On Tue, Jan 17, 2023 at 05:06:52PM +0900, Damien Le Moal wrote: > They can, by using a large limit for "low priority" IOs. But then, these > would still have a limit while any IO issued simultaneously without a CDL > index specified would have no limit at all. So strictly speaking, the no > limit IOs should be considered as even lower priority that CDL IOs with > large limits. > > The other aspect here is that on ATA drives, CDL and NCQ priority cannot > be used together. A mix of CDL and high priority commands cannot be sent > to a device. Combining this with the above thinking, it made sense to me > to have the CDL priority class handled the same as the RT class (as that > is the one that maps to ATA NCQ high prio commands). Ok. Maybe document this a bit better in the commit log.
