Linux内核空闲循环 [英] Linux kernel idle loop

问题描述

在linux内核空闲循环，对于相当多的架构（SH，ARM，X86等。据我所知）是以下行：

Inside the linux kernel idle loop, for quite a few architectures (SH, ARM, X86 etc.. afaik) are the following lines:

if(cpuidle_idle_call())
    pm_idle();

我的疑问：

目前，至少对于ARM，默认pm_idle功能包括注射用水（等待中断）指令，但令人困惑的部分是，中断被禁止再与WFI指令后启用执行时，如何做一个CPU从WFI回来在线当中断被禁用？

At-least for ARM, The default pm_idle function consists of WFI (Wait for interrupt) instruction but the confusing part is, interrupts are disabled then and are enabled after the WFI instruction executes, How does a CPU get back online from WFI when interrupts were disabled ?

我试图寻找我在linux各种版本的答案，但相关code是不变的，因为2.6.32（最后的版本我提到），所以它更有可能的是，我失去了一些东西。

I tried searching for my answers in various versions of linux, but the related code is unchanged since 2.6.32 (the last version i referred to) so it's more likely that I am missing something.

推荐答案

WFI醒来即使中断被禁止，但直到中断被再次启用ARM内核不接收中断。

WFI wakes even if interrupts are disabled, but the ARM core doesn't receive the interrupts until interrupts are enabled again.

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