From: George Melikov Date: Thu, 26 Jan 2017 23:15:48 +0000 (+0300) Subject: OpenZFS 7500 - Simplify dbuf_free_range by removing dn_unlisted_l0_blkid X-Git-Tag: zfs-0.7.12~600 X-Git-Url: https://git.proxmox.com/?p=mirror_zfs.git;a=commitdiff_plain;h=9c9531cb6f085174e90d1262aba177ffb8b88753 OpenZFS 7500 - Simplify dbuf_free_range by removing dn_unlisted_l0_blkid Authored by: Stephen Blinick Reviewed by: Matthew Ahrens Reviewed by: Dan Kimmel Approved by: Gordon Ross Reviewed-by: Brian Behlendorf Ported-by: George Melikov OpenZFS-issue: https://www.illumos.org/issues/7500 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/653af1b Closes #5639 --- diff --git a/include/sys/dnode.h b/include/sys/dnode.h index 9ecb9b64f..9aacac3df 100644 --- a/include/sys/dnode.h +++ b/include/sys/dnode.h @@ -236,8 +236,6 @@ struct dnode { /* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */ uint32_t dn_dbufs_count; /* count of dn_dbufs */ - /* There are no level-0 blocks of this blkid or higher in dn_dbufs */ - uint64_t dn_unlisted_l0_blkid; /* protected by os_lock: */ list_node_t dn_dirty_link[TXG_SIZE]; /* next on dataset's dirty */ diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c index 907a84941..ebb95ddb8 100644 --- a/module/zfs/dbuf.c +++ b/module/zfs/dbuf.c @@ -74,11 +74,6 @@ static void __dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh, static int __dbuf_hold_impl(struct dbuf_hold_impl_data *dh); uint_t zfs_dbuf_evict_key; -/* - * Number of times that zfs_free_range() took the slow path while doing - * a zfs receive. A nonzero value indicates a potential performance problem. - */ -uint64_t zfs_free_range_recv_miss; static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx); static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx); @@ -1340,9 +1335,6 @@ dbuf_unoverride(dbuf_dirty_record_t *dr) * Evict (if its unreferenced) or clear (if its referenced) any level-0 * data blocks in the free range, so that any future readers will find * empty blocks. - * - * This is a no-op if the dataset is in the middle of an incremental - * receive; see comment below for details. */ void dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, @@ -1352,10 +1344,9 @@ dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, dmu_buf_impl_t *db, *db_next; uint64_t txg = tx->tx_txg; avl_index_t where; - boolean_t freespill = - (start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID); - if (end_blkid > dn->dn_maxblkid && !freespill) + if (end_blkid > dn->dn_maxblkid && + !(start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID)) end_blkid = dn->dn_maxblkid; dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid); @@ -1365,28 +1356,9 @@ dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, db_search->db_state = DB_SEARCH; mutex_enter(&dn->dn_dbufs_mtx); - if (start_blkid >= dn->dn_unlisted_l0_blkid && !freespill) { - /* There can't be any dbufs in this range; no need to search. */ -#ifdef DEBUG - db = avl_find(&dn->dn_dbufs, db_search, &where); - ASSERT3P(db, ==, NULL); - db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); - ASSERT(db == NULL || db->db_level > 0); -#endif - goto out; - } else if (dmu_objset_is_receiving(dn->dn_objset)) { - /* - * If we are receiving, we expect there to be no dbufs in - * the range to be freed, because receive modifies each - * block at most once, and in offset order. If this is - * not the case, it can lead to performance problems, - * so note that we unexpectedly took the slow path. - */ - atomic_inc_64(&zfs_free_range_recv_miss); - } - db = avl_find(&dn->dn_dbufs, db_search, &where); ASSERT3P(db, ==, NULL); + db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); for (; db != NULL; db = db_next) { @@ -1459,7 +1431,6 @@ dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, mutex_exit(&db->db_mtx); } -out: kmem_free(db_search, sizeof (dmu_buf_impl_t)); mutex_exit(&dn->dn_dbufs_mtx); } @@ -2416,9 +2387,7 @@ dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid, return (odb); } avl_add(&dn->dn_dbufs, db); - if (db->db_level == 0 && db->db_blkid >= - dn->dn_unlisted_l0_blkid) - dn->dn_unlisted_l0_blkid = db->db_blkid + 1; + db->db_state = DB_UNCACHED; mutex_exit(&dn->dn_dbufs_mtx); arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF); diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c index 4c37ce383..be12ac0fe 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, 2015 by Delphix. All rights reserved. + * Copyright (c) 2012, 2016 by Delphix. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. */ @@ -141,7 +141,6 @@ dnode_cons(void *arg, void *unused, int kmflag) dn->dn_id_flags = 0; dn->dn_dbufs_count = 0; - dn->dn_unlisted_l0_blkid = 0; avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), offsetof(dmu_buf_impl_t, db_link)); @@ -194,7 +193,6 @@ dnode_dest(void *arg, void *unused) ASSERT0(dn->dn_id_flags); ASSERT0(dn->dn_dbufs_count); - ASSERT0(dn->dn_unlisted_l0_blkid); avl_destroy(&dn->dn_dbufs); } @@ -515,7 +513,6 @@ dnode_destroy(dnode_t *dn) dn->dn_newuid = 0; dn->dn_newgid = 0; dn->dn_id_flags = 0; - dn->dn_unlisted_l0_blkid = 0; dmu_zfetch_fini(&dn->dn_zfetch); kmem_cache_free(dnode_cache, dn); @@ -766,7 +763,6 @@ dnode_move_impl(dnode_t *odn, dnode_t *ndn) ASSERT(avl_is_empty(&ndn->dn_dbufs)); avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); ndn->dn_dbufs_count = odn->dn_dbufs_count; - ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; ndn->dn_bonus = odn->dn_bonus; ndn->dn_have_spill = odn->dn_have_spill; ndn->dn_zio = odn->dn_zio; @@ -799,7 +795,6 @@ dnode_move_impl(dnode_t *odn, dnode_t *ndn) avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), offsetof(dmu_buf_impl_t, db_link)); odn->dn_dbufs_count = 0; - odn->dn_unlisted_l0_blkid = 0; odn->dn_bonus = NULL; odn->dn_zfetch.zf_dnode = NULL;