On 31/08/18 10:19 AM, Jonathan Cameron wrote: > This feels like a somewhat simplistic starting point rather than a > generally correct estimate to use. Should we be taking the bandwidth of > those links into account for example, or any discoverable latencies? > Not all PCIe switches are alike - particularly when it comes to P2P. I don't think this is necessary. There won't typically be a ton of choice in terms of devices to use and if there is, the hardware will probably be fairly homogenous. For example, it would be unusual to have an NVMe drive on a x4 and another one on an x8. Or mixing say Gen3 switches with Gen4 would also be very strange. In weird unusual cases like this where the user specifically wants to use a faster device they can specify the specific device in the configfs interface. I think the latency would probably be proportional to the distance which is what we are already using. > I guess that can be a topic for future development if it turns out people > have horrible mixed systems. Yup! Logan
