程序是否连续使用逻辑地址? [英] Does a program use logical address in a continuous manner?

问题描述

程序是否始终以连续方式使用逻辑地址?程序是否可能不使用0-200逻辑地址，而是使用随机地址?

Does a program always use logical address in a continuous manner? Is it possible that a program does not use 0-200 logical addresses and instead use random addresses?

我之所以这样问是因为，当我在阅读有关操作系统中的内存管理的内容时 高尔文的概念 作者提到页面表为每个页面存储一个条目，无论该页面是有效还是无效.

I am asking this because while I was reading about memory management in Operating system concepts by Galvin, the author mentioned that the page table stores an entry for each page no matter whether the page is valid or invalid.

如果页面被连续使用，那么我们将不需要存储所有条目.

If the pages were used continuously then we would not need to store all entries.

推荐答案

逻辑地址空间中的验证地址范围始终是不连续的.

The validate address range in a logical address space is invariably discontinuous.

首先，用户空间和系统空间有一个单独的地址范围.系统空间通常位于较高的地址范围，而用户空间通常起始于较低的地址范围.

To start with, there is a separate range of addresses for the user space and the system space. The system space is usually at a high range of addresses while the user space usually starts at a low range of addresses.

即使用户空间也往往是不连续的.应用程序数据倾向于从低端开始，而堆栈空间(向下增长)则倾向于在较高地址处.

Even the user space tends to be discontinuous. Application data tends to start at the low end and stack space (which grows downward) tends to be at higher addresses.

作者提到页面表为每个页面存储一个条目，无论该页面是有效还是无效.

the author mentioned that the page table stores an entry for each page no matter whether the page is valid or invalid.

那根本不对.

在具有线性页表的系统中，通常可以通过系统参数设置页表的最大大小，并通过进程配额来减小页表的最大大小.可能有逻辑地址，根本没有页面表条目.

In systems with linear page tables, there is a maximum size of the page table that usually can be set by system parameters and reduced by process quotas. There are likely to be logical addresses with no page table entry at all.

在具有多级页表的系统中，由于缺少页表而导致逻辑地址空间中的空白.

In systems with multilevel page tables, there can be gaps in the logical address space caused by missing page tables.

这篇关于程序是否连续使用逻辑地址?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！