HLT instruction on Opterons?

[Brian Hall]

If the Linux kernel issues a HLT instruction to
an Opteron in a dual-CPU system while in an idle
loop, are there any power savings from this or is
it just ignored?

 

[Ben Pope]

If the Linux kernel issues a HLT instruction to
an Opteron in a dual-CPU system while in an idle
loop, are there any power savings from this or is
it just ignored?

I'm not sure of it's relevance, but my nForce2 chipset on an Athlon XP
effectively does that itself.

You could check dmesg, there's a check that displays it's output when you
boot, but then, who knows how accurate "OK" is

Ben