On Sep 16, 2011, at 8:07 AM, John Baldwin wrote:
> I think the "right" way for an admin to disable HTT is to disable it in the
> BIOS so that it doesn't show up in the MADT. Back when we were doing the
> MPTABLE_FORCE_HTT hack having a separate tunable made sense (and it possibly
> made some limi
On Wednesday, September 14, 2011 4:02:41 pm Andrew Boyer wrote:
>
> On Sep 14, 2011, at 3:56 PM, Andriy Gapon wrote:
>
> > on 14/09/2011 20:59 Andrew Boyer said the following:
> >> When FreeBSD examines the CPU topology using CPUID leaf 11 in
> >> topo_probe_0xb(), it never sets hyperthreading_cp
on 14/09/2011 23:02 Andrew Boyer said the following:
> Actually, it's not useless. If you don't set it to something other than zero
> the machdep.hyperthreading_allowed tunable doesn't do anything, since it
> can't tell which CPUs are actually HTT.
Ah, you are right.
That works correctly with my
On Sep 14, 2011, at 3:56 PM, Andriy Gapon wrote:
> on 14/09/2011 20:59 Andrew Boyer said the following:
>> When FreeBSD examines the CPU topology using CPUID leaf 11 in
>> topo_probe_0xb(), it never sets hyperthreading_cpus. At the end of
>> topo_probe_0x4() it sets hyperthreading_cpus = cpu_log
on 14/09/2011 20:59 Andrew Boyer said the following:
> When FreeBSD examines the CPU topology using CPUID leaf 11 in
> topo_probe_0xb(), it never sets hyperthreading_cpus. At the end of
> topo_probe_0x4() it sets hyperthreading_cpus = cpu_logical.
>
> Adding that assignment to line 316 of sys/amd
When FreeBSD examines the CPU topology using CPUID leaf 11 in topo_probe_0xb(),
it never sets hyperthreading_cpus. At the end of topo_probe_0x4() it sets
hyperthreading_cpus = cpu_logical.
Adding that assignment to line 316 of sys/amd64/amd64/mp_machdep.c seems to do
the right thing on a syste
