Re: [RFC] bdev: use bdev_io_min() for statx DIO min IO

Christoph Hellwig
2024-06-29T06:25:46Z

On Fri, Jun 28, 2024 at 02:23:50PM -0700, Luis Chamberlain wrote:
> We currently rely on the block device logical block size for the
> offset alignment. While this *works* it doesn't work with performance
> in mind. That's exactly what the minimum_io_size attribute is for.
>
> This would for example enhance performance for DIO on 4k IU drives which
> have for example an LBA format of 512 bytes for both HDDs and NVMe.
> Another use case is to ensure that DIO will be used with 16k IOs on
> existing market 16k IU drives with an LBA format of 4k or 512 bytes.

The minimum_io_size clearly is the minimum I/O size, not the minimal
nice to have one. Changing this will break existing setups.