* Read the local apic id of the current logical processor
@ 2011-01-20 13:19 Edwin Bennink
0 siblings, 0 replies; 2+ messages in thread
From: Edwin Bennink @ 2011-01-20 13:19 UTC (permalink / raw)
To: linux-acpi
Dear acpi list members,
I'm not sure if this is the correct place to post this question, but I'm
looking for a way to read the local apic id (not the initial one) of the
current logical processor in a simple user-space program.
According to the documentation I found, this local apic id is stored in
a memory mapped msr register. Unfortunately I could not find a way to
access this value from within user-space. All search results on the web
involved kernel code...
The purpose of getting this id is to determine the processor hierarchy
on a cluster; i.e. the number of logical processors, physical
processors, packages, and nodes. The initial apic id (the one cpuid
returns) is set by the bios and therefore it does not distinguish
between the nodes in a cluster.
Any other way to get some kind of node id for the current logical
processor makes me happy too :-)
Best,
Edwin
ps. I posted the same message in the linux-smp list earlier, but after
that I noticed that the list was dead...
^ permalink raw reply [flat|nested] 2+ messages in thread
* Read the local apic id of the current logical processor
@ 2011-01-20 10:38 Edwin Bennink
0 siblings, 0 replies; 2+ messages in thread
From: Edwin Bennink @ 2011-01-20 10:38 UTC (permalink / raw)
To: linux-smp
Dear smp list members,
I'm looking for a way to read the local apic id (not the initial one) of
the current logical processor in a simple user-space program.
According to the documentation I found, this local apic id is stored in
a memory mapped msr register. Unfortunately I could not find a way to
access this value from within user-space. All search results on the web
involved kernel code...
The purpose of getting this id is to determine the processor hierarchy
on a cluster; i.e. the number of logical processors, physical
processors, packages, and nodes. The initial apic id (the one cpuid
returns) is set by the bios and therefore it does not distinguish
between the nodes in a cluster.
Any other way to get some kind of node id for the current logical
processor makes me happy too :-)
Best,
Edwin
^ permalink raw reply [flat|nested] 2+ messages in thread
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