Hi Suganath, > Let me explain - NVME device fast path is possible in two ways. IEEE > SGL and PRP SGL. Due to h/w constraint we choose IEEE SGL only for > smaller IO size. Both above is true h/w Fast Path and no firmware > involvement. > Agree with you. We are planning to see if we can keep only simple Fast > Path using only PRP. That would be great, thank you! > Currently there is no performance issue for UNMAP translation in FW. Good! >> And yet patch 4 circumvents that statement by adding support for >> encapsulated commands to bypass the FW translation... > > This path is not due to performance reason. User wants to interact > with NVME drive in native NVME command for management. Patch 4 states: "This encapsulated NVMe command is used by applications to send direct NVMe commands to NVMe drives or for handling unmap where the translation at controller/firmware level is having performance issues." -- Martin K. Petersen Oracle Linux Engineering
