diff --git a/include/sys/arc_impl.h b/include/sys/arc_impl.h index 9aca8e1d24..c6363f2ab7 100644 --- a/include/sys/arc_impl.h +++ b/include/sys/arc_impl.h @@ -70,7 +70,7 @@ typedef struct arc_state { /* * list of evictable buffers */ - multilist_t arcs_list[ARC_BUFC_NUMTYPES]; + multilist_t *arcs_list[ARC_BUFC_NUMTYPES]; /* * total amount of evictable data in this state */ diff --git a/include/sys/dmu_objset.h b/include/sys/dmu_objset.h index f03f0779d9..636b0e2493 100644 --- a/include/sys/dmu_objset.h +++ b/include/sys/dmu_objset.h @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2012, 2016 by Delphix. All rights reserved. + * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. */ @@ -113,7 +113,7 @@ struct objset { /* no lock needed: */ struct dmu_tx *os_synctx; /* XXX sketchy */ zil_header_t os_zil_header; - list_t os_synced_dnodes; + multilist_t *os_synced_dnodes; uint64_t os_flags; uint64_t os_freed_dnodes; boolean_t os_rescan_dnodes; @@ -124,11 +124,13 @@ struct objset { /* Protected by os_lock */ kmutex_t os_lock; - list_t os_dirty_dnodes[TXG_SIZE]; - list_t os_free_dnodes[TXG_SIZE]; + multilist_t *os_dirty_dnodes[TXG_SIZE]; list_t os_dnodes; list_t os_downgraded_dbufs; + /* Protects changes to DMU_{USER,GROUP}USED_OBJECT */ + kmutex_t os_userused_lock; + /* stuff we store for the user */ kmutex_t os_user_ptr_lock; void *os_user_ptr; diff --git a/include/sys/dnode.h b/include/sys/dnode.h index a6a9ef8222..d32855dcdf 100644 --- a/include/sys/dnode.h +++ b/include/sys/dnode.h @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2012, 2016 by Delphix. All rights reserved. + * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. */ @@ -35,6 +35,7 @@ #include #include #include +#include #ifdef __cplusplus extern "C" { @@ -243,7 +244,7 @@ struct dnode { uint32_t dn_dbufs_count; /* count of dn_dbufs */ /* protected by os_lock: */ - list_node_t dn_dirty_link[TXG_SIZE]; /* next on dataset's dirty */ + multilist_node_t dn_dirty_link[TXG_SIZE]; /* next on dataset's dirty */ /* protected by dn_mtx: */ kmutex_t dn_mtx; diff --git a/include/sys/dsl_pool.h b/include/sys/dsl_pool.h index b509d312b6..674dd25b56 100644 --- a/include/sys/dsl_pool.h +++ b/include/sys/dsl_pool.h @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2013 by Delphix. All rights reserved. + * Copyright (c) 2013, 2017 by Delphix. All rights reserved. * Copyright 2016 Nexenta Systems, Inc. All rights reserved. */ @@ -124,6 +124,7 @@ typedef struct dsl_pool { txg_list_t dp_dirty_zilogs; txg_list_t dp_dirty_dirs; txg_list_t dp_sync_tasks; + taskq_t *dp_sync_taskq; /* * Protects administrative changes (properties, namespace) diff --git a/include/sys/multilist.h b/include/sys/multilist.h index 9b19d016d9..4395406859 100644 --- a/include/sys/multilist.h +++ b/include/sys/multilist.h @@ -72,8 +72,7 @@ struct multilist { }; void multilist_destroy(multilist_t *); -void multilist_create(multilist_t *, size_t, size_t, - multilist_sublist_index_func_t *); +multilist_t *multilist_create(size_t, size_t, multilist_sublist_index_func_t *); void multilist_insert(multilist_t *, void *); void multilist_remove(multilist_t *, void *); @@ -83,6 +82,7 @@ unsigned int multilist_get_num_sublists(multilist_t *); unsigned int multilist_get_random_index(multilist_t *); multilist_sublist_t *multilist_sublist_lock(multilist_t *, unsigned int); +multilist_sublist_t *multilist_sublist_lock_obj(multilist_t *, void *); void multilist_sublist_unlock(multilist_sublist_t *); void multilist_sublist_insert_head(multilist_sublist_t *, void *); diff --git a/include/sys/zio.h b/include/sys/zio.h index 1f8708e5a0..dc6c46814e 100644 --- a/include/sys/zio.h +++ b/include/sys/zio.h @@ -22,7 +22,7 @@ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright 2011 Nexenta Systems, Inc. All rights reserved. - * Copyright (c) 2012, 2016 by Delphix. All rights reserved. + * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. */ @@ -454,7 +454,7 @@ struct zio { taskq_ent_t io_tqent; }; -extern int zio_timestamp_compare(const void *, const void *); +extern int zio_bookmark_compare(const void *, const void *); extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, void *private, enum zio_flag flags); diff --git a/module/zfs/arc.c b/module/zfs/arc.c index 5764a63a4b..9e5712c7b8 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -1927,7 +1927,7 @@ add_reference(arc_buf_hdr_t *hdr, void *tag) (state != arc_anon)) { /* We don't use the L2-only state list. */ if (state != arc_l2c_only) { - multilist_remove(&state->arcs_list[arc_buf_type(hdr)], + multilist_remove(state->arcs_list[arc_buf_type(hdr)], hdr); arc_evictable_space_decrement(hdr, state); } @@ -1957,7 +1957,7 @@ remove_reference(arc_buf_hdr_t *hdr, kmutex_t *hash_lock, void *tag) */ if (((cnt = refcount_remove(&hdr->b_l1hdr.b_refcnt, tag)) == 0) && (state != arc_anon)) { - multilist_insert(&state->arcs_list[arc_buf_type(hdr)], hdr); + multilist_insert(state->arcs_list[arc_buf_type(hdr)], hdr); ASSERT3U(hdr->b_l1hdr.b_bufcnt, >, 0); arc_evictable_space_increment(hdr, state); } @@ -2059,7 +2059,7 @@ arc_change_state(arc_state_t *new_state, arc_buf_hdr_t *hdr, if (refcnt == 0) { if (old_state != arc_anon && old_state != arc_l2c_only) { ASSERT(HDR_HAS_L1HDR(hdr)); - multilist_remove(&old_state->arcs_list[buftype], hdr); + multilist_remove(old_state->arcs_list[buftype], hdr); if (GHOST_STATE(old_state)) { ASSERT0(bufcnt); @@ -2076,7 +2076,7 @@ arc_change_state(arc_state_t *new_state, arc_buf_hdr_t *hdr, * beforehand. */ ASSERT(HDR_HAS_L1HDR(hdr)); - multilist_insert(&new_state->arcs_list[buftype], hdr); + multilist_insert(new_state->arcs_list[buftype], hdr); if (GHOST_STATE(new_state)) { ASSERT0(bufcnt); @@ -2204,8 +2204,8 @@ arc_change_state(arc_state_t *new_state, arc_buf_hdr_t *hdr, * L2 headers should never be on the L2 state list since they don't * have L1 headers allocated. */ - ASSERT(multilist_is_empty(&arc_l2c_only->arcs_list[ARC_BUFC_DATA]) && - multilist_is_empty(&arc_l2c_only->arcs_list[ARC_BUFC_METADATA])); + ASSERT(multilist_is_empty(arc_l2c_only->arcs_list[ARC_BUFC_DATA]) && + multilist_is_empty(arc_l2c_only->arcs_list[ARC_BUFC_METADATA])); } void @@ -3302,7 +3302,7 @@ arc_evict_state(arc_state_t *state, uint64_t spa, int64_t bytes, arc_buf_contents_t type) { uint64_t total_evicted = 0; - multilist_t *ml = &state->arcs_list[type]; + multilist_t *ml = state->arcs_list[type]; int num_sublists; arc_buf_hdr_t **markers; int i; @@ -3681,8 +3681,8 @@ arc_adjust_meta(void) static arc_buf_contents_t arc_adjust_type(arc_state_t *state) { - multilist_t *data_ml = &state->arcs_list[ARC_BUFC_DATA]; - multilist_t *meta_ml = &state->arcs_list[ARC_BUFC_METADATA]; + multilist_t *data_ml = state->arcs_list[ARC_BUFC_DATA]; + multilist_t *meta_ml = state->arcs_list[ARC_BUFC_METADATA]; int data_idx = multilist_get_random_index(data_ml); int meta_idx = multilist_get_random_index(meta_ml); multilist_sublist_t *data_mls; @@ -6281,44 +6281,44 @@ arc_state_init(void) arc_mfu_ghost = &ARC_mfu_ghost; arc_l2c_only = &ARC_l2c_only; - multilist_create(&arc_mru->arcs_list[ARC_BUFC_METADATA], - sizeof (arc_buf_hdr_t), + arc_mru->arcs_list[ARC_BUFC_METADATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_mru->arcs_list[ARC_BUFC_DATA], - sizeof (arc_buf_hdr_t), + arc_mru->arcs_list[ARC_BUFC_DATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_mru_ghost->arcs_list[ARC_BUFC_METADATA], - sizeof (arc_buf_hdr_t), + arc_mru_ghost->arcs_list[ARC_BUFC_METADATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_mru_ghost->arcs_list[ARC_BUFC_DATA], - sizeof (arc_buf_hdr_t), + arc_mru_ghost->arcs_list[ARC_BUFC_DATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_mfu->arcs_list[ARC_BUFC_METADATA], - sizeof (arc_buf_hdr_t), + arc_mfu->arcs_list[ARC_BUFC_METADATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_mfu->arcs_list[ARC_BUFC_DATA], - sizeof (arc_buf_hdr_t), + arc_mfu->arcs_list[ARC_BUFC_DATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA], - sizeof (arc_buf_hdr_t), + arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_mfu_ghost->arcs_list[ARC_BUFC_DATA], - sizeof (arc_buf_hdr_t), + arc_mfu_ghost->arcs_list[ARC_BUFC_DATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_l2c_only->arcs_list[ARC_BUFC_METADATA], - sizeof (arc_buf_hdr_t), + arc_l2c_only->arcs_list[ARC_BUFC_METADATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); - multilist_create(&arc_l2c_only->arcs_list[ARC_BUFC_DATA], - sizeof (arc_buf_hdr_t), + arc_l2c_only->arcs_list[ARC_BUFC_DATA] = + multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); @@ -6373,16 +6373,16 @@ arc_state_fini(void) refcount_destroy(&arc_mfu_ghost->arcs_size); refcount_destroy(&arc_l2c_only->arcs_size); - multilist_destroy(&arc_mru->arcs_list[ARC_BUFC_METADATA]); - multilist_destroy(&arc_mru_ghost->arcs_list[ARC_BUFC_METADATA]); - multilist_destroy(&arc_mfu->arcs_list[ARC_BUFC_METADATA]); - multilist_destroy(&arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA]); - multilist_destroy(&arc_mru->arcs_list[ARC_BUFC_DATA]); - multilist_destroy(&arc_mru_ghost->arcs_list[ARC_BUFC_DATA]); - multilist_destroy(&arc_mfu->arcs_list[ARC_BUFC_DATA]); - multilist_destroy(&arc_mfu_ghost->arcs_list[ARC_BUFC_DATA]); - multilist_destroy(&arc_l2c_only->arcs_list[ARC_BUFC_METADATA]); - multilist_destroy(&arc_l2c_only->arcs_list[ARC_BUFC_DATA]); + multilist_destroy(arc_mru->arcs_list[ARC_BUFC_METADATA]); + multilist_destroy(arc_mru_ghost->arcs_list[ARC_BUFC_METADATA]); + multilist_destroy(arc_mfu->arcs_list[ARC_BUFC_METADATA]); + multilist_destroy(arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA]); + multilist_destroy(arc_mru->arcs_list[ARC_BUFC_DATA]); + multilist_destroy(arc_mru_ghost->arcs_list[ARC_BUFC_DATA]); + multilist_destroy(arc_mfu->arcs_list[ARC_BUFC_DATA]); + multilist_destroy(arc_mfu_ghost->arcs_list[ARC_BUFC_DATA]); + multilist_destroy(arc_l2c_only->arcs_list[ARC_BUFC_METADATA]); + multilist_destroy(arc_l2c_only->arcs_list[ARC_BUFC_DATA]); } uint64_t @@ -7065,16 +7065,16 @@ l2arc_sublist_lock(int list_num) switch (list_num) { case 0: - ml = &arc_mfu->arcs_list[ARC_BUFC_METADATA]; + ml = arc_mfu->arcs_list[ARC_BUFC_METADATA]; break; case 1: - ml = &arc_mru->arcs_list[ARC_BUFC_METADATA]; + ml = arc_mru->arcs_list[ARC_BUFC_METADATA]; break; case 2: - ml = &arc_mfu->arcs_list[ARC_BUFC_DATA]; + ml = arc_mfu->arcs_list[ARC_BUFC_DATA]; break; case 3: - ml = &arc_mru->arcs_list[ARC_BUFC_DATA]; + ml = arc_mru->arcs_list[ARC_BUFC_DATA]; break; default: return (NULL); diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c index f11a11ff1e..ce99fd54c1 100644 --- a/module/zfs/dbuf.c +++ b/module/zfs/dbuf.c @@ -21,7 +21,7 @@ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright 2011 Nexenta Systems, Inc. All rights reserved. - * Copyright (c) 2012, 2015 by Delphix. All rights reserved. + * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. */ @@ -104,7 +104,7 @@ static boolean_t dbuf_evict_thread_exit; * Dbufs that are aged out of the cache will be immediately destroyed and * become eligible for arc eviction. */ -static multilist_t dbuf_cache; +static multilist_t *dbuf_cache; static refcount_t dbuf_cache_size; unsigned long dbuf_cache_max_bytes = 100 * 1024 * 1024; @@ -491,8 +491,8 @@ dbuf_cache_above_lowater(void) static void dbuf_evict_one(void) { - int idx = multilist_get_random_index(&dbuf_cache); - multilist_sublist_t *mls = multilist_sublist_lock(&dbuf_cache, idx); + int idx = multilist_get_random_index(dbuf_cache); + multilist_sublist_t *mls = multilist_sublist_lock(dbuf_cache, idx); dmu_buf_impl_t *db; ASSERT(!MUTEX_HELD(&dbuf_evict_lock)); @@ -671,7 +671,7 @@ retry: */ dbu_evict_taskq = taskq_create("dbu_evict", 1, defclsyspri, 0, 0, 0); - multilist_create(&dbuf_cache, sizeof (dmu_buf_impl_t), + dbuf_cache = multilist_create(sizeof (dmu_buf_impl_t), offsetof(dmu_buf_impl_t, db_cache_link), dbuf_cache_multilist_index_func); refcount_create(&dbuf_cache_size); @@ -719,7 +719,7 @@ dbuf_fini(void) cv_destroy(&dbuf_evict_cv); refcount_destroy(&dbuf_cache_size); - multilist_destroy(&dbuf_cache); + multilist_destroy(dbuf_cache); } /* @@ -2120,7 +2120,7 @@ dbuf_destroy(dmu_buf_impl_t *db) dbuf_clear_data(db); if (multilist_link_active(&db->db_cache_link)) { - multilist_remove(&dbuf_cache, db); + multilist_remove(dbuf_cache, db); (void) refcount_remove_many(&dbuf_cache_size, db->db.db_size, db); } @@ -2690,7 +2690,7 @@ __dbuf_hold_impl(struct dbuf_hold_impl_data *dh) if (multilist_link_active(&dh->dh_db->db_cache_link)) { ASSERT(refcount_is_zero(&dh->dh_db->db_holds)); - multilist_remove(&dbuf_cache, dh->dh_db); + multilist_remove(dbuf_cache, dh->dh_db); (void) refcount_remove_many(&dbuf_cache_size, dh->dh_db->db.db_size, dh->dh_db); } @@ -2962,7 +2962,7 @@ dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag) db->db_pending_evict) { dbuf_destroy(db); } else if (!multilist_link_active(&db->db_cache_link)) { - multilist_insert(&dbuf_cache, db); + multilist_insert(dbuf_cache, db); (void) refcount_add_many(&dbuf_cache_size, db->db.db_size, db); mutex_exit(&db->db_mtx); diff --git a/module/zfs/dmu_objset.c b/module/zfs/dmu_objset.c index 21b68f9f75..43de05c502 100644 --- a/module/zfs/dmu_objset.c +++ b/module/zfs/dmu_objset.c @@ -21,7 +21,7 @@ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2012, 2016 by Delphix. All rights reserved. + * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2013, Joyent, Inc. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. @@ -343,6 +343,38 @@ dmu_objset_byteswap(void *buf, size_t size) } } +/* + * The hash is a CRC-based hash of the objset_t pointer and the object number. + */ +static uint64_t +dnode_hash(const objset_t *os, uint64_t obj) +{ + uintptr_t osv = (uintptr_t)os; + uint64_t crc = -1ULL; + + ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY); + /* + * The low 6 bits of the pointer don't have much entropy, because + * the objset_t is larger than 2^6 bytes long. + */ + crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (osv >> 6)) & 0xFF]; + crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 0)) & 0xFF]; + crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 8)) & 0xFF]; + crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 16)) & 0xFF]; + + crc ^= (osv>>14) ^ (obj>>24); + + return (crc); +} + +unsigned int +dnode_multilist_index_func(multilist_t *ml, void *obj) +{ + dnode_t *dn = obj; + return (dnode_hash(dn->dn_objset, dn->dn_object) % + multilist_get_num_sublists(ml)); +} + int dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp, objset_t **osp) @@ -500,10 +532,9 @@ dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp, os->os_zil = zil_alloc(os, &os->os_zil_header); for (i = 0; i < TXG_SIZE; i++) { - list_create(&os->os_dirty_dnodes[i], sizeof (dnode_t), - offsetof(dnode_t, dn_dirty_link[i])); - list_create(&os->os_free_dnodes[i], sizeof (dnode_t), - offsetof(dnode_t, dn_dirty_link[i])); + os->os_dirty_dnodes[i] = multilist_create(sizeof (dnode_t), + offsetof(dnode_t, dn_dirty_link[i]), + dnode_multilist_index_func); } list_create(&os->os_dnodes, sizeof (dnode_t), offsetof(dnode_t, dn_link)); @@ -513,6 +544,7 @@ dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp, list_link_init(&os->os_evicting_node); mutex_init(&os->os_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&os->os_userused_lock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&os->os_obj_lock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&os->os_user_ptr_lock, NULL, MUTEX_DEFAULT, NULL); @@ -811,8 +843,12 @@ dmu_objset_evict_done(objset_t *os) rw_exit(&os_lock); mutex_destroy(&os->os_lock); + mutex_destroy(&os->os_userused_lock); mutex_destroy(&os->os_obj_lock); mutex_destroy(&os->os_user_ptr_lock); + for (int i = 0; i < TXG_SIZE; i++) { + multilist_destroy(os->os_dirty_dnodes[i]); + } spa_evicting_os_deregister(os->os_spa, os); kmem_free(os, sizeof (objset_t)); } @@ -1153,11 +1189,11 @@ dmu_objset_upgrade_stop(objset_t *os) } static void -dmu_objset_sync_dnodes(list_t *list, list_t *newlist, dmu_tx_t *tx) +dmu_objset_sync_dnodes(multilist_sublist_t *list, dmu_tx_t *tx) { dnode_t *dn; - while ((dn = list_head(list))) { + while ((dn = multilist_sublist_head(list)) != NULL) { ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT); ASSERT(dn->dn_dbuf->db_data_pending); /* @@ -1168,11 +1204,12 @@ dmu_objset_sync_dnodes(list_t *list, list_t *newlist, dmu_tx_t *tx) ASSERT(dn->dn_zio); ASSERT3U(dn->dn_nlevels, <=, DN_MAX_LEVELS); - list_remove(list, dn); + multilist_sublist_remove(list, dn); - if (newlist) { + multilist_t *newlist = dn->dn_objset->os_synced_dnodes; + if (newlist != NULL) { (void) dnode_add_ref(dn, newlist); - list_insert_tail(newlist, dn); + multilist_insert(newlist, dn); } dnode_sync(dn, tx); @@ -1229,6 +1266,29 @@ dmu_objset_write_done(zio_t *zio, arc_buf_t *abuf, void *arg) kmem_free(bp, sizeof (*bp)); } +typedef struct sync_dnodes_arg { + multilist_t *sda_list; + int sda_sublist_idx; + multilist_t *sda_newlist; + dmu_tx_t *sda_tx; +} sync_dnodes_arg_t; + +static void +sync_dnodes_task(void *arg) +{ + sync_dnodes_arg_t *sda = arg; + + multilist_sublist_t *ms = + multilist_sublist_lock(sda->sda_list, sda->sda_sublist_idx); + + dmu_objset_sync_dnodes(ms, sda->sda_tx); + + multilist_sublist_unlock(ms); + + kmem_free(sda, sizeof (*sda)); +} + + /* called from dsl */ void dmu_objset_sync(objset_t *os, zio_t *pio, dmu_tx_t *tx) @@ -1238,7 +1298,6 @@ dmu_objset_sync(objset_t *os, zio_t *pio, dmu_tx_t *tx) zio_prop_t zp; zio_t *zio; list_t *list; - list_t *newlist = NULL; dbuf_dirty_record_t *dr; blkptr_t *blkptr_copy = kmem_alloc(sizeof (*os->os_rootbp), KM_SLEEP); *blkptr_copy = *os->os_rootbp; @@ -1292,20 +1351,36 @@ dmu_objset_sync(objset_t *os, zio_t *pio, dmu_tx_t *tx) txgoff = tx->tx_txg & TXG_MASK; if (dmu_objset_userused_enabled(os)) { - newlist = &os->os_synced_dnodes; /* * We must create the list here because it uses the - * dn_dirty_link[] of this txg. + * dn_dirty_link[] of this txg. But it may already + * exist because we call dsl_dataset_sync() twice per txg. */ - list_create(newlist, sizeof (dnode_t), - offsetof(dnode_t, dn_dirty_link[txgoff])); + if (os->os_synced_dnodes == NULL) { + os->os_synced_dnodes = + multilist_create(sizeof (dnode_t), + offsetof(dnode_t, dn_dirty_link[txgoff]), + dnode_multilist_index_func); + } else { + ASSERT3U(os->os_synced_dnodes->ml_offset, ==, + offsetof(dnode_t, dn_dirty_link[txgoff])); + } } - dmu_objset_sync_dnodes(&os->os_free_dnodes[txgoff], newlist, tx); - dmu_objset_sync_dnodes(&os->os_dirty_dnodes[txgoff], newlist, tx); + for (int i = 0; + i < multilist_get_num_sublists(os->os_dirty_dnodes[txgoff]); i++) { + sync_dnodes_arg_t *sda = kmem_alloc(sizeof (*sda), KM_SLEEP); + sda->sda_list = os->os_dirty_dnodes[txgoff]; + sda->sda_sublist_idx = i; + sda->sda_tx = tx; + (void) taskq_dispatch(dmu_objset_pool(os)->dp_sync_taskq, + sync_dnodes_task, sda, 0); + /* callback frees sda */ + } + taskq_wait(dmu_objset_pool(os)->dp_sync_taskq); list = &DMU_META_DNODE(os)->dn_dirty_records[txgoff]; - while ((dr = list_head(list))) { + while ((dr = list_head(list)) != NULL) { ASSERT0(dr->dr_dbuf->db_level); list_remove(list, dr); if (dr->dr_zio) @@ -1329,8 +1404,7 @@ dmu_objset_sync(objset_t *os, zio_t *pio, dmu_tx_t *tx) boolean_t dmu_objset_is_dirty(objset_t *os, uint64_t txg) { - return (!list_is_empty(&os->os_dirty_dnodes[txg & TXG_MASK]) || - !list_is_empty(&os->os_free_dnodes[txg & TXG_MASK])); + return (!multilist_is_empty(os->os_dirty_dnodes[txg & TXG_MASK])); } static objset_used_cb_t *used_cbs[DMU_OST_NUMTYPES]; @@ -1395,8 +1469,15 @@ do_userquota_cacheflush(objset_t *os, userquota_cache_t *cache, dmu_tx_t *tx) cookie = NULL; while ((uqn = avl_destroy_nodes(&cache->uqc_user_deltas, &cookie)) != NULL) { + /* + * os_userused_lock protects against concurrent calls to + * zap_increment_int(). It's needed because zap_increment_int() + * is not thread-safe (i.e. not atomic). + */ + mutex_enter(&os->os_userused_lock); VERIFY0(zap_increment(os, DMU_USERUSED_OBJECT, uqn->uqn_id, uqn->uqn_delta, tx)); + mutex_exit(&os->os_userused_lock); kmem_free(uqn, sizeof (*uqn)); } avl_destroy(&cache->uqc_user_deltas); @@ -1404,8 +1485,10 @@ do_userquota_cacheflush(objset_t *os, userquota_cache_t *cache, dmu_tx_t *tx) cookie = NULL; while ((uqn = avl_destroy_nodes(&cache->uqc_group_deltas, &cookie)) != NULL) { + mutex_enter(&os->os_userused_lock); VERIFY0(zap_increment(os, DMU_GROUPUSED_OBJECT, uqn->uqn_id, uqn->uqn_delta, tx)); + mutex_exit(&os->os_userused_lock); kmem_free(uqn, sizeof (*uqn)); } avl_destroy(&cache->uqc_group_deltas); @@ -1469,35 +1552,38 @@ do_userobjquota_update(userquota_cache_t *cache, uint64_t flags, } } -void -dmu_objset_do_userquota_updates(objset_t *os, dmu_tx_t *tx) +typedef struct userquota_updates_arg { + objset_t *uua_os; + int uua_sublist_idx; + dmu_tx_t *uua_tx; +} userquota_updates_arg_t; + +static void +userquota_updates_task(void *arg) { + userquota_updates_arg_t *uua = arg; + objset_t *os = uua->uua_os; + dmu_tx_t *tx = uua->uua_tx; dnode_t *dn; - list_t *list = &os->os_synced_dnodes; userquota_cache_t cache = { { 0 } }; - ASSERT(list_head(list) == NULL || dmu_objset_userused_enabled(os)); + multilist_sublist_t *list = + multilist_sublist_lock(os->os_synced_dnodes, uua->uua_sublist_idx); + ASSERT(multilist_sublist_head(list) == NULL || + dmu_objset_userused_enabled(os)); avl_create(&cache.uqc_user_deltas, userquota_compare, sizeof (userquota_node_t), offsetof(userquota_node_t, uqn_node)); avl_create(&cache.uqc_group_deltas, userquota_compare, sizeof (userquota_node_t), offsetof(userquota_node_t, uqn_node)); - while ((dn = list_head(list))) { + while ((dn = multilist_sublist_head(list)) != NULL) { int flags; ASSERT(!DMU_OBJECT_IS_SPECIAL(dn->dn_object)); ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE || dn->dn_phys->dn_flags & DNODE_FLAG_USERUSED_ACCOUNTED); - /* Allocate the user/groupused objects if necessary. */ - if (DMU_USERUSED_DNODE(os)->dn_type == DMU_OT_NONE) { - VERIFY0(zap_create_claim(os, DMU_USERUSED_OBJECT, - DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx)); - VERIFY0(zap_create_claim(os, DMU_GROUPUSED_OBJECT, - DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx)); - } - flags = dn->dn_id_flags; ASSERT(flags); if (flags & DN_ID_OLD_EXIST) { @@ -1530,10 +1616,42 @@ dmu_objset_do_userquota_updates(objset_t *os, dmu_tx_t *tx) dn->dn_id_flags &= ~(DN_ID_NEW_EXIST); mutex_exit(&dn->dn_mtx); - list_remove(list, dn); - dnode_rele(dn, list); + multilist_sublist_remove(list, dn); + dnode_rele(dn, os->os_synced_dnodes); } do_userquota_cacheflush(os, &cache, tx); + multilist_sublist_unlock(list); + kmem_free(uua, sizeof (*uua)); +} + +void +dmu_objset_do_userquota_updates(objset_t *os, dmu_tx_t *tx) +{ + if (!dmu_objset_userused_enabled(os)) + return; + + /* Allocate the user/groupused objects if necessary. */ + if (DMU_USERUSED_DNODE(os)->dn_type == DMU_OT_NONE) { + VERIFY0(zap_create_claim(os, + DMU_USERUSED_OBJECT, + DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx)); + VERIFY0(zap_create_claim(os, + DMU_GROUPUSED_OBJECT, + DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx)); + } + + for (int i = 0; + i < multilist_get_num_sublists(os->os_synced_dnodes); i++) { + userquota_updates_arg_t *uua = + kmem_alloc(sizeof (*uua), KM_SLEEP); + uua->uua_os = os; + uua->uua_sublist_idx = i; + uua->uua_tx = tx; + /* note: caller does taskq_wait() */ + (void) taskq_dispatch(dmu_objset_pool(os)->dp_sync_taskq, + userquota_updates_task, uua, 0); + /* callback frees uua */ + } } /* diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c index 28ed7de046..fd4acbbaa5 100644 --- a/module/zfs/dnode.c +++ b/module/zfs/dnode.c @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2012, 2016 by Delphix. All rights reserved. + * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. */ @@ -1421,13 +1421,14 @@ dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) */ dmu_objset_userquota_get_ids(dn, B_TRUE, tx); - mutex_enter(&os->os_lock); + multilist_t *dirtylist = os->os_dirty_dnodes[txg & TXG_MASK]; + multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn); /* * If we are already marked dirty, we're done. */ if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { - mutex_exit(&os->os_lock); + multilist_sublist_unlock(mls); return; } @@ -1441,13 +1442,9 @@ dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", dn->dn_object, txg); - if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { - list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); - } else { - list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); - } + multilist_sublist_insert_head(mls, dn); - mutex_exit(&os->os_lock); + multilist_sublist_unlock(mls); /* * The dnode maintains a hold on its containing dbuf as @@ -1468,13 +1465,6 @@ dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) void dnode_free(dnode_t *dn, dmu_tx_t *tx) { - int txgoff = tx->tx_txg & TXG_MASK; - - dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); - - /* we should be the only holder... hopefully */ - /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ - mutex_enter(&dn->dn_mtx); if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { mutex_exit(&dn->dn_mtx); @@ -1483,19 +1473,7 @@ dnode_free(dnode_t *dn, dmu_tx_t *tx) dn->dn_free_txg = tx->tx_txg; mutex_exit(&dn->dn_mtx); - /* - * If the dnode is already dirty, it needs to be moved from - * the dirty list to the free list. - */ - mutex_enter(&dn->dn_objset->os_lock); - if (list_link_active(&dn->dn_dirty_link[txgoff])) { - list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); - list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); - mutex_exit(&dn->dn_objset->os_lock); - } else { - mutex_exit(&dn->dn_objset->os_lock); - dnode_setdirty(dn, tx); - } + dnode_setdirty(dn, tx); } /* diff --git a/module/zfs/dnode_sync.c b/module/zfs/dnode_sync.c index 9f3c6a2c77..742d962bc2 100644 --- a/module/zfs/dnode_sync.c +++ b/module/zfs/dnode_sync.c @@ -21,7 +21,7 @@ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2012, 2016 by Delphix. All rights reserved. + * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. */ diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c index f83da16e52..5fa04e7ba7 100644 --- a/module/zfs/dsl_dataset.c +++ b/module/zfs/dsl_dataset.c @@ -1699,11 +1699,16 @@ deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) void dsl_dataset_sync_done(dsl_dataset_t *ds, dmu_tx_t *tx) { - ASSERTV(objset_t *os = ds->ds_objset); + objset_t *os = ds->ds_objset; bplist_iterate(&ds->ds_pending_deadlist, deadlist_enqueue_cb, &ds->ds_deadlist, tx); + if (os->os_synced_dnodes != NULL) { + multilist_destroy(os->os_synced_dnodes); + os->os_synced_dnodes = NULL; + } + ASSERT(!dmu_objset_is_dirty(os, dmu_tx_get_txg(tx))); dmu_buf_rele(ds->ds_dbuf, ds); diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c index d1aeb8017b..2386484c80 100644 --- a/module/zfs/dsl_pool.c +++ b/module/zfs/dsl_pool.c @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011, 2015 by Delphix. All rights reserved. + * Copyright (c) 2011, 2017 by Delphix. All rights reserved. * Copyright (c) 2013 Steven Hartland. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. * Copyright 2016 Nexenta Systems, Inc. All rights reserved. @@ -132,6 +132,11 @@ unsigned long zfs_delay_scale = 1000 * 1000 * 1000 / 2000; hrtime_t zfs_throttle_delay = MSEC2NSEC(10); hrtime_t zfs_throttle_resolution = MSEC2NSEC(10); +/* + * This determines the number of threads used by the dp_sync_taskq. + */ +int zfs_sync_taskq_batch_pct = 75; + int dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp) { @@ -168,6 +173,10 @@ dsl_pool_open_impl(spa_t *spa, uint64_t txg) txg_list_create(&dp->dp_sync_tasks, offsetof(dsl_sync_task_t, dst_node)); + dp->dp_sync_taskq = taskq_create("dp_sync_taskq", + zfs_sync_taskq_batch_pct, minclsyspri, 1, INT_MAX, + TASKQ_THREADS_CPU_PCT); + mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL); @@ -326,6 +335,8 @@ dsl_pool_close(dsl_pool_t *dp) txg_list_destroy(&dp->dp_sync_tasks); txg_list_destroy(&dp->dp_dirty_dirs); + taskq_destroy(dp->dp_sync_taskq); + /* * We can't set retry to TRUE since we're explicitly specifying * a spa to flush. This is good enough; any missed buffers for @@ -514,12 +525,15 @@ dsl_pool_sync(dsl_pool_t *dp, uint64_t txg) /* * After the data blocks have been written (ensured by the zio_wait() - * above), update the user/group space accounting. + * above), update the user/group space accounting. This happens + * in tasks dispatched to dp_sync_taskq, so wait for them before + * continuing. */ for (ds = list_head(&synced_datasets); ds != NULL; ds = list_next(&synced_datasets, ds)) { dmu_objset_do_userquota_updates(ds->ds_objset, tx); } + taskq_wait(dp->dp_sync_taskq); /* * Sync the datasets again to push out the changes due to @@ -567,8 +581,7 @@ dsl_pool_sync(dsl_pool_t *dp, uint64_t txg) dp->dp_mos_uncompressed_delta = 0; } - if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL || - list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) { + if (!multilist_is_empty(mos->os_dirty_dnodes[txg & TXG_MASK])) { dsl_pool_sync_mos(dp, tx); } @@ -619,7 +632,8 @@ int dsl_pool_sync_context(dsl_pool_t *dp) { return (curthread == dp->dp_tx.tx_sync_thread || - spa_is_initializing(dp->dp_spa)); + spa_is_initializing(dp->dp_spa) || + taskq_member(dp->dp_sync_taskq, curthread)); } uint64_t @@ -1116,5 +1130,9 @@ MODULE_PARM_DESC(zfs_dirty_data_sync, "sync txg when this much dirty data"); module_param(zfs_delay_scale, ulong, 0644); MODULE_PARM_DESC(zfs_delay_scale, "how quickly delay approaches infinity"); + +module_param(zfs_sync_taskq_batch_pct, int, 0644); +MODULE_PARM_DESC(zfs_sync_taskq_batch_pct, + "max percent of CPUs that are used to sync dirty data"); /* END CSTYLED */ #endif diff --git a/module/zfs/multilist.c b/module/zfs/multilist.c index fa927b43ba..40fa1686e1 100644 --- a/module/zfs/multilist.c +++ b/module/zfs/multilist.c @@ -68,18 +68,16 @@ multilist_d2l(multilist_t *ml, void *obj) * requirement, but a general rule of thumb in order to garner the * best multi-threaded performance out of the data structure. */ -static void -multilist_create_impl(multilist_t *ml, size_t size, size_t offset, +static multilist_t * +multilist_create_impl(size_t size, size_t offset, unsigned int num, multilist_sublist_index_func_t *index_func) { - int i; - - ASSERT3P(ml, !=, NULL); ASSERT3U(size, >, 0); ASSERT3U(size, >=, offset + sizeof (multilist_node_t)); ASSERT3U(num, >, 0); ASSERT3P(index_func, !=, NULL); + multilist_t *ml = kmem_alloc(sizeof (*ml), KM_SLEEP); ml->ml_offset = offset; ml->ml_num_sublists = num; ml->ml_index_func = index_func; @@ -89,20 +87,21 @@ multilist_create_impl(multilist_t *ml, size_t size, size_t offset, ASSERT3P(ml->ml_sublists, !=, NULL); - for (i = 0; i < ml->ml_num_sublists; i++) { + for (int i = 0; i < ml->ml_num_sublists; i++) { multilist_sublist_t *mls = &ml->ml_sublists[i]; mutex_init(&mls->mls_lock, NULL, MUTEX_NOLOCKDEP, NULL); list_create(&mls->mls_list, size, offset); } + return (ml); } /* - * Initialize a new sublist, using the default number of sublists + * Allocate a new multilist, using the default number of sublists * (the number of CPUs, or at least 4, or the tunable * zfs_multilist_num_sublists). */ -void -multilist_create(multilist_t *ml, size_t size, size_t offset, +multilist_t * +multilist_create(size_t size, size_t offset, multilist_sublist_index_func_t *index_func) { int num_sublists; @@ -113,7 +112,7 @@ multilist_create(multilist_t *ml, size_t size, size_t offset, num_sublists = MAX(boot_ncpus, 4); } - multilist_create_impl(ml, size, offset, num_sublists, index_func); + return (multilist_create_impl(size, offset, num_sublists, index_func)); } /* @@ -141,6 +140,7 @@ multilist_destroy(multilist_t *ml) ml->ml_num_sublists = 0; ml->ml_offset = 0; + kmem_free(ml, sizeof (multilist_t)); } /* @@ -294,6 +294,13 @@ multilist_sublist_lock(multilist_t *ml, unsigned int sublist_idx) return (mls); } +/* Lock and return the sublist that would be used to store the specified obj */ +multilist_sublist_t * +multilist_sublist_lock_obj(multilist_t *ml, void *obj) +{ + return (multilist_sublist_lock(ml, ml->ml_index_func(ml, obj))); +} + void multilist_sublist_unlock(multilist_sublist_t *mls) { diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c index bc5273e2e0..230c521569 100644 --- a/module/zfs/spa_misc.c +++ b/module/zfs/spa_misc.c @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011, 2015 by Delphix. All rights reserved. + * Copyright (c) 2011, 2017 by Delphix. All rights reserved. * Copyright 2015 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. * Copyright 2013 Saso Kiselkov. All rights reserved. @@ -612,7 +612,7 @@ spa_add(const char *name, nvlist_t *config, const char *altroot) if (altroot) spa->spa_root = spa_strdup(altroot); - avl_create(&spa->spa_alloc_tree, zio_timestamp_compare, + avl_create(&spa->spa_alloc_tree, zio_bookmark_compare, sizeof (zio_t), offsetof(zio_t, io_alloc_node)); /* diff --git a/module/zfs/zio.c b/module/zfs/zio.c index 8a3b3066ab..8c0543cf92 100644 --- a/module/zfs/zio.c +++ b/module/zfs/zio.c @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011, 2016 by Delphix. All rights reserved. + * Copyright (c) 2011, 2017 by Delphix. All rights reserved. * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. */ @@ -544,21 +544,37 @@ zio_inherit_child_errors(zio_t *zio, enum zio_child c) } int -zio_timestamp_compare(const void *x1, const void *x2) +zio_bookmark_compare(const void *x1, const void *x2) { const zio_t *z1 = x1; const zio_t *z2 = x2; - int cmp; - cmp = AVL_CMP(z1->io_queued_timestamp, z2->io_queued_timestamp); - if (likely(cmp)) - return (cmp); + if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset) + return (-1); + if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset) + return (1); - cmp = AVL_CMP(z1->io_offset, z2->io_offset); - if (likely(cmp)) - return (cmp); + if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object) + return (-1); + if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object) + return (1); - return (AVL_PCMP(z1, z2)); + if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level) + return (-1); + if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level) + return (1); + + if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid) + return (-1); + if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid) + return (1); + + if (z1 < z2) + return (-1); + if (z1 > z2) + return (1); + + return (0); } /* @@ -2953,8 +2969,6 @@ zio_dva_throttle(zio_t *zio) return (ZIO_PIPELINE_CONTINUE); if (nio != NULL) { - ASSERT3U(nio->io_queued_timestamp, <=, - zio->io_queued_timestamp); ASSERT(nio->io_stage == ZIO_STAGE_DVA_THROTTLE); /* * We are passing control to a new zio so make sure that