STI, HLT in acpi_cpu_idle_c1
jhb at FreeBSD.org
Tue Jun 22 22:05:08 GMT 2004
On Tuesday 22 June 2004 05:34 pm, Matthew Dillon wrote:
> :On Thursday 17 June 2004 07:33 pm, Matthew Dillon wrote:
> :> It kinda sounds like ACPI has bokered the other cpus. I'm not sure
> :> why one would even *want* to use ACPI to idle down Xeon's in an MP
> :> system, actually :-)
> :Power and heat savings.
> :John Baldwin <jhb at FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
> All well and nice, but if you want power and heat savings you don't
> purchase a big honking SMP box in the first place.
> This sounds like a disaster waiting to happen to me. ACPI barely works
> on UP systems, there is no way I would ever trust it to properly HLT or
> otherwise screw around with the cpu timing on an SMP system. HLT is
> plenty good enough. IMHO this type of feature is not something that
> should be turned on by default on SMP.
Certain large CPU vendors disagree.
John Baldwin <jhb at FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve" = http://www.FreeBSD.org
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