Hello, I'm reporting a performance regression after the commit below on phoronix pts/fio test and with the config that is added in the end of this email: Link: https://lore.kernel.org/all/20210913131123.597544850@xxxxxxxxxxxxxxxxxxx/ commit 7b3188e7ed54102a5dcc73d07727f41fb528f7c8 Author: Jens Axboe axboe@xxxxxxxxx Date: Mon Aug 30 19:37:41 2021 -0600 io_uring: IORING_OP_WRITE needs hash_reg_file set We observed regression on the latest v6.1.y and v5.15.y upstream kernels (Haven't tested other stable kernels). We noticed that performance regression improved 45% after the revert of the commit above. All of the benchmarks below have experienced around ~45% regression. phoronix-pts-fio-1.15.0-RandomWrite-EngineIO_uring-BufferedNo-DirectYes-BlockSize4KB-MB-s_xfs phoronix-pts-fio-1.15.0-SequentialWrite-EngineIO_uring-BufferedNo-DirectYes-BlockSize4KB-MB-s_xfs phoronix-pts-fio-1.15.0-SequentialWrite-EngineIO_uring-BufferedYes-DirectNo-BlockSize4KB-MB-s_xfs We tend to see this regression on 4KB BlockSize tests. We tried out changing force_async but that has no effect on the result. Also, backported a modified version of the patch mentioned here (https://lkml.org/lkml/2022/7/20/854) but that didn't affect performance. Do you have any suggestions on any fixes or what else we can try to narrow down the issue? Thanks a bunch, Saeed -------- Here is more info on the benchmark and system: Here is the config for fio: [global] rw=randwrite ioengine=io_uring iodepth=64 size=1g direct=1 buffered=0 startdelay=5 force_async=4 ramp_time=5 runtime=20 time_based disk_util=0 clat_percentiles=0 disable_lat=1 disable_clat=1 disable_slat=1 filename=/data/fiofile [test] name=test bs=4k stonewall df -Th output (file is on /data/): Filesystem Type Size Used Avail Use% Mounted on devtmpfs devtmpfs 252G 0 252G 0% /dev tmpfs tmpfs 252G 0 252G 0% /dev/shm tmpfs tmpfs 252G 18M 252G 1% /run tmpfs tmpfs 252G 0 252G 0% /sys/fs/cgroup /dev/mapper/ocivolume-root xfs 89G 17G 73G 19% / /dev/mapper/ocivolume-oled xfs 10G 143M 9.9G 2% /var/oled /dev/sda2 xfs 1014M 643M 372M 64% /boot /dev/sda1 vfat 100M 5.0M 95M 6% /boot/efi tmpfs tmpfs 51G 0 51G 0% /run/user/0 tmpfs tmpfs 51G 0 51G 0% /run/user/987 /dev/mapper/tank-lvm xfs 100G 1.8G 99G 2% /data
