Kashyap, > AMD EPYC is not efficient w.r.t QPI transaction. [...] > Same test on Intel architecture provides better result Heuristics are always hard. However, you are making assumptions based on observed performance of current Intel offerings vs. current AMD offerings. This results in what is inevitably going to be a short-lived heuristic in the kernel. Things could easily be reversed in next generation platforms from these vendors. So while I appreciate that the logic works given the machines you are currently testing, I think CPU manufacturer is a horrible heuristic. You are stating "This will be the right choice for all future processors manufactured by Intel". That's a bit of a leap of faith. Instead of predicting the future I prefer to make decisions based on things we know. Measured negative impact on current EPYC family, for instance. That's a fairly well-defined and narrow scope. That said, I am still not a big fan of platform-specific tweaks in drivers. While I prefer the kernel to do the right thing out of the box, I think the module parameter is probably the better choice in this case. -- Martin K. Petersen Oracle Linux Engineering
