TYPE_WRITE); 804 ASSERT3P(dio->io_abd, ==, NULL); 805 abd_gang_add(aio->io_abd, 806 abd_get_zeros(dio->io_size), B_TRUE); 807 } else { 808 /* 809 * We pass B_FALSE to abd_gang_add() 810 * because we did not allocate a new 811 * ABD, so it is assumed the caller 812 * will free this ABD. 813 */ 814 abd_gang_add(aio->io_abd, dio->io_abd, 815 B_FALSE); 816 } 817 } 818 next_offset = dio->io_offset + dio->io_size; 819 } while (dio != last); 820 ASSERT3U(abd_get_size(aio->io_abd), ==, aio->io_size); 821 822 /* 823 * Callers must call zio_vdev_io_bypass() and zio_execute() for 824 * aggregated (parent) I/Os so that we could avoid dropping the 825 * queue's lock here to avoid a deadlock that we could encounter 826 * due to lock order reversal between vq_lock and io_lock in 827 * zio_change_priority(). 828 */ 829 return (aio); 830 } 831 832 static zio_t * 833 vdev_queue_io_to_issue(vdev_queue_t *vq) 834 { 835 zio_t *zio, *aio; 836 zio_priority_t p; 837 avl_index_t idx; 838 avl_tree_t *tree; 839 840 again: 841 ASSERT(MUTEX_HELD(&vq->vq_lock)); 842 843 p = vdev_queue_class_to_issue(vq); 844 845 if (p == ZIO_PRIORITY_NUM_QUEUEABLE) { 846 /* No eligible queued i/os */ 847 return (NULL); 848 } 849 850 if (vdev_queue_class_fifo(p)) { 851 zio = list_head(&vq->vq_class[p].vqc_list); 852 } else { 853 /* 854 * For LBA-ordered queues (async / scrub / initializing), 855 * issue the I/O which follows the most recently issued I/O 856 * in LBA (offset) order, but to avoid starvation only within 857 * the same 0.5 second interval as the first I/O. 858 */ 859 tree = &vq->vq_class[p].vqc_tree; 860 zio = aio = avl_first(tree); 861 if (zio->io_offset < vq->vq_last_offset) { 862 vq->vq_io_search.io_timestamp = zio->io_timestamp; 863 vq->vq_io_search.io_offset = vq->vq_last_offset; 864 zio = avl_find(tree, &vq->vq_io_search, &idx); 865 if (zio == NULL) { 866 zio = avl_nearest(tree, idx, AVL_AFTER); 867 if (zio == NULL || 868 (zio->io_timestamp >> VDQ_T_SHIFT) != 869 (aio->io_timestamp >> VDQ_T_SHIFT)) 870 zio = aio; 871 } 872 } 873 } 874 ASSERT3U(zio->io_priority, ==, p); 875 876 aio = vdev_queue_aggregate(vq, zio); 877 if (aio != NULL) { 878 zio = aio; 879 } else { 880 vdev_queue_io_remove(vq, zio); 881 882 /* 883 * If the I/O is or was optional and therefore has no data, we 884 * need to simply discard it. We need to drop the vdev queue's 885 * lock to avoid a deadlock that we could encounter since this 886 * I/O will complete immediately. 887 */ 888 if (zio->io_flags & ZIO_FLAG_NODATA) { 889 mutex_exit(&vq->vq_lock); 890 zio_vdev_io_bypass(zio); 891 zio_execute(zio); 892 mutex_enter(&vq->vq_lock); 893 goto again; 894 } 895 } 896 897 vdev_queue_pending_add(vq, zio); 898 vq->vq_last_offset = zio->io_offset + zio->io_size; 899 900 return (zio); 901 } 902 903 zio_t * 904 vdev_queue_io(zio_t *zio) 905 { 906 vdev_queue_t *vq = &zio->io_vd->vdev_queue; 907 zio_t *dio, *nio; 908 zio_link_t *zl = NULL; 909 910 if (zio->io_flags & ZIO_FLAG_DONT_QUEUE) 911 return (zio); 912 913 /* 914 * Children i/os inherent their parent's priority, which might 915 * not match the child's i/o type. Fix it up here. 916 */ 917 if (zio->io_type == ZIO_TYPE_READ) { 918 ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); 919 920 if (zio->io_priority != ZIO_PRIORITY_SYNC_READ && 921 zio->io_priority != ZIO_PRIORITY_ASYNC_READ && 922 zio->io_priority != ZIO_PRIORITY_SCRUB && 923 zio->io_priority != ZIO_PRIORITY_REMOVAL && 924 zio->io_priority != ZIO_PRIORITY_INITIALIZING && 925 zio->io_priority != ZIO_PRIORITY_REBUILD) { 926 zio->io_priority = ZIO_PRIORITY_ASYNC_READ; 927 } 928 } else if (zio->io_type == ZIO_TYPE_WRITE) { 929 ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); 930 931 if (zio->io_priority != ZIO_PRIORITY_SYNC_WRITE && 932 zio->io_priority != ZIO_PRIORITY_ASYNC_WRITE && 933 zio->io_priority != ZIO_PRIORITY_REMOVAL && 934 zio->io_priority != ZIO_PRIORITY_INITIALIZING && 935 zio->io_priority != ZIO_PRIORITY_REBUILD) { 936 zio->io_priority = ZIO_PRIORITY_ASYNC_WRITE; 937 } 938 } else { 939 ASSERT(zio->io_type == ZIO_TYPE_TRIM); 940 ASSERT(zio->io_priority == ZIO_PRIORITY_TRIM); 941 } 942 943 zio->io_flags |= ZIO_FLAG_DONT_QUEUE; 944 zio->io_timestamp = gethrtime(); 945 946 mutex_enter(&vq->vq_lock); 947 vdev_queue_io_add(vq, zio); 948 nio = vdev_queue_io_to_issue(vq); 949 mutex_exit(&vq->vq_lock); 950 951 if (nio == NULL) 952 return (NULL); 953 954 if (nio->io_done == vdev_queue_agg_io_done) { 955 while ((dio = zio_walk_parents(nio, &zl)) != NULL) { 956 ASSERT3U(dio->io_type, ==, nio->io_type); 957 zio_vdev_io_bypass(dio); 958 zio_execute(dio); 959 } 960 zio_nowait(nio); 961 return (NULL); 962 } 963 964 return (nio); 965 } 966 967 void 968 vdev_queue_io_done(zio_t *zio) 969 { 970 vdev_queue_t *vq = &zio->io_vd->vdev_queue; 971 zio_t *dio, *nio; 972 zio_link_t *zl = NULL; 973 974 hrtime_t now = gethrtime(); 975 vq->vq_io_complete_ts = now; 976 vq->vq_io_delta_ts = zio->io_delta = now - zio->io_timestamp; 977 978 mutex_enter(&vq->vq_lock); 979 vdev_queue_pending_remove(vq, zio); 980 981 while ((nio = vdev_queue_io_to_issue(vq)) != NULL) { 982 mutex_exit(&vq->vq_lock); 983 if (nio->io_done == vdev_queue_agg_io_done) { 984 while ((dio = zio_walk_parents(nio, &zl)) != NULL) { 985 ASSERT3U(dio->io_type, ==, nio->io_type); 986 zio_vdev_io_bypass(dio); 987 zio_execute(dio); 988 } 989 zio_nowait(nio); 990 } else { 991 zio_vdev_io_reissue(nio); 992 zio_execute(nio); 993 } 994 mutex_enter(&vq->vq_lock); 995 } 996 997 mutex_exit(&vq->vq_lock); 998 } 999 1000 void 1001 vdev_queue_change_io_priority(zio_t *zio, zio_priority_t priority) 1002 { 1003 vdev_queue_t *vq = &zio->io_vd->vdev_queue; 1004 1005 /* 1006 * ZIO_PRIORITY_NOW is used by the vdev cache code and the aggregate zio 1007 * code to issue IOs without adding them to the vdev queue. In this 1008 * case, the zio is already going to be issued as quickly as possible 1009 * and so it doesn't need any reprioritization to help. 1010 */ 1011 if (zio->io_priority == ZIO_PRIORITY_NOW) 1012 return; 1013 1014 ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 1015 ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 1016 1017 if (zio->io_type == ZIO_TYPE_READ) { 1018 if (priority != ZIO_PRIORITY_SYNC_READ && 1019 priority != ZIO_PRIORITY_ASYNC_READ && 1020 priority != ZIO_PRIORITY_SCRUB) 1021 priority = ZIO_PRIORITY_ASYNC_READ; 1022 } else { 1023 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 1024 if (priority != ZIO_PRIORITY_SYNC_WRITE && 1025 priority != ZIO_PRIORITY_ASYNC_WRITE) 1026 priority = ZIO_PRIORITY_ASYNC_WRITE; 1027 } 1028 1029 mutex_enter(&vq->vq_lock); 1030 1031 /* 1032 * If the zio is in none of the queues we can simply change 1033 * the priority. If the zio is waiting to be submitted we must 1034 * remove it from the queue and re-insert it with the new priority. 1035 * Otherwise, the zio is currently active and we cannot change its 1036 * priority. 1037 */ 1038 if (zio->io_queue_state == ZIO_QS_QUEUED) { 1039 vdev_queue_class_remove(vq, zio); 1040 zio->io_priority = priority; 1041 vdev_queue_class_add(vq, zio); 1042 } else if (zio->io_queue_state == ZIO_QS_NONE) { 1043 zio->io_priority = priority; 1044 } 1045 1046 mutex_exit(&vq->vq_lock); 1047 } 1048 1049 /* 1050 * As these two methods are only used for load calculations we're not 1051 * concerned if we get an incorrect value on 32bit platforms due to lack of 1052 * vq_lock mutex use here, instead we prefer to keep it lock free for 1053 * performance. 1054 */ 1055 uint32_t 1056 vdev_queue_length(vdev_t *vd) 1057 { 1058 return (vd->vdev_queue.vq_active); 1059 } 1060 1061 uint64_t 1062 vdev_queue_last_offset(vdev_t *vd) 1063 { 1064 return (vd->vdev_queue.vq_last_offset); 1065 } 1066 1067 uint64_t 1068 vdev_queue_class_length(vdev_t *vd, zio_priority_t p) 1069 { 1070 vdev_queue_t *vq = &vd->vdev_queue; 1071 if (vdev_queue_class_fifo(p)) 1072 return (list_is_empty(&vq->vq_class[p].vqc_list) == 0); 1073 else 1074 return (avl_numnodes(&vq->vq_class[p].vqc_tree)); 1075 } 1076 1077 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, aggregation_limit, UINT, ZMOD_RW, 1078 "Max vdev I/O aggregation size"); 1079 1080 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, aggregation_limit_non_rotating, UINT, 1081 ZMOD_RW, "Max vdev I/O aggregation size for non-rotating media"); 1082 1083 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, read_gap_limit, UINT, ZMOD_RW, 1084 "Aggregate read I/O over gap"); 1085 1086 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, write_gap_limit, UINT, ZMOD_RW, 1087 "Aggregate write I/O over gap"); 1088 1089 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, max_active, UINT, ZMOD_RW, 1090 "Maximum number of active I/Os per vdev"); 1091 1092 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_active_max_dirty_percent, 1093 UINT, ZMOD_RW, "Async write concurrency max threshold"); 1094 1095 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_active_min_dirty_percent, 1096 UINT, ZMOD_RW, "Async write concurrency min threshold"); 1097 1098 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_read_max_active, UINT, ZMOD_RW, 1099 "Max active async read I/Os per vdev"); 1100 1101 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_read_min_active, UINT, ZMOD_RW, 1102 "Min active async read I/Os per vdev"); 1103 1104 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_max_active, UINT, ZMOD_RW, 1105 "Max active async write I/Os per vdev"); 1106 1107 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_min_active, UINT, ZMOD_RW, 1108 "Min active async write I/Os per vdev"); 1109 1110 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, initializing_max_active, UINT, ZMOD_RW, 1111 "Max active initializing I/Os per vdev"); 1112 1113 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, initializing_min_active, UINT, ZMOD_RW, 1114 "Min active initializing I/Os per vdev"); 1115 1116 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, removal_max_active, UINT, ZMOD_RW, 1117 "Max active removal I/Os per vdev"); 1118 1119 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, removal_min_active, UINT, ZMOD_RW, 1120 "Min active removal I/Os per vdev"); 1121 1122 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, scrub_max_active, UINT, ZMOD_RW, 1123 "Max active scrub I/Os per vdev"); 1124 1125 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, scrub_min_active, UINT, ZMOD_RW, 1126 "Min active scrub I/Os per vdev"); 1127 1128 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_read_max_active, UINT, ZMOD_RW, 1129 "Max active sync read I/Os per vdev"); 1130 1131 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_read_min_active, UINT, ZMOD_RW, 1132 "Min active sync read I/Os per vdev"); 1133 1134 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_write_max_active, UINT, ZMOD_RW, 1135 "Max active sync write I/Os per vdev"); 1136 1137 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_write_min_active, UINT, ZMOD_RW, 1138 "Min active sync write I/Os per vdev"); 1139 1140 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, trim_max_active, UINT, ZMOD_RW, 1141 "Max active trim/discard I/Os per vdev"); 1142 1143 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, trim_min_active, UINT, ZMOD_RW, 1144 "Min active trim/discard I/Os per vdev"); 1145 1146 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, rebuild_max_active, UINT, ZMOD_RW, 1147 "Max active rebuild I/Os per vdev"); 1148 1149 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, rebuild_min_active, UINT, ZMOD_RW, 1150 "Min active rebuild I/Os per vdev"); 1151 1152 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, nia_credit, UINT, ZMOD_RW, 1153 "Number of non-interactive I/Os to allow in sequence"); 1154 1155 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, nia_delay, UINT, ZMOD_RW, 1156 "Number of non-interactive I/Os before _max_active"); 1157 1158 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, queue_depth_pct, UINT, ZMOD_RW, 1159 "Queue depth percentage for each top-level vdev"); 1160 1161 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, def_queue_depth, UINT, ZMOD_RW, 1162 "Default queue depth for each allocator"); 1163