如何在32位支持pae的Linux应用程序中使用超过3 GB的程序?

PAE (Physical Address Extension) was introduced in CPUs back in 1994. This allows a 32-bit processor to access 64 GB of memory instead of 4 GB. Linux kernels offer support for this starting with 2.3.23. Assume I am booting one of these kernels, and want to write an application in C that will access more than 3 GB of memory (why 3 GB? ) was introduced