Hi,

On 4.02.21 г. 5:17 ч., Wang Yugui wrote:

quoted

Hi,

I tried to run btrfs misc-next(5.11-rc6 +81patches) based on linux LTS
5.10.12 with the same other kernel components and the same kernel config.

Better dbench(sync open) result on both Throughput and max_latency.

If i understand correctly you rebased current misc-next to 5.10.12, if
so this means there is something else in the main kernel, that's not
btrfs related which degrades performance, it seems you've got a 300ms
win by running on 5.10 as compared on 5.11-rc6-based misc next, is that
right?

Yes.

maybye some code rather than btrfs in main kernel 5.11.rc6 have degrades
performance.
or maybe just because of different kernel config.
kernel config I used:
https://kojipkgs.fedoraproject.org/packages/kernel/5.11.0/0.rc6.141.eln108/
https://kojipkgs.fedoraproject.org/packages/kernel/5.10.12/200.fc33/

I rebased current misc-next to 5.10.12, so that there is only diff in
btrfs source code.

only 3 minor patch needed for this rebase, there seems no broken kernel API
 change for btrfs between 5.10 and 5.11.
# add-to-5.10  0001-block-add-a-bdev_kobj-helper.patch
# drop-from-btrs-misc-next  0001-block-remove-i_bdev.patch
# fix-to-btrfs-misc-next  	0001-btrfs-bdev_nr_sectors.patch

more patch come into misc-next today, they are yet not rebased/tested.

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2021/02/04