Messages in this thread | | | From | "Nakajima, Jun" <> | Subject | RE: How to get number of physical CPU in linux from user space? | Date | Fri, 25 Oct 2002 11:54:53 -0700 |
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Recent distributions or the AC tree has additional fields in /proc/cpu, which tell - physical package id - number of threads for each CPU.
Using this info, you should be able to detect it. The problem is that they are not using the same keywords. I'm asking them to make those fields consistent.
Thanks, Jun
-----Original Message----- From: chrisl@vmware.com [mailto:chrisl@vmware.com] Sent: Friday, October 25, 2002 11:20 AM To: Martin J. Bligh Cc: linux-kernel@vger.kernel.org Subject: Re: How to get number of physical CPU in linux from user space?
On Fri, Oct 25, 2002 at 01:27:00AM -0700, Martin J. Bligh wrote: > Define "physical CPU number" ;-) If you want to deteact which
I mean the number of cpu chip you can count on the mother board.
> ones are paired up, I believe that if all but the last bit > of the apicid is the same, they're siblings. You might have to > dig the apicid out of the bootlog if the cpuinfo stuff doesn't > tell you.
And you are right. Those apicid, after mask out the siblings, are put in phys_cpu_id[] array in kernel.
I think about look at bootlog too, but that is not a reliable way because bootlog might already been flush out after some time.
Cheers
Chris
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