How to detect multi-core and/or HT-enabled CPUs in 2.4.x and 2.6.x kernels

[Martin Knoblauch <knobi@knobisoft.de>]

Hi, (please CC on replies, thanks)

 for the ganglia project (http://ganglia.sourceforge.net/) we are
trying to find a heuristics to determine the number of physical CPU
"cores" as opposed to virtual processors added by enabling HT. The
method should work on 2.4 and 2.6 kernels.

 So far it seems that looking at the "physical id", "core id" and "cpu
cores" of /proc/cpuinfo is the way to go.

 In 2.6 I would try to find the  distinct "physical id"s and  and sum
up the corresponding "cpu cores". The question is whether this would
work for 2.4 based systems.

 Does anybody recall when the "physical id", "core id" and "cpu cores"
were added to /proc/cpuinfo ?

Cheers
Martin

------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www:   http://www.knobisoft.de