Re: [BUG? -rc7] SMP: Just one CPU activated: P4 3GHz HT

From: Miguel Ojeda
Date: Mon Apr 23 2007 - 04:12:19 EST


On 4/22/07, Luca Tettamanti <kronos.it@xxxxxxxxx> wrote:
Probably the two siblings are enumerated only in ACPI tables. If you
disable ACPI the kernel won't be aware of the second "core".

Luca
--
"Su cio` di cui non si puo` parlare e` bene tacere".
Ludwig Wittgenstein


On 4/23/07, Robert Hancock <hancockr@xxxxxxx> wrote:

You didn't enable ACPI, it's needed for almost all systems to detect HT
and also for many systems to detect multi-cores as well.

Aside from that, in general I would say that on any modern x86 system
ACPI should always be enabled. In many cases it seems the BIOS code is
not tested much without ACPI anymore, so going without ACPI can be
problematic.

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@xxxxxxxxxxxxx
Home Page: http://www.roberthancock.com/



Thanks all of you. It seems the problem is ACPI, however, should not
it be noted in some way? Maybe at Documentation/smp.txt, maybe at the
help section at CONFIG_SMP, maybe a "depends on ..."

Or maybe CONFIG_SMP should enable some bits of the ACPI code needed to
detect such additional cores.

--
Miguel Ojeda
http://maxextreme.googlepages.com/index.htm
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