The Linux kernel may choose to not select TSC as the clocksource, regardless of the configuration. For example, we have a 4 socket machine running CentOS 6 that

The Linux kernel may choose to not select TSC as the clocksource, regardless of the configuration. For example, we have a 4 socket machine running CentOS 6 that refuses to use the TSC timer because at boot time the kernel determines (experimentally, I believe) that TSC is not reliable on that hardware. So it falls back to using HPET instead. We also have a similar 2 socket machine running a similar version of CentOS that has no problems using TSC. ¯\_(ツ)_/¯