> We discussed this on tesla before, TSC has high resolution and best > performance and > it is widely used in the kernel. Switching to other time sources will > take the big effort > which we don't think it's worth to do. Yes. Compared to the efforts, it is not worth to enable it on pre-Nehalem CPUs. > Intel CPU offers invariant TSC in deeper > c-state on Nehalem and later processors. That means deep c-state is > easy to support > from now on. HPET here is used as a proxy of local apic timer since > local apic timer still > stops in C3 on Nehalem. Fall back to PIT if system has no HPET ? LAPIC timer won't stop starting from Westmere. So, seems that Solaris doesn't make full use of the time intr proxy scheme which you guys made great efforts to implement, and it is used by Nehalem only.
> If the community can enable deep c-state on pre-nehalem > processors without any perf & power penalty, we'll be glad to accept the work I think so :) -minskey
