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.
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BR, Peter chen |
On Sun, 2009-03-22 at 13:12 +0200, Mircea Gherzan wrote:
Hi, Peter Chen <hzpeterchen@xxxxxxxxx> 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.
