Re: [PATCH v6 0/3] iomap: add simple dio path for small direct I/O

[Christian Brauner]

On Wed, 01 Jul 2026 11:32:50 +0800, Fengnan Chang wrote:
> iomap: add simple dio path for small direct I/O
> 
> When running 4K random read workloads on high-performance Gen5 NVMe
> SSDs, the software overhead in the iomap direct I/O path
> (__iomap_dio_rw) becomes a significant bottleneck.
> 
> Using io_uring with poll mode for a 4K randread test on a raw block
> device:
> taskset -c 30 ./t/io_uring -p1 -d512 -b4096 -s32 -c32 -F1 -B1 -R1 -X1
> -n1 -P1 /dev/nvme10n1
> Result: ~3.2M IOPS
> 
> [...]

Applied to the vfs-7.3.iomap branch of the vfs/vfs.git tree.
Patches in the vfs-7.3.iomap branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.3.iomap

[1/3] iomap: factor out iomap_dio_alignment helper
      https://git.kernel.org/vfs/vfs/c/acb8815f181f
[2/3] iomap: pass error code to should_report_dio_fserror directly
      https://git.kernel.org/vfs/vfs/c/281e3e52acbf
[3/3] iomap: add simple dio path for small direct I/O
      https://git.kernel.org/vfs/vfs/c/de2f9ebea176