On Wed, Jan 25, 2023 at 10:19:45AM +0900, Damien Le Moal wrote:

On 1/25/23 09:05, Bart Van Assche wrote:

quoted

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.