Re: gfs2 write bandwidth regression on 6.4-rc3 compareto 5.15.y

[Wang Yugui <wangyugui@e16-tech.com>]

Hi,

> Hi,
> 
> gfs2 write bandwidth regression on 6.4-rc3 compare to 5.15.y.
> 
> we added  linux-xfs@ and linux-fsdevel@ because some related problem[1]
> and related patches[2].
> 
> we compared 6.4-rc3(rather than 6.1.y) to 5.15.y becasue some related patches[2]
> work only for 6.4 now.
> 
> [1] https://lore.kernel.org/linux-xfs/20230508172406.1CF3.409509F4@e16-tech.com/
> [2] https://lore.kernel.org/linux-xfs/20230520163603.1794256-1-willy@infradead.org/
> 
> 
> test case:
> 1) PCIe3 SSD *4 with LVM
> 2) gfs2 lock_nolock
>     gfs2 attr(T) GFS2_AF_ORLOV
>    # chattr +T /mnt/test
> 3) fio
> fio --name=global --rw=write -bs=1024Ki -size=32Gi -runtime=30 -iodepth 1
> -ioengine sync -zero_buffers=1 -direct=0 -end_fsync=1 -numjobs=1 \
> 	-name write-bandwidth-1 -filename=/mnt/test/sub1/1.txt \
> 	-name write-bandwidth-2 -filename=/mnt/test/sub2/1.txt \
> 	-name write-bandwidth-3 -filename=/mnt/test/sub3/1.txt \
> 	-name write-bandwidth-4 -filename=/mnt/test/sub4/1.txt
> 4) patches[2] are applied to 6.4-rc3.
> 
> 
> 5.15.y result
> 	fio WRITE: bw=5139MiB/s (5389MB/s),
> 6.4-rc3 result
> 	fio  WRITE: bw=2599MiB/s (2725MB/s)

more test result:

5.17.0	WRITE: bw=4988MiB/s (5231MB/s)
5.18.0	WRITE: bw=5165MiB/s (5416MB/s)
5.19.0	WRITE: bw=5511MiB/s (5779MB/s)
6.0.5	WRITE: bw=3055MiB/s (3203MB/s),	WRITE: bw=3225MiB/s (3382MB/s)
6.1.30	WRITE: bw=2579MiB/s (2705MB/s)

so this regression  happen in some code introduced in 6.0,
and maybe some minor regression in 6.1 too?

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2023/05/28