bg tree vs original mode, original mode best case

	B	C	D	E	F	G	H	I	J
1
2	nodesize	16k (default)
3	block device	LVM thin on HDD
4	fs total size	20T
5	fs used size	12T
6	fill method	fallocate -l 12T
7	mount options	nospace_cache
8
9	Original mode (unit is 'us')
10		run 1	run 2	run 3	run 4	run 5	avg	std
11	btrfs_read_chunk_tree	95597.03	89927.24	99403.79	96187.93	93275.24	94878.246	3528.26302
12	btrfs_verify_dev_extents	29566.17	53170.57	35627.19	36347.76	36308.11	38203.96	8835.868665
13	btrfs_read_block_groups	137859.9	112404.2	106444.5	134423.5	114337.6	121093.94	14093.7964
14	open_ctree	320052.5	632619.7	287016.2	320451.3	286457.1	369319.36	148140.4267
15
16	Bg-tree mode
17		run 1	run 2	run 3	run 4	run 5	avg	std	avg diff vs original
18	btrfs_read_chunk_tree	96098.85	94883.57	96214.74	100253.8	94385.84	96367.36	2309.104839	1.57%
19	btrfs_verify_dev_extents	37653.1	32242.2	33898.52	25417.92	32341.61	32310.67	4432.225003	-15.43%
20	btrfs_read_block_groups	80603.91	111682.7	78949.63	75458.63	70779.96	83494.966	16200.4684	-31.05%
21	open_ctree	274761.2	289783.2	257027.9	249991.1	249756.2	264263.92	17521.22894	-28.45%
22
23		leaves	nodes
24	bg tree (bg tree mode)	38	1
25	extent tree (original mode)	290	1
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