I was referring to extensions to the command set the OS uses to interact with the drive itself. Some of these are quite like a madvise() call, but at a lower layer. Others permit the drive to expose a bit more information to the OS so that it can better optimize its IO patterns. I summarized the most recently standardized changes at [1], but there are several other features in the NVMe spec [2] that fall into this category. The extension for IO determinism has been approved for the next standard but the official spec for it hasn't been published. (I'm referring here mostly to NVMe stuff, but there are SCSI/SAS analogs to many of these features.)

[1] https://www.anandtech.com/show/11436/nvme-13-specification-p...

[2] http://www.nvmexpress.org/resources/specifications/