Re: Spinlocks, yet again: analysis and proposed patches

Kurt Roeckx <kurt@roeckx.be> writes:
> On Sun, Sep 11, 2005 at 05:59:49PM -0400, Tom Lane wrote:
>> I kinda suspect that the cmpb test is a no-op or loss on all
>> Intelish processors:

> I think an important question is wether this is for x86_64 in
> general, of opteron specific.  It could be that it's not the same
> on Intel's EM64Ts.

Good point --- anyone have one to try?

> Something else to consider is the OS you're using.  I've been
> told that Linux isn't that good in NUMA and FreeBSD might be
> better.

It's hard to see how the OS could affect behavior at the level of
processor cache operations --- unless they did something truly
spectacularly stupid, like mark main memory non-cacheable.
        regards, tom lane