On Thu, Oct 24, 2002 at 04:02:29PM -0700, chrisl@vmware.com wrote:
> It seems that /proc/cpuinfo will return the number of logical CPU.
> If the machine has Intel Hyper-Thread enabled, that number is bigger
> than physical CPU number. Usually twice as big.
>
> My question is, what is the reliable way for user space program
> to detect the number of physical CPU in the current machine?
>
> If in it is in the kernel, I can read from cpu_sibling_map[]
> or phys_cpu_id[]. But it seems not easy read that from
> user space.
>
> Of course I can do "gdb /proc/kcore" to get them. But is there
> any better way?
You can perform cpuid instructions in userspace to get the
number of siblings per physical package.
-- | Dave Jones. http://www.codemonkey.org.uk - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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