Thanks, mircea. Sounds AMD Sempron serial CPU only supports HyperTransport, and SMT is Intel's. HyperTransport is not the same with SMT, right?
So, for my cpu, it is better to disable SMP? I enabled CONFIG_PREEMPT, so CONFIG_SMP is no additional overhead for spin_lock, right? Except for spin_lock, are there any other overhead for CONFIG_SMP for single-core cpu? Thank you. BR, Peter chen On Sun, 2009-03-22 at 13:12 +0200, Mircea Gherzan wrote: > Hi, > > Peter Chen <[email protected]> wrote: > > 1. Does SMP technology can be only used at Dual-core processor, or > > only Dual-core processor can get benefit from SMP technology? > > > > Not only on dual-core CPUs, but also on SMT (HyperThreading) ones, if > the SMT option in the kernel config is enabled. > > > 2. If mine cpu is single-core and I enabled SMP, which will happen? > > You will get some overhead in the spinlock code. On non-SMP kernel, a > spinlock acquire is reduced to disabling preemption (if preemption is > enabled, of course), or it's "compiled out" if there's not preemption > at all. SMP adds "real" spinning (busy-waiting) code. >
