| /* |
| * CDDL HEADER START |
| * |
| * The contents of this file are subject to the terms of the |
| * Common Development and Distribution License (the "License"). |
| * You may not use this file except in compliance with the License. |
| * |
| * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
| * or http://www.opensolaris.org/os/licensing. |
| * See the License for the specific language governing permissions |
| * and limitations under the License. |
| * |
| * When distributing Covered Code, include this CDDL HEADER in each |
| * file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
| * If applicable, add the following below this CDDL HEADER, with the |
| * fields enclosed by brackets "[]" replaced with your own identifying |
| * information: Portions Copyright [yyyy] [name of copyright owner] |
| * |
| * CDDL HEADER END |
| */ |
| /* |
| * Copyright 2009 Sun Microsystems, Inc. All rights reserved. |
| * Use is subject to license terms. |
| */ |
| |
| /* |
| * Copyright (c) 2012, 2018 by Delphix. All rights reserved. |
| */ |
| |
| #include <sys/zfs_context.h> |
| #include <sys/vdev_impl.h> |
| #include <sys/spa_impl.h> |
| #include <sys/zio.h> |
| #include <sys/avl.h> |
| #include <sys/dsl_pool.h> |
| #include <sys/metaslab_impl.h> |
| #include <sys/spa.h> |
| #include <sys/spa_impl.h> |
| #include <sys/kstat.h> |
| #include <sys/abd.h> |
| |
| /* |
| * ZFS I/O Scheduler |
| * --------------- |
| * |
| * ZFS issues I/O operations to leaf vdevs to satisfy and complete zios. The |
| * I/O scheduler determines when and in what order those operations are |
| * issued. The I/O scheduler divides operations into five I/O classes |
| * prioritized in the following order: sync read, sync write, async read, |
| * async write, and scrub/resilver. Each queue defines the minimum and |
| * maximum number of concurrent operations that may be issued to the device. |
| * In addition, the device has an aggregate maximum. Note that the sum of the |
| * per-queue minimums must not exceed the aggregate maximum. If the |
| * sum of the per-queue maximums exceeds the aggregate maximum, then the |
| * number of active i/os may reach zfs_vdev_max_active, in which case no |
| * further i/os will be issued regardless of whether all per-queue |
| * minimums have been met. |
| * |
| * For many physical devices, throughput increases with the number of |
| * concurrent operations, but latency typically suffers. Further, physical |
| * devices typically have a limit at which more concurrent operations have no |
| * effect on throughput or can actually cause it to decrease. |
| * |
| * The scheduler selects the next operation to issue by first looking for an |
| * I/O class whose minimum has not been satisfied. Once all are satisfied and |
| * the aggregate maximum has not been hit, the scheduler looks for classes |
| * whose maximum has not been satisfied. Iteration through the I/O classes is |
| * done in the order specified above. No further operations are issued if the |
| * aggregate maximum number of concurrent operations has been hit or if there |
| * are no operations queued for an I/O class that has not hit its maximum. |
| * Every time an i/o is queued or an operation completes, the I/O scheduler |
| * looks for new operations to issue. |
| * |
| * All I/O classes have a fixed maximum number of outstanding operations |
| * except for the async write class. Asynchronous writes represent the data |
| * that is committed to stable storage during the syncing stage for |
| * transaction groups (see txg.c). Transaction groups enter the syncing state |
| * periodically so the number of queued async writes will quickly burst up and |
| * then bleed down to zero. Rather than servicing them as quickly as possible, |
| * the I/O scheduler changes the maximum number of active async write i/os |
| * according to the amount of dirty data in the pool (see dsl_pool.c). Since |
| * both throughput and latency typically increase with the number of |
| * concurrent operations issued to physical devices, reducing the burstiness |
| * in the number of concurrent operations also stabilizes the response time of |
| * operations from other -- and in particular synchronous -- queues. In broad |
| * strokes, the I/O scheduler will issue more concurrent operations from the |
| * async write queue as there's more dirty data in the pool. |
| * |
| * Async Writes |
| * |
| * The number of concurrent operations issued for the async write I/O class |
| * follows a piece-wise linear function defined by a few adjustable points. |
| * |
| * | o---------| <-- zfs_vdev_async_write_max_active |
| * ^ | /^ | |
| * | | / | | |
| * active | / | | |
| * I/O | / | | |
| * count | / | | |
| * | / | | |
| * |------------o | | <-- zfs_vdev_async_write_min_active |
| * 0|____________^______|_________| |
| * 0% | | 100% of zfs_dirty_data_max |
| * | | |
| * | `-- zfs_vdev_async_write_active_max_dirty_percent |
| * `--------- zfs_vdev_async_write_active_min_dirty_percent |
| * |
| * Until the amount of dirty data exceeds a minimum percentage of the dirty |
| * data allowed in the pool, the I/O scheduler will limit the number of |
| * concurrent operations to the minimum. As that threshold is crossed, the |
| * number of concurrent operations issued increases linearly to the maximum at |
| * the specified maximum percentage of the dirty data allowed in the pool. |
| * |
| * Ideally, the amount of dirty data on a busy pool will stay in the sloped |
| * part of the function between zfs_vdev_async_write_active_min_dirty_percent |
| * and zfs_vdev_async_write_active_max_dirty_percent. If it exceeds the |
| * maximum percentage, this indicates that the rate of incoming data is |
| * greater than the rate that the backend storage can handle. In this case, we |
| * must further throttle incoming writes (see dmu_tx_delay() for details). |
| */ |
| |
| /* |
| * The maximum number of i/os active to each device. Ideally, this will be >= |
| * the sum of each queue's max_active. It must be at least the sum of each |
| * queue's min_active. |
| */ |
| uint32_t zfs_vdev_max_active = 1000; |
| |
| /* |
| * Per-queue limits on the number of i/os active to each device. If the |
| * number of active i/os is < zfs_vdev_max_active, then the min_active comes |
| * into play. We will send min_active from each queue, and then select from |
| * queues in the order defined by zio_priority_t. |
| * |
| * In general, smaller max_active's will lead to lower latency of synchronous |
| * operations. Larger max_active's may lead to higher overall throughput, |
| * depending on underlying storage. |
| * |
| * The ratio of the queues' max_actives determines the balance of performance |
| * between reads, writes, and scrubs. E.g., increasing |
| * zfs_vdev_scrub_max_active will cause the scrub or resilver to complete |
| * more quickly, but reads and writes to have higher latency and lower |
| * throughput. |
| */ |
| uint32_t zfs_vdev_sync_read_min_active = 10; |
| uint32_t zfs_vdev_sync_read_max_active = 10; |
| uint32_t zfs_vdev_sync_write_min_active = 10; |
| uint32_t zfs_vdev_sync_write_max_active = 10; |
| uint32_t zfs_vdev_async_read_min_active = 1; |
| uint32_t zfs_vdev_async_read_max_active = 3; |
| uint32_t zfs_vdev_async_write_min_active = 2; |
| uint32_t zfs_vdev_async_write_max_active = 10; |
| uint32_t zfs_vdev_scrub_min_active = 1; |
| uint32_t zfs_vdev_scrub_max_active = 2; |
| uint32_t zfs_vdev_removal_min_active = 1; |
| uint32_t zfs_vdev_removal_max_active = 2; |
| uint32_t zfs_vdev_initializing_min_active = 1; |
| uint32_t zfs_vdev_initializing_max_active = 1; |
| uint32_t zfs_vdev_trim_min_active = 1; |
| uint32_t zfs_vdev_trim_max_active = 2; |
| |
| /* |
| * When the pool has less than zfs_vdev_async_write_active_min_dirty_percent |
| * dirty data, use zfs_vdev_async_write_min_active. When it has more than |
| * zfs_vdev_async_write_active_max_dirty_percent, use |
| * zfs_vdev_async_write_max_active. The value is linearly interpolated |
| * between min and max. |
| */ |
| int zfs_vdev_async_write_active_min_dirty_percent = 30; |
| int zfs_vdev_async_write_active_max_dirty_percent = 60; |
| |
| /* |
| * To reduce IOPs, we aggregate small adjacent I/Os into one large I/O. |
| * For read I/Os, we also aggregate across small adjacency gaps; for writes |
| * we include spans of optional I/Os to aid aggregation at the disk even when |
| * they aren't able to help us aggregate at this level. |
| */ |
| int zfs_vdev_aggregation_limit = 1 << 20; |
| int zfs_vdev_aggregation_limit_non_rotating = SPA_OLD_MAXBLOCKSIZE; |
| int zfs_vdev_read_gap_limit = 32 << 10; |
| int zfs_vdev_write_gap_limit = 4 << 10; |
| |
| /* |
| * Define the queue depth percentage for each top-level. This percentage is |
| * used in conjunction with zfs_vdev_async_max_active to determine how many |
| * allocations a specific top-level vdev should handle. Once the queue depth |
| * reaches zfs_vdev_queue_depth_pct * zfs_vdev_async_write_max_active / 100 |
| * then allocator will stop allocating blocks on that top-level device. |
| * The default kernel setting is 1000% which will yield 100 allocations per |
| * device. For userland testing, the default setting is 300% which equates |
| * to 30 allocations per device. |
| */ |
| #ifdef _KERNEL |
| int zfs_vdev_queue_depth_pct = 1000; |
| #else |
| int zfs_vdev_queue_depth_pct = 300; |
| #endif |
| |
| /* |
| * When performing allocations for a given metaslab, we want to make sure that |
| * there are enough IOs to aggregate together to improve throughput. We want to |
| * ensure that there are at least 128k worth of IOs that can be aggregated, and |
| * we assume that the average allocation size is 4k, so we need the queue depth |
| * to be 32 per allocator to get good aggregation of sequential writes. |
| */ |
| int zfs_vdev_def_queue_depth = 32; |
| |
| /* |
| * Allow TRIM I/Os to be aggregated. This should normally not be needed since |
| * TRIM I/O for extents up to zfs_trim_extent_bytes_max (128M) can be submitted |
| * by the TRIM code in zfs_trim.c. |
| */ |
| int zfs_vdev_aggregate_trim = 0; |
| |
| int |
| vdev_queue_offset_compare(const void *x1, const void *x2) |
| { |
| const zio_t *z1 = (const zio_t *)x1; |
| const zio_t *z2 = (const zio_t *)x2; |
| |
| int cmp = AVL_CMP(z1->io_offset, z2->io_offset); |
| |
| if (likely(cmp)) |
| return (cmp); |
| |
| return (AVL_PCMP(z1, z2)); |
| } |
| |
| static inline avl_tree_t * |
| vdev_queue_class_tree(vdev_queue_t *vq, zio_priority_t p) |
| { |
| return (&vq->vq_class[p].vqc_queued_tree); |
| } |
| |
| static inline avl_tree_t * |
| vdev_queue_type_tree(vdev_queue_t *vq, zio_type_t t) |
| { |
| ASSERT(t == ZIO_TYPE_READ || t == ZIO_TYPE_WRITE || t == ZIO_TYPE_TRIM); |
| if (t == ZIO_TYPE_READ) |
| return (&vq->vq_read_offset_tree); |
| else if (t == ZIO_TYPE_WRITE) |
| return (&vq->vq_write_offset_tree); |
| else |
| return (&vq->vq_trim_offset_tree); |
| } |
| |
| int |
| vdev_queue_timestamp_compare(const void *x1, const void *x2) |
| { |
| const zio_t *z1 = (const zio_t *)x1; |
| const zio_t *z2 = (const zio_t *)x2; |
| |
| int cmp = AVL_CMP(z1->io_timestamp, z2->io_timestamp); |
| |
| if (likely(cmp)) |
| return (cmp); |
| |
| return (AVL_PCMP(z1, z2)); |
| } |
| |
| static int |
| vdev_queue_class_min_active(zio_priority_t p) |
| { |
| switch (p) { |
| case ZIO_PRIORITY_SYNC_READ: |
| return (zfs_vdev_sync_read_min_active); |
| case ZIO_PRIORITY_SYNC_WRITE: |
| return (zfs_vdev_sync_write_min_active); |
| case ZIO_PRIORITY_ASYNC_READ: |
| return (zfs_vdev_async_read_min_active); |
| case ZIO_PRIORITY_ASYNC_WRITE: |
| return (zfs_vdev_async_write_min_active); |
| case ZIO_PRIORITY_SCRUB: |
| return (zfs_vdev_scrub_min_active); |
| case ZIO_PRIORITY_REMOVAL: |
| return (zfs_vdev_removal_min_active); |
| case ZIO_PRIORITY_INITIALIZING: |
| return (zfs_vdev_initializing_min_active); |
| case ZIO_PRIORITY_TRIM: |
| return (zfs_vdev_trim_min_active); |
| default: |
| panic("invalid priority %u", p); |
| return (0); |
| } |
| } |
| |
| static int |
| vdev_queue_max_async_writes(spa_t *spa) |
| { |
| int writes; |
| uint64_t dirty = 0; |
| dsl_pool_t *dp = spa_get_dsl(spa); |
| uint64_t min_bytes = zfs_dirty_data_max * |
| zfs_vdev_async_write_active_min_dirty_percent / 100; |
| uint64_t max_bytes = zfs_dirty_data_max * |
| zfs_vdev_async_write_active_max_dirty_percent / 100; |
| |
| /* |
| * Async writes may occur before the assignment of the spa's |
| * dsl_pool_t if a self-healing zio is issued prior to the |
| * completion of dmu_objset_open_impl(). |
| */ |
| if (dp == NULL) |
| return (zfs_vdev_async_write_max_active); |
| |
| /* |
| * Sync tasks correspond to interactive user actions. To reduce the |
| * execution time of those actions we push data out as fast as possible. |
| */ |
| if (spa_has_pending_synctask(spa)) |
| return (zfs_vdev_async_write_max_active); |
| |
| dirty = dp->dp_dirty_total; |
| if (dirty < min_bytes) |
| return (zfs_vdev_async_write_min_active); |
| if (dirty > max_bytes) |
| return (zfs_vdev_async_write_max_active); |
| |
| /* |
| * linear interpolation: |
| * slope = (max_writes - min_writes) / (max_bytes - min_bytes) |
| * move right by min_bytes |
| * move up by min_writes |
| */ |
| writes = (dirty - min_bytes) * |
| (zfs_vdev_async_write_max_active - |
| zfs_vdev_async_write_min_active) / |
| (max_bytes - min_bytes) + |
| zfs_vdev_async_write_min_active; |
| ASSERT3U(writes, >=, zfs_vdev_async_write_min_active); |
| ASSERT3U(writes, <=, zfs_vdev_async_write_max_active); |
| return (writes); |
| } |
| |
| static int |
| vdev_queue_class_max_active(spa_t *spa, zio_priority_t p) |
| { |
| switch (p) { |
| case ZIO_PRIORITY_SYNC_READ: |
| return (zfs_vdev_sync_read_max_active); |
| case ZIO_PRIORITY_SYNC_WRITE: |
| return (zfs_vdev_sync_write_max_active); |
| case ZIO_PRIORITY_ASYNC_READ: |
| return (zfs_vdev_async_read_max_active); |
| case ZIO_PRIORITY_ASYNC_WRITE: |
| return (vdev_queue_max_async_writes(spa)); |
| case ZIO_PRIORITY_SCRUB: |
| return (zfs_vdev_scrub_max_active); |
| case ZIO_PRIORITY_REMOVAL: |
| return (zfs_vdev_removal_max_active); |
| case ZIO_PRIORITY_INITIALIZING: |
| return (zfs_vdev_initializing_max_active); |
| case ZIO_PRIORITY_TRIM: |
| return (zfs_vdev_trim_max_active); |
| default: |
| panic("invalid priority %u", p); |
| return (0); |
| } |
| } |
| |
| /* |
| * Return the i/o class to issue from, or ZIO_PRIORITY_MAX_QUEUEABLE if |
| * there is no eligible class. |
| */ |
| static zio_priority_t |
| vdev_queue_class_to_issue(vdev_queue_t *vq) |
| { |
| spa_t *spa = vq->vq_vdev->vdev_spa; |
| zio_priority_t p; |
| |
| if (avl_numnodes(&vq->vq_active_tree) >= zfs_vdev_max_active) |
| return (ZIO_PRIORITY_NUM_QUEUEABLE); |
| |
| /* find a queue that has not reached its minimum # outstanding i/os */ |
| for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { |
| if (avl_numnodes(vdev_queue_class_tree(vq, p)) > 0 && |
| vq->vq_class[p].vqc_active < |
| vdev_queue_class_min_active(p)) |
| return (p); |
| } |
| |
| /* |
| * If we haven't found a queue, look for one that hasn't reached its |
| * maximum # outstanding i/os. |
| */ |
| for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { |
| if (avl_numnodes(vdev_queue_class_tree(vq, p)) > 0 && |
| vq->vq_class[p].vqc_active < |
| vdev_queue_class_max_active(spa, p)) |
| return (p); |
| } |
| |
| /* No eligible queued i/os */ |
| return (ZIO_PRIORITY_NUM_QUEUEABLE); |
| } |
| |
| void |
| vdev_queue_init(vdev_t *vd) |
| { |
| vdev_queue_t *vq = &vd->vdev_queue; |
| zio_priority_t p; |
| |
| mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL); |
| vq->vq_vdev = vd; |
| taskq_init_ent(&vd->vdev_queue.vq_io_search.io_tqent); |
| |
| avl_create(&vq->vq_active_tree, vdev_queue_offset_compare, |
| sizeof (zio_t), offsetof(struct zio, io_queue_node)); |
| avl_create(vdev_queue_type_tree(vq, ZIO_TYPE_READ), |
| vdev_queue_offset_compare, sizeof (zio_t), |
| offsetof(struct zio, io_offset_node)); |
| avl_create(vdev_queue_type_tree(vq, ZIO_TYPE_WRITE), |
| vdev_queue_offset_compare, sizeof (zio_t), |
| offsetof(struct zio, io_offset_node)); |
| avl_create(vdev_queue_type_tree(vq, ZIO_TYPE_TRIM), |
| vdev_queue_offset_compare, sizeof (zio_t), |
| offsetof(struct zio, io_offset_node)); |
| |
| for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { |
| int (*compfn) (const void *, const void *); |
| |
| /* |
| * The synchronous/trim i/o queues are dispatched in FIFO rather |
| * than LBA order. This provides more consistent latency for |
| * these i/os. |
| */ |
| if (p == ZIO_PRIORITY_SYNC_READ || |
| p == ZIO_PRIORITY_SYNC_WRITE || |
| p == ZIO_PRIORITY_TRIM) { |
| compfn = vdev_queue_timestamp_compare; |
| } else { |
| compfn = vdev_queue_offset_compare; |
| } |
| avl_create(vdev_queue_class_tree(vq, p), compfn, |
| sizeof (zio_t), offsetof(struct zio, io_queue_node)); |
| } |
| |
| vq->vq_last_offset = 0; |
| } |
| |
| void |
| vdev_queue_fini(vdev_t *vd) |
| { |
| vdev_queue_t *vq = &vd->vdev_queue; |
| |
| for (zio_priority_t p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) |
| avl_destroy(vdev_queue_class_tree(vq, p)); |
| avl_destroy(&vq->vq_active_tree); |
| avl_destroy(vdev_queue_type_tree(vq, ZIO_TYPE_READ)); |
| avl_destroy(vdev_queue_type_tree(vq, ZIO_TYPE_WRITE)); |
| avl_destroy(vdev_queue_type_tree(vq, ZIO_TYPE_TRIM)); |
| |
| mutex_destroy(&vq->vq_lock); |
| } |
| |
| static void |
| vdev_queue_io_add(vdev_queue_t *vq, zio_t *zio) |
| { |
| spa_t *spa = zio->io_spa; |
| spa_history_kstat_t *shk = &spa->spa_stats.io_history; |
| |
| ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); |
| avl_add(vdev_queue_class_tree(vq, zio->io_priority), zio); |
| avl_add(vdev_queue_type_tree(vq, zio->io_type), zio); |
| |
| if (shk->kstat != NULL) { |
| mutex_enter(&shk->lock); |
| kstat_waitq_enter(shk->kstat->ks_data); |
| mutex_exit(&shk->lock); |
| } |
| } |
| |
| static void |
| vdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio) |
| { |
| spa_t *spa = zio->io_spa; |
| spa_history_kstat_t *shk = &spa->spa_stats.io_history; |
| |
| ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); |
| avl_remove(vdev_queue_class_tree(vq, zio->io_priority), zio); |
| avl_remove(vdev_queue_type_tree(vq, zio->io_type), zio); |
| |
| if (shk->kstat != NULL) { |
| mutex_enter(&shk->lock); |
| kstat_waitq_exit(shk->kstat->ks_data); |
| mutex_exit(&shk->lock); |
| } |
| } |
| |
| static void |
| vdev_queue_pending_add(vdev_queue_t *vq, zio_t *zio) |
| { |
| spa_t *spa = zio->io_spa; |
| spa_history_kstat_t *shk = &spa->spa_stats.io_history; |
| |
| ASSERT(MUTEX_HELD(&vq->vq_lock)); |
| ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); |
| vq->vq_class[zio->io_priority].vqc_active++; |
| avl_add(&vq->vq_active_tree, zio); |
| |
| if (shk->kstat != NULL) { |
| mutex_enter(&shk->lock); |
| kstat_runq_enter(shk->kstat->ks_data); |
| mutex_exit(&shk->lock); |
| } |
| } |
| |
| static void |
| vdev_queue_pending_remove(vdev_queue_t *vq, zio_t *zio) |
| { |
| spa_t *spa = zio->io_spa; |
| spa_history_kstat_t *shk = &spa->spa_stats.io_history; |
| |
| ASSERT(MUTEX_HELD(&vq->vq_lock)); |
| ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); |
| vq->vq_class[zio->io_priority].vqc_active--; |
| avl_remove(&vq->vq_active_tree, zio); |
| |
| if (shk->kstat != NULL) { |
| kstat_io_t *ksio = shk->kstat->ks_data; |
| |
| mutex_enter(&shk->lock); |
| kstat_runq_exit(ksio); |
| if (zio->io_type == ZIO_TYPE_READ) { |
| ksio->reads++; |
| ksio->nread += zio->io_size; |
| } else if (zio->io_type == ZIO_TYPE_WRITE) { |
| ksio->writes++; |
| ksio->nwritten += zio->io_size; |
| } |
| mutex_exit(&shk->lock); |
| } |
| } |
| |
| static void |
| vdev_queue_agg_io_done(zio_t *aio) |
| { |
| if (aio->io_type == ZIO_TYPE_READ) { |
| zio_t *pio; |
| zio_link_t *zl = NULL; |
| while ((pio = zio_walk_parents(aio, &zl)) != NULL) { |
| abd_copy_off(pio->io_abd, aio->io_abd, |
| 0, pio->io_offset - aio->io_offset, pio->io_size); |
| } |
| } |
| |
| abd_free(aio->io_abd); |
| } |
| |
| /* |
| * Compute the range spanned by two i/os, which is the endpoint of the last |
| * (lio->io_offset + lio->io_size) minus start of the first (fio->io_offset). |
| * Conveniently, the gap between fio and lio is given by -IO_SPAN(lio, fio); |
| * thus fio and lio are adjacent if and only if IO_SPAN(lio, fio) == 0. |
| */ |
| #define IO_SPAN(fio, lio) ((lio)->io_offset + (lio)->io_size - (fio)->io_offset) |
| #define IO_GAP(fio, lio) (-IO_SPAN(lio, fio)) |
| |
| static zio_t * |
| vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio) |
| { |
| zio_t *first, *last, *aio, *dio, *mandatory, *nio; |
| zio_link_t *zl = NULL; |
| uint64_t maxgap = 0; |
| uint64_t size; |
| uint64_t limit; |
| int maxblocksize; |
| boolean_t stretch = B_FALSE; |
| avl_tree_t *t = vdev_queue_type_tree(vq, zio->io_type); |
| enum zio_flag flags = zio->io_flags & ZIO_FLAG_AGG_INHERIT; |
| abd_t *abd; |
| |
| maxblocksize = spa_maxblocksize(vq->vq_vdev->vdev_spa); |
| if (vq->vq_vdev->vdev_nonrot) |
| limit = zfs_vdev_aggregation_limit_non_rotating; |
| else |
| limit = zfs_vdev_aggregation_limit; |
| limit = MAX(MIN(limit, maxblocksize), 0); |
| |
| if (zio->io_flags & ZIO_FLAG_DONT_AGGREGATE || limit == 0) |
| return (NULL); |
| |
| /* |
| * While TRIM commands could be aggregated based on offset this |
| * behavior is disabled until it's determined to be beneficial. |
| */ |
| if (zio->io_type == ZIO_TYPE_TRIM && !zfs_vdev_aggregate_trim) |
| return (NULL); |
| |
| first = last = zio; |
| |
| if (zio->io_type == ZIO_TYPE_READ) |
| maxgap = zfs_vdev_read_gap_limit; |
| |
| /* |
| * We can aggregate I/Os that are sufficiently adjacent and of |
| * the same flavor, as expressed by the AGG_INHERIT flags. |
| * The latter requirement is necessary so that certain |
| * attributes of the I/O, such as whether it's a normal I/O |
| * or a scrub/resilver, can be preserved in the aggregate. |
| * We can include optional I/Os, but don't allow them |
| * to begin a range as they add no benefit in that situation. |
| */ |
| |
| /* |
| * We keep track of the last non-optional I/O. |
| */ |
| mandatory = (first->io_flags & ZIO_FLAG_OPTIONAL) ? NULL : first; |
| |
| /* |
| * Walk backwards through sufficiently contiguous I/Os |
| * recording the last non-optional I/O. |
| */ |
| while ((dio = AVL_PREV(t, first)) != NULL && |
| (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && |
| IO_SPAN(dio, last) <= limit && |
| IO_GAP(dio, first) <= maxgap && |
| dio->io_type == zio->io_type) { |
| first = dio; |
| if (mandatory == NULL && !(first->io_flags & ZIO_FLAG_OPTIONAL)) |
| mandatory = first; |
| } |
| |
| /* |
| * Skip any initial optional I/Os. |
| */ |
| while ((first->io_flags & ZIO_FLAG_OPTIONAL) && first != last) { |
| first = AVL_NEXT(t, first); |
| ASSERT(first != NULL); |
| } |
| |
| |
| /* |
| * Walk forward through sufficiently contiguous I/Os. |
| * The aggregation limit does not apply to optional i/os, so that |
| * we can issue contiguous writes even if they are larger than the |
| * aggregation limit. |
| */ |
| while ((dio = AVL_NEXT(t, last)) != NULL && |
| (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && |
| (IO_SPAN(first, dio) <= limit || |
| (dio->io_flags & ZIO_FLAG_OPTIONAL)) && |
| IO_SPAN(first, dio) <= maxblocksize && |
| IO_GAP(last, dio) <= maxgap && |
| dio->io_type == zio->io_type) { |
| last = dio; |
| if (!(last->io_flags & ZIO_FLAG_OPTIONAL)) |
| mandatory = last; |
| } |
| |
| /* |
| * Now that we've established the range of the I/O aggregation |
| * we must decide what to do with trailing optional I/Os. |
| * For reads, there's nothing to do. While we are unable to |
| * aggregate further, it's possible that a trailing optional |
| * I/O would allow the underlying device to aggregate with |
| * subsequent I/Os. We must therefore determine if the next |
| * non-optional I/O is close enough to make aggregation |
| * worthwhile. |
| */ |
| if (zio->io_type == ZIO_TYPE_WRITE && mandatory != NULL) { |
| zio_t *nio = last; |
| while ((dio = AVL_NEXT(t, nio)) != NULL && |
| IO_GAP(nio, dio) == 0 && |
| IO_GAP(mandatory, dio) <= zfs_vdev_write_gap_limit) { |
| nio = dio; |
| if (!(nio->io_flags & ZIO_FLAG_OPTIONAL)) { |
| stretch = B_TRUE; |
| break; |
| } |
| } |
| } |
| |
| if (stretch) { |
| /* |
| * We are going to include an optional io in our aggregated |
| * span, thus closing the write gap. Only mandatory i/os can |
| * start aggregated spans, so make sure that the next i/o |
| * after our span is mandatory. |
| */ |
| dio = AVL_NEXT(t, last); |
| dio->io_flags &= ~ZIO_FLAG_OPTIONAL; |
| } else { |
| /* do not include the optional i/o */ |
| while (last != mandatory && last != first) { |
| ASSERT(last->io_flags & ZIO_FLAG_OPTIONAL); |
| last = AVL_PREV(t, last); |
| ASSERT(last != NULL); |
| } |
| } |
| |
| if (first == last) |
| return (NULL); |
| |
| size = IO_SPAN(first, last); |
| ASSERT3U(size, <=, maxblocksize); |
| |
| abd = abd_alloc_for_io(size, B_TRUE); |
| if (abd == NULL) |
| return (NULL); |
| |
| aio = zio_vdev_delegated_io(first->io_vd, first->io_offset, |
| abd, size, first->io_type, zio->io_priority, |
| flags | ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE, |
| vdev_queue_agg_io_done, NULL); |
| aio->io_timestamp = first->io_timestamp; |
| |
| nio = first; |
| do { |
| dio = nio; |
| nio = AVL_NEXT(t, dio); |
| zio_add_child(dio, aio); |
| vdev_queue_io_remove(vq, dio); |
| } while (dio != last); |
| |
| /* |
| * We need to drop the vdev queue's lock during zio_execute() to |
| * avoid a deadlock that we could encounter due to lock order |
| * reversal between vq_lock and io_lock in zio_change_priority(). |
| * Use the dropped lock to do memory copy without congestion. |
| */ |
| mutex_exit(&vq->vq_lock); |
| while ((dio = zio_walk_parents(aio, &zl)) != NULL) { |
| ASSERT3U(dio->io_type, ==, aio->io_type); |
| |
| if (dio->io_flags & ZIO_FLAG_NODATA) { |
| ASSERT3U(dio->io_type, ==, ZIO_TYPE_WRITE); |
| abd_zero_off(aio->io_abd, |
| dio->io_offset - aio->io_offset, dio->io_size); |
| } else if (dio->io_type == ZIO_TYPE_WRITE) { |
| abd_copy_off(aio->io_abd, dio->io_abd, |
| dio->io_offset - aio->io_offset, 0, dio->io_size); |
| } |
| |
| zio_vdev_io_bypass(dio); |
| zio_execute(dio); |
| } |
| mutex_enter(&vq->vq_lock); |
| |
| return (aio); |
| } |
| |
| static zio_t * |
| vdev_queue_io_to_issue(vdev_queue_t *vq) |
| { |
| zio_t *zio, *aio; |
| zio_priority_t p; |
| avl_index_t idx; |
| avl_tree_t *tree; |
| |
| again: |
| ASSERT(MUTEX_HELD(&vq->vq_lock)); |
| |
| p = vdev_queue_class_to_issue(vq); |
| |
| if (p == ZIO_PRIORITY_NUM_QUEUEABLE) { |
| /* No eligible queued i/os */ |
| return (NULL); |
| } |
| |
| /* |
| * For LBA-ordered queues (async / scrub / initializing), issue the |
| * i/o which follows the most recently issued i/o in LBA (offset) order. |
| * |
| * For FIFO queues (sync/trim), issue the i/o with the lowest timestamp. |
| */ |
| tree = vdev_queue_class_tree(vq, p); |
| vq->vq_io_search.io_timestamp = 0; |
| vq->vq_io_search.io_offset = vq->vq_last_offset - 1; |
| VERIFY3P(avl_find(tree, &vq->vq_io_search, &idx), ==, NULL); |
| zio = avl_nearest(tree, idx, AVL_AFTER); |
| if (zio == NULL) |
| zio = avl_first(tree); |
| ASSERT3U(zio->io_priority, ==, p); |
| |
| aio = vdev_queue_aggregate(vq, zio); |
| if (aio != NULL) |
| zio = aio; |
| else |
| vdev_queue_io_remove(vq, zio); |
| |
| /* |
| * If the I/O is or was optional and therefore has no data, we need to |
| * simply discard it. We need to drop the vdev queue's lock to avoid a |
| * deadlock that we could encounter since this I/O will complete |
| * immediately. |
| */ |
| if (zio->io_flags & ZIO_FLAG_NODATA) { |
| mutex_exit(&vq->vq_lock); |
| zio_vdev_io_bypass(zio); |
| zio_execute(zio); |
| mutex_enter(&vq->vq_lock); |
| goto again; |
| } |
| |
| vdev_queue_pending_add(vq, zio); |
| vq->vq_last_offset = zio->io_offset + zio->io_size; |
| |
| return (zio); |
| } |
| |
| zio_t * |
| vdev_queue_io(zio_t *zio) |
| { |
| vdev_queue_t *vq = &zio->io_vd->vdev_queue; |
| zio_t *nio; |
| |
| if (zio->io_flags & ZIO_FLAG_DONT_QUEUE) |
| return (zio); |
| |
| /* |
| * Children i/os inherent their parent's priority, which might |
| * not match the child's i/o type. Fix it up here. |
| */ |
| if (zio->io_type == ZIO_TYPE_READ) { |
| ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); |
| |
| if (zio->io_priority != ZIO_PRIORITY_SYNC_READ && |
| zio->io_priority != ZIO_PRIORITY_ASYNC_READ && |
| zio->io_priority != ZIO_PRIORITY_SCRUB && |
| zio->io_priority != ZIO_PRIORITY_REMOVAL && |
| zio->io_priority != ZIO_PRIORITY_INITIALIZING) { |
| zio->io_priority = ZIO_PRIORITY_ASYNC_READ; |
| } |
| } else if (zio->io_type == ZIO_TYPE_WRITE) { |
| ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); |
| |
| if (zio->io_priority != ZIO_PRIORITY_SYNC_WRITE && |
| zio->io_priority != ZIO_PRIORITY_ASYNC_WRITE && |
| zio->io_priority != ZIO_PRIORITY_REMOVAL && |
| zio->io_priority != ZIO_PRIORITY_INITIALIZING) { |
| zio->io_priority = ZIO_PRIORITY_ASYNC_WRITE; |
| } |
| } else { |
| ASSERT(zio->io_type == ZIO_TYPE_TRIM); |
| ASSERT(zio->io_priority == ZIO_PRIORITY_TRIM); |
| } |
| |
| zio->io_flags |= ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE; |
| |
| mutex_enter(&vq->vq_lock); |
| zio->io_timestamp = gethrtime(); |
| vdev_queue_io_add(vq, zio); |
| nio = vdev_queue_io_to_issue(vq); |
| mutex_exit(&vq->vq_lock); |
| |
| if (nio == NULL) |
| return (NULL); |
| |
| if (nio->io_done == vdev_queue_agg_io_done) { |
| zio_nowait(nio); |
| return (NULL); |
| } |
| |
| return (nio); |
| } |
| |
| void |
| vdev_queue_io_done(zio_t *zio) |
| { |
| vdev_queue_t *vq = &zio->io_vd->vdev_queue; |
| zio_t *nio; |
| |
| mutex_enter(&vq->vq_lock); |
| |
| vdev_queue_pending_remove(vq, zio); |
| |
| zio->io_delta = gethrtime() - zio->io_timestamp; |
| vq->vq_io_complete_ts = gethrtime(); |
| vq->vq_io_delta_ts = vq->vq_io_complete_ts - zio->io_timestamp; |
| |
| while ((nio = vdev_queue_io_to_issue(vq)) != NULL) { |
| mutex_exit(&vq->vq_lock); |
| if (nio->io_done == vdev_queue_agg_io_done) { |
| zio_nowait(nio); |
| } else { |
| zio_vdev_io_reissue(nio); |
| zio_execute(nio); |
| } |
| mutex_enter(&vq->vq_lock); |
| } |
| |
| mutex_exit(&vq->vq_lock); |
| } |
| |
| void |
| vdev_queue_change_io_priority(zio_t *zio, zio_priority_t priority) |
| { |
| vdev_queue_t *vq = &zio->io_vd->vdev_queue; |
| avl_tree_t *tree; |
| |
| /* |
| * ZIO_PRIORITY_NOW is used by the vdev cache code and the aggregate zio |
| * code to issue IOs without adding them to the vdev queue. In this |
| * case, the zio is already going to be issued as quickly as possible |
| * and so it doesn't need any reprioritization to help. |
| */ |
| if (zio->io_priority == ZIO_PRIORITY_NOW) |
| return; |
| |
| ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); |
| ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); |
| |
| if (zio->io_type == ZIO_TYPE_READ) { |
| if (priority != ZIO_PRIORITY_SYNC_READ && |
| priority != ZIO_PRIORITY_ASYNC_READ && |
| priority != ZIO_PRIORITY_SCRUB) |
| priority = ZIO_PRIORITY_ASYNC_READ; |
| } else { |
| ASSERT(zio->io_type == ZIO_TYPE_WRITE); |
| if (priority != ZIO_PRIORITY_SYNC_WRITE && |
| priority != ZIO_PRIORITY_ASYNC_WRITE) |
| priority = ZIO_PRIORITY_ASYNC_WRITE; |
| } |
| |
| mutex_enter(&vq->vq_lock); |
| |
| /* |
| * If the zio is in none of the queues we can simply change |
| * the priority. If the zio is waiting to be submitted we must |
| * remove it from the queue and re-insert it with the new priority. |
| * Otherwise, the zio is currently active and we cannot change its |
| * priority. |
| */ |
| tree = vdev_queue_class_tree(vq, zio->io_priority); |
| if (avl_find(tree, zio, NULL) == zio) { |
| avl_remove(vdev_queue_class_tree(vq, zio->io_priority), zio); |
| zio->io_priority = priority; |
| avl_add(vdev_queue_class_tree(vq, zio->io_priority), zio); |
| } else if (avl_find(&vq->vq_active_tree, zio, NULL) != zio) { |
| zio->io_priority = priority; |
| } |
| |
| mutex_exit(&vq->vq_lock); |
| } |
| |
| /* |
| * As these two methods are only used for load calculations we're not |
| * concerned if we get an incorrect value on 32bit platforms due to lack of |
| * vq_lock mutex use here, instead we prefer to keep it lock free for |
| * performance. |
| */ |
| int |
| vdev_queue_length(vdev_t *vd) |
| { |
| return (avl_numnodes(&vd->vdev_queue.vq_active_tree)); |
| } |
| |
| uint64_t |
| vdev_queue_last_offset(vdev_t *vd) |
| { |
| return (vd->vdev_queue.vq_last_offset); |
| } |
| |
| #if defined(_KERNEL) |
| module_param(zfs_vdev_aggregation_limit, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_aggregation_limit, "Max vdev I/O aggregation size"); |
| |
| module_param(zfs_vdev_aggregation_limit_non_rotating, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_aggregation_limit_non_rotating, |
| "Max vdev I/O aggregation size for non-rotating media"); |
| |
| module_param(zfs_vdev_aggregate_trim, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_aggregate_trim, "Allow TRIM I/O to be aggregated"); |
| |
| module_param(zfs_vdev_read_gap_limit, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_read_gap_limit, "Aggregate read I/O over gap"); |
| |
| module_param(zfs_vdev_write_gap_limit, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_write_gap_limit, "Aggregate write I/O over gap"); |
| |
| module_param(zfs_vdev_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_max_active, "Maximum number of active I/Os per vdev"); |
| |
| module_param(zfs_vdev_async_write_active_max_dirty_percent, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_async_write_active_max_dirty_percent, |
| "Async write concurrency max threshold"); |
| |
| module_param(zfs_vdev_async_write_active_min_dirty_percent, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_async_write_active_min_dirty_percent, |
| "Async write concurrency min threshold"); |
| |
| module_param(zfs_vdev_async_read_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_async_read_max_active, |
| "Max active async read I/Os per vdev"); |
| |
| module_param(zfs_vdev_async_read_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_async_read_min_active, |
| "Min active async read I/Os per vdev"); |
| |
| module_param(zfs_vdev_async_write_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_async_write_max_active, |
| "Max active async write I/Os per vdev"); |
| |
| module_param(zfs_vdev_async_write_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_async_write_min_active, |
| "Min active async write I/Os per vdev"); |
| |
| module_param(zfs_vdev_initializing_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_initializing_max_active, |
| "Max active initializing I/Os per vdev"); |
| |
| module_param(zfs_vdev_initializing_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_initializing_min_active, |
| "Min active initializing I/Os per vdev"); |
| |
| module_param(zfs_vdev_removal_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_removal_max_active, |
| "Max active removal I/Os per vdev"); |
| |
| module_param(zfs_vdev_removal_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_removal_min_active, |
| "Min active removal I/Os per vdev"); |
| |
| module_param(zfs_vdev_scrub_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_scrub_max_active, |
| "Max active scrub I/Os per vdev"); |
| |
| module_param(zfs_vdev_scrub_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_scrub_min_active, |
| "Min active scrub I/Os per vdev"); |
| |
| module_param(zfs_vdev_sync_read_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_sync_read_max_active, |
| "Max active sync read I/Os per vdev"); |
| |
| module_param(zfs_vdev_sync_read_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_sync_read_min_active, |
| "Min active sync read I/Os per vdev"); |
| |
| module_param(zfs_vdev_sync_write_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_sync_write_max_active, |
| "Max active sync write I/Os per vdev"); |
| |
| module_param(zfs_vdev_sync_write_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_sync_write_min_active, |
| "Min active sync write I/Os per vdev"); |
| |
| module_param(zfs_vdev_trim_max_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_trim_max_active, |
| "Max active trim/discard I/Os per vdev"); |
| |
| module_param(zfs_vdev_trim_min_active, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_trim_min_active, |
| "Min active trim/discard I/Os per vdev"); |
| |
| module_param(zfs_vdev_queue_depth_pct, int, 0644); |
| MODULE_PARM_DESC(zfs_vdev_queue_depth_pct, |
| "Queue depth percentage for each top-level vdev"); |
| #endif |