是否有一个`x86`指令告诉指令正在运行在哪个核心？

问题描述：

当我执行cat / proc内/ cpuinfo ，我看到8个内核，用的ID从 0 到 7 。

When I cat /proc/cpuinfo, I see 8 cores, with ID's from 0 to 7.

有一个 86 指令，将报告该指令本身运行的核心中的核心ID？

Is there an x86 instruction that will report the core id of the core that the instruction itself is running on?

我看了看 CPUID 但这似乎并没有返回 COREID 下的任何参数设置。

I looked at cpuid but that does not seem to return coreid under any parameter setting.

答

的英特尔®64和IA-32架构软件开发人员手册卷3A：系统编程指南，第1部分的，部分的 8.4.5确定逻辑处理器在MP系统的名单，其中包括：

The Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 3A: System Programming Guide, Part 1, section 8.4.5 Identifying Logical Processors in an MP System lists, among others:

这APIC ID由CPUID.0BH报道：EDX [31：0]

This APIC ID is reported by CPUID.0BH:EDX[31:0]

请注意，这并不直接等同于linux内核的编号。在内核中有，你可以阅读 x86_cpu_to_apicid 表。当然，内核也知道code正在执行什么CPU，而不必咨询APIC：

Note that this doesn't directly equate to the linux kernel's numbering. In the kernel there is an x86_cpu_to_apicid table that you can read. Of course the kernel also knows what cpu the code is executing on, without having to consult the APIC:

 * smp_processor_id(): get the current CPU ID.
 *
 * if DEBUG_PREEMPT is enabled then we check whether it is
 * used in a preemption-safe way. (smp_processor_id() is safe
 * if it's used in a preemption-off critical section, or in
 * a thread that is bound to the current CPU.)

是否有一个`x86`指令告诉指令正在运行在哪个核心？

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