Re: [PATCH v3 01/18] block: introduce duration-limits priority class

Keith Busch
2023-01-25T23:11:49Z

On Wed, Jan 25, 2023 at 10:19:45AM +0900, Damien Le Moal wrote:
> On 1/25/23 09:05, Bart Van Assche wrote:
>
> > which it is not sure that it will be integrated in other storage
> > standards (NVMe, ...). Isn't the purpose of the block layer to provide
> > an interface that is independent of the specifics of a single storage
> > standard? This is why I'm in favor of letting the ATA core translate one
> > of the existing I/O priority classes into a CDL instead of introducing a
> > new I/O priority class (IOPRIO_CLASS_DL) in the block layer.
>
> We discussed CDL with Hannes in the context of NVMe over fabrics. Their
> may be interesting extensions to consider for NVMe in that context (the
> value for local PCI attached NVMe drive is more limited at best).

I wouldn't necessarily rule out CDL for PCI attached in some future TP. NVMe
does allow rotating media, and they'll want feature parity if CDL is considered
useful in other protocols.