diff --git a/include/sys/dbuf.h b/include/sys/dbuf.h
index d221eac4c8..6ae079c6a6 100644
--- a/include/sys/dbuf.h
+++ b/include/sys/dbuf.h
@@ -322,12 +322,12 @@ typedef struct dmu_buf_impl {
 } dmu_buf_impl_t;
 
 /* Note: the dbuf hash table is exposed only for the mdb module */
-#define	DBUF_MUTEXES 8192
+#define	DBUF_MUTEXES 2048
 #define	DBUF_HASH_MUTEX(h, idx) (&(h)->hash_mutexes[(idx) & (DBUF_MUTEXES-1)])
 typedef struct dbuf_hash_table {
 	uint64_t hash_table_mask;
 	dmu_buf_impl_t **hash_table;
-	kmutex_t hash_mutexes[DBUF_MUTEXES];
+	kmutex_t hash_mutexes[DBUF_MUTEXES] ____cacheline_aligned;
 } dbuf_hash_table_t;
 
 typedef void (*dbuf_prefetch_fn)(void *, boolean_t);
diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 3484fff3b4..394ca1bfe4 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -740,29 +740,18 @@ taskq_t *arc_prune_taskq;
  * Hash table routines
  */
 
-#define	HT_LOCK_ALIGN	64
-#define	HT_LOCK_PAD	(P2NPHASE(sizeof (kmutex_t), (HT_LOCK_ALIGN)))
-
-struct ht_lock {
-	kmutex_t	ht_lock;
-#ifdef _KERNEL
-	unsigned char	pad[HT_LOCK_PAD];
-#endif
-};
-
-#define	BUF_LOCKS 8192
+#define	BUF_LOCKS 2048
 typedef struct buf_hash_table {
 	uint64_t ht_mask;
 	arc_buf_hdr_t **ht_table;
-	struct ht_lock ht_locks[BUF_LOCKS];
+	kmutex_t ht_locks[BUF_LOCKS] ____cacheline_aligned;
 } buf_hash_table_t;
 
 static buf_hash_table_t buf_hash_table;
 
 #define	BUF_HASH_INDEX(spa, dva, birth) \
 	(buf_hash(spa, dva, birth) & buf_hash_table.ht_mask)
-#define	BUF_HASH_LOCK_NTRY(idx) (buf_hash_table.ht_locks[idx & (BUF_LOCKS-1)])
-#define	BUF_HASH_LOCK(idx)	(&(BUF_HASH_LOCK_NTRY(idx).ht_lock))
+#define	BUF_HASH_LOCK(idx)	(&buf_hash_table.ht_locks[idx & (BUF_LOCKS-1)])
 #define	HDR_LOCK(hdr) \
 	(BUF_HASH_LOCK(BUF_HASH_INDEX(hdr->b_spa, &hdr->b_dva, hdr->b_birth)))
 
@@ -1111,7 +1100,7 @@ buf_fini(void)
 	    (buf_hash_table.ht_mask + 1) * sizeof (void *));
 #endif
 	for (i = 0; i < BUF_LOCKS; i++)
-		mutex_destroy(&buf_hash_table.ht_locks[i].ht_lock);
+		mutex_destroy(BUF_HASH_LOCK(i));
 	kmem_cache_destroy(hdr_full_cache);
 	kmem_cache_destroy(hdr_full_crypt_cache);
 	kmem_cache_destroy(hdr_l2only_cache);
@@ -1276,10 +1265,8 @@ retry:
 		for (ct = zfs_crc64_table + i, *ct = i, j = 8; j > 0; j--)
 			*ct = (*ct >> 1) ^ (-(*ct & 1) & ZFS_CRC64_POLY);
 
-	for (i = 0; i < BUF_LOCKS; i++) {
-		mutex_init(&buf_hash_table.ht_locks[i].ht_lock,
-		    NULL, MUTEX_DEFAULT, NULL);
-	}
+	for (i = 0; i < BUF_LOCKS; i++)
+		mutex_init(BUF_HASH_LOCK(i), NULL, MUTEX_DEFAULT, NULL);
 }
 
 #define	ARC_MINTIME	(hz>>4) /* 62 ms */
diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
index 9ce091b80d..289247c6ed 100644
--- a/module/zfs/dbuf.c
+++ b/module/zfs/dbuf.c
@@ -826,12 +826,12 @@ dbuf_init(void)
 	int i;
 
 	/*
-	 * The hash table is big enough to fill all of physical memory
+	 * The hash table is big enough to fill one eighth of physical memory
 	 * with an average block size of zfs_arc_average_blocksize (default 8K).
 	 * By default, the table will take up
 	 * totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers).
 	 */
-	while (hsize * zfs_arc_average_blocksize < physmem * PAGESIZE)
+	while (hsize * zfs_arc_average_blocksize < arc_all_memory() / 8)
 		hsize <<= 1;
 
 retry:
@@ -3055,8 +3055,8 @@ dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
 	db->db_state = DB_EVICTING; /* not worth logging this state change */
 	if ((odb = dbuf_hash_insert(db)) != NULL) {
 		/* someone else inserted it first */
-		kmem_cache_free(dbuf_kmem_cache, db);
 		mutex_exit(&dn->dn_dbufs_mtx);
+		kmem_cache_free(dbuf_kmem_cache, db);
 		DBUF_STAT_BUMP(hash_insert_race);
 		return (odb);
 	}