基本概念理解:win32进程可以管理多少内存?

wooyz 2008-06-14 03:19:01
加精
从MSDN上看到,PAE和AWE的相关资料。
感觉看得不是很明白。

疑问:
1。按照下文所述,如果不是Windows Server 2003 Enterprise Edition Windows Advanced Server, Limited Edition
Windows 2000 Datacenter Server ,Windows 2000 Advanced Server 则无法使用PAE功能,那么是否意味着应用程序最大只能访问4GB的物理内存?
2。下文中,memory和physical memory究竟指的是什么概念?
3。按照下文所述,对于AWE,如果不支持PAE,则AWE无法预留大于4GB的物理内存。假设在没有使能PAE的情况下,物理内存有8GB,那么对于一个进程来说,该进程最大可以预留多少物理内存呢?4GB?该进程最大可以使用的内存有多少呢?4GB(扩展)+2GB(工作区)?

望各位大牛斧正!



附录:从MSDN摘取

Physical Address Extension
The Physical Address Extension (PAE) enables applications to address more than 4 GB of physical memory. It is supported by Intel processors. The following systems can use PAE to take advantage of physical memory beyond 4 GB:



Windows Server 2003 Enterprise Edition
Windows Advanced Server, Limited Edition
Windows 2000 Datacenter Server
Windows 2000 Advanced Server
To enable PAE, you must use the /PAE switch in the Boot.ini file.

With PAE enabled, the operating system moves from two-level linear address translation to three-level address translation. The extra layer of translation provides access to physical memory beyond 4 GB. Instead of a linear address being split into three separate fields for indexing into memory tables, it is split into four separate fields; a 2-bit field, two 9-bit fields, and a 12-bit field that corresponds to the page size implemented by Intel Architecture (4 KB).

Typically, a process can access up to 2 GB of memory address space (assuming the /3GB switch was not used), with some of the memory being physical memory and some being virtual memory. The memory manager uses PAE to provide more physical memory to an application, which reduces the need to swap memory to the page file and increases performance. The application itself is not aware of the actual memory size. All of the memory management and allocation of the PAE memory is handled by the memory manager independently of the application.

Applications that are 4GT-aware are likely to remain in physical memory rather than be paged out, which increases their performance. The exception is when the /3GB switch is used in conjunction with the /PAE switch. In this case, the operating system does not use any memory in excess of 16 GB. Therefore, if the system restarts with the /3GB entry in the Boot.ini file, and the system has more than 16 GB of physical memory, the additional physical random access memory (RAM) is not used by the operating system. Restarting the computer without the /3GB switch enables the use of all of the physical memory.

Address Windowing Extensions (AWE) enables applications to address more than 4 GB. AWE enables an application to reserve physical memory as nonpaged memory, then dynamically map portions of the nonpaged memory to its working set. This enables memory-intensive programs to reserve large amounts of physical memory for data without swapping to disk. Instead, the data is swapped between the working set and reserved memory above the 4 GB range. The memory above 4 GB is exposed to the memory manager and the AWE functions by PAE. Without PAE, AWE is unable to reserve memory in excess of 4 GB.
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btkxql 2012-06-25
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一个是物理内存:2的数据线次幂;一个是虚拟内存,WINDOWS下是4G的虚拟内存空间。其中还有些是系统的,一些是给应用程序的。
dianyancao 2011-05-08
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真菌無處不在
kmzwyong12 2010-11-21
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都是高手,初来乍到,学习学习。
jianw2 2010-11-16
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楼主的文章是哪里的?谁可以翻译下?
WEIYU20062871 2010-11-01
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路过,加学习!
mrjinle 2010-01-22
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都是高手,初来乍到,学习学习。
bzf12 2008-09-12
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学习 很好啊
沙漠里的海豚 2008-07-09
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学习一下 呵呵
red_berries 2008-07-04
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mark下
KeSummer 2008-07-04
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PAE的功能是32 bit intel 奔腾系列系列 cpu的功能(当然后来追上的AMD也支持了).工作于PAE模式下32条地址线的功能是不同的。

另外根据官方(MS)的说明,32 bit xp下见不到4GB物理内存是因为主板,RAM等会占用一部分作为页冗余。
lance 2008-07-04
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从奔腾 开始,外部数据总线就是64根了。从奔腾pro开始,地址线就是36根了。
caosdn 2008-06-26
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取决于你的主板芯片组,安装的设备等等,总之32位系统是看不到4G的。如果是64位操作系统可能还能看到,不过也要看你的芯片组是否支持了。
域樹臨風 2008-06-24
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路过,学习
qinglisheng 2008-06-23
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引用 39 楼 hjyhh 的回复:
学习~~~~~~~~~~~~~~~
brave_zm 2008-06-23
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[Quote=引用 39 楼 hjyhh 的回复:]
学习~~~~~~~~~~~~~~~
[/Quote]
yrnaaa 2008-06-22
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回帖是一种美德!
DDDDD
hjyhh 2008-06-21
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学习~~~~~~~~~~~~~~~
jwh5566 2008-06-21
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学习下.....................
cppwizard_alvin 2008-06-20
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。。。。。。。。。。。。。。。。。。。。。。。。。。。。
yjf79 2008-06-19
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好 学习了 谢谢楼主的帖子
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