num_possible_cpus() giving more than possible.

From: Steven Rostedt
Date: Fri Sep 26 2008 - 16:23:10 EST



Hi Mike,

Peter told me that I should report this to you. I have two socket
single core hyper threaded box (must be hell). Peter told me that the
num_possible_cpus() should return the number possible on this box. The
explanation of my box tells us it should be 4. But it in fact returns 8.

nr_cpu_ids also returns 8.

here's the /proc/cpuinfo:

processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Xeon(TM) CPU 2.80GHz
stepping : 1
cpu MHz : 2793.151
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 3
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
lm constant_tsc pebs bts nopl pni monitor ds_cpl cid cx16 xtpr
bogomips : 5586.30
clflush size : 64
cache_alignment : 128
address sizes : 36 bits physical, 48 bits virtual
power management:

processor : 1
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Xeon(TM) CPU 2.80GHz
stepping : 1
cpu MHz : 2793.151
cache size : 1024 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 1
apicid : 6
initial apicid : 6
fpu : yes
fpu_exception : yes
cpuid level : 3
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
lm constant_tsc pebs bts nopl pni monitor ds_cpl cid cx16 xtpr
bogomips : 5586.20
clflush size : 64
cache_alignment : 128
address sizes : 36 bits physical, 48 bits virtual
power management:

processor : 2
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Xeon(TM) CPU 2.80GHz
stepping : 1
cpu MHz : 2793.151
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 1
initial apicid : 1
fpu : yes
fpu_exception : yes
cpuid level : 3
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
lm constant_tsc pebs bts nopl pni monitor ds_cpl cid cx16 xtpr
bogomips : 5586.23
clflush size : 64
cache_alignment : 128
address sizes : 36 bits physical, 48 bits virtual
power management:

processor : 3
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Xeon(TM) CPU 2.80GHz
stepping : 1
cpu MHz : 2793.151
cache size : 1024 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 1
apicid : 7
initial apicid : 7
fpu : yes
fpu_exception : yes
cpuid level : 3
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
lm constant_tsc pebs bts nopl pni monitor ds_cpl cid cx16 xtpr
bogomips : 5586.27
clflush size : 64
cache_alignment : 128
address sizes : 36 bits physical, 48 bits virtual
power management:


Perhaps since my physical ids show 0 and 3, it thinks it can also have
a 1 and 2?

Thanks,

-- Steve



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/