Linux 可以使用它不应该（？）看到的内存（RAM）
Linux can use memory (RAM) which it should not (?) see
我有一个关于 GNU/Linux 的问题。我的笔记本电脑有 6GB 内存，我在上面安装了 Linux Mint 17.2 x86。据我所知，32 位操作系统只能处理 4 GB，但 Linux Mint 报告说它可以使用全部 6 GB。
这怎么可能？
Physical Address Extension (PAE), sometimes referred to as Page Address Extension, is a memory management feature for the IA-32 architecture. PAE was first introduced in the Pentium Pro. It defines a page table hierarchy of three levels, with table entries of 64 bits each instead of 32, allowing these CPUs to access a physical address space larger than 4 gigabytes (23^2 bytes).
(c) https://en.wikipedia.org/wiki/Physical_Address_Extension
Physical Address Extension (PAE) is a feature found on almost all 32
bit processors produced after Pentium Pro, ie. younger than around
1995. Because PAE is close to being a standard it is now a requirement for Ubuntu: During installation the processor is prompted for the PAE
flag, and only if present the process will carry on.
Lubuntu and Xubuntu offered a PAE and a non-PAE release up to and
including 12.04, but from 12.10 only the PAE releases are maintained.
我有一个关于 GNU/Linux 的问题。我的笔记本电脑有 6GB 内存，我在上面安装了 Linux Mint 17.2 x86。据我所知，32 位操作系统只能处理 4 GB，但 Linux Mint 报告说它可以使用全部 6 GB。
这怎么可能？
Physical Address Extension (PAE), sometimes referred to as Page Address Extension, is a memory management feature for the IA-32 architecture. PAE was first introduced in the Pentium Pro. It defines a page table hierarchy of three levels, with table entries of 64 bits each instead of 32, allowing these CPUs to access a physical address space larger than 4 gigabytes (23^2 bytes).
(c) https://en.wikipedia.org/wiki/Physical_Address_Extension
Physical Address Extension (PAE) is a feature found on almost all 32 bit processors produced after Pentium Pro, ie. younger than around 1995. Because PAE is close to being a standard it is now a requirement for Ubuntu: During installation the processor is prompted for the PAE flag, and only if present the process will carry on.
Lubuntu and Xubuntu offered a PAE and a non-PAE release up to and including 12.04, but from 12.10 only the PAE releases are maintained.