Hi Martin, On Fri, Sep 1, 2017 at 8:52 AM, Martin K. Petersen <martin.petersen@xxxxxxxxxx> wrote: > > 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." > > -- The statement in description of patch 4 is added by mistake, We ll correct the description and re sending that. > Martin K. Petersen Oracle Linux Engineering Thanks, Suganath Prabu S
