一切都在标题中.欢迎任何指向良好文件的链接.
最佳答案
本地定时器中断是在APIC上实现的定时器,它仅中断特定CPU,而不是引发可由任何CPU处理的中断.它在Bovet& amp; Cesati的“了解Linux内核”.一个片段:
The local APIC present in recent 80×86 microprocessors (see the
section “Interrupts and Exceptions” in Chapter 4) provides yet another
time-measuring device: the CPU local timer.The CPU local timer is a device similar to the Programmable Interval
Timer just described that can issue one-shot or periodic interrupts.
There are,however,a few differences:
- The APIC’s timer counter is 32 bits long,while the PIT’s timer counter is 16 bits long; therefore,the local timer can be programmed
to issue interrupts at very low frequencies (the counter stores the
number of ticks that must elapse before the interrupt is issued).- The local APIC timer sends an interrupt only to its processor,while the PIT raises a global interrupt,which may be handled by any
CPU in the system.- The APIC’s timer is based on the bus clock signal (or the APIC bus signal,in older machines). It can be programmed in such a way to
decrease the timer counter every 1,2,4,8,16,32,64,or 128 bus
clock signals. Conversely,the PIT,which makes use of its own clock
signals,can be programmed in a more flexible way.
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。