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7500 Simplify dbuf_free_range by removing dn_unlisted_l0_blkid

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illumos/illumos-gate@653af1b809
653af1b809

https://www.illumos.org/issues/7500
  With the integration of:

    commit 0f6d88aded0d165f5954688a9b13bac76c38da84
    Author: Alex Reece <alex@delphix.com>
    Date:   Sat Jul 26 13:40:04 2014 -0800
    4873 zvol unmap calls can take a very long time for larger datasets

  the dnode's dn_bufs field was changed from a list to a tree. As a result,
  the dn_unlisted_l0_blkid field is no longer necessary.

Author: Stephen Blinick <stephen.blinick@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Gordon Ross <gordon.w.ross@gmail.com>
This commit is contained in:
Josh Paetzel 2017-02-16 01:44:56 +00:00
parent 1e37d7e555
commit 281825cdf1
3 changed files with 5 additions and 44 deletions
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40
uts/common/fs/zfs/dbuf.c
View File

@ -49,12 +49,6 @@
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);
@ -1220,9 +1214,6 @@ 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,
@ -1232,10 +1223,9 @@ 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);
@ -1244,29 +1234,9 @@ 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
mutex_exit(&dn->dn_dbufs_mtx);
return;
} 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) {
@ -2283,9 +2253,7 @@ 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_OTHER);

7
uts/common/fs/zfs/dnode.c
View File

@ -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.
* Copyright (c) 2014 Integros [integros.com]
*/
@ -151,7 +151,6 @@ 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));
@ -204,7 +203,6 @@ 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);
}
@ -522,7 +520,6 @@ 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);
@ -758,7 +755,6 @@ 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;
@ -791,7 +787,6 @@ 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;

2
uts/common/fs/zfs/sys/dnode.h
View File

@ -195,8 +195,6 @@ 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 */