AMD Ryzen CPUs Will Need Modern Linux Kernel For Proper Support, Just Like Windows
It seems that Windows is not the only OS that will be playing the “latest version” card. The same is the case with Linux. Linux users will need kernel version 4.9.10 or above in order to take full advantage of the features that AMD Ryzen CPUs have to offer. SMT is one of those features.
Having an older version does not mean that you will not be able to use the AMD Ryzen CPUs, it means that they will not be supported fully by the older version of the OS. You will need the newer versions for better support.
It also means that if you encounter an issue then you will either need to upgrade or live with that issue until you decide to give in and upgrade.
This is as we have seen with Windows 7 as AMD Ryzen CPUs will not fully support the older OS and in order to take advantage of all the features that Ryzen has to offer users will need to use Windows 10.
After: a33d331761bc (“x86/CPU/AMD: Fix Bulldozer topology”) our SMT scheduling topology for Fam17h systems is broken, because the ThreadId is included in the ApicId when SMT is enabled. So, without further decoding cpu_core_id is unique for each thread rather than the same for threads on the same core. This didn’t affect systems with SMT disabled. Make cpu_core_id be what it is defined to be.
This does mean that microcode has something to do with these features and that Microsoft claims are not simply made up and hold some merit. Still that this is not something that users on the older versions of these operating systems will appreciate.
Let us know what you think about this issue and whether or not you will consider upgrading to a newer version of you OS in order to use the upcoming AMD Ryzen CPUs.