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

Damien Le Moal
2023-01-26T00:08:46Z

On 2023/01/26 8:11, Keith Busch wrote:
> 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.

True. If NVMe HDDs come to market, we'll definitely want a CDL feature too.

--
Damien Le Moal
Western Digital Research