Segfault on Older CPUs about cult

[kobalicek]

Hello, thanks for the report. It seems your CPU doesn't have RDTSCP instruction so it uses another code path that unfortunately doesn't work in user-space - my fault, I just implemented it based on an Intel paper without checking it has to run in kernel-space.

I will fix this tonight, however I'm not sure about the max error

[billyauhk]

Thanks for the explanation. I have to look up Intel manual and confirmed that RDTSCP is not available (It says "Support for RDTSCP is indicated by CPUID.80000001H:EDX[27]").

So "the other code path" is using RDTSC+CPUID to achieve the same effect but I still cannot understand why "mov %cr0, %rax" is generated (and why "mov %rax, %cr0" next to it). Any pointers to relevant portion of the code in the repository?

[kobalicek]

Closing as this should already be fixed.