On 3/27/20 8:25 AM, Keith Busch wrote: > On 3/27/20 12:14 AM, Alexey Dobriyan wrote: >> On Fri, Mar 27, 2020 at 12:56:00AM +0000, Damien Le Moal wrote: >>> >>> On 2020/03/27 5:44, Alexey Dobriyan wrote: >>>> Add simple iodepth=1 NVMe engine: >>>> >>>> ioengine=nvme >>>> >>>> It works via standard Linux NVMe ioctls. >>> Keith is working on splitting up nvmecli into the cli part and libnvme which >>> uses the kernel ioctl iinterface for NVMe command passthrough. So I think it may >>> be better to implement ioengine=libnvme using Keith libnvme library. That will >>> remove the need to define all the NVMe command stuff here. >> Sure. It is just standalone file you can send to colleagues and forget. >> Similar to how header-only C++ libraries work. >> >>>> It will be used for testing upcoming ZNS stuff. > > > > I'm not completely against fio providing an nvme ioengine, and libnvme > could easily fit in, but I don't think that faithfully represents how > these devices are actually used. The passthrough interface is not really > our fast path, and being a synchronous interface is a bit limiting in > testing device capabilities. I guess my main question is what purpose it fills. Since it's not a performant interface, it's not a benchmarking thing. Hence it's for testing the feature? If so, would it be better to have in nvme-cli or a standalone tool? -- Jens Axboe
