MemoryError, can I use more?

[Anssi Saari]

"Diez B. Roggisch" <deets at nospam.web.de> writes:

> Am 13.02.10 17:18, schrieb Anssi Saari:
>> Nobody<nobody at nowhere.com>  writes:
>>
>>> A single process can't use much more than 2GiB of RAM without a 64-bit CPU
>>> and OS.
>>
>> That's not really true. Even Windows XP has the /3GB boot option to
>> allow 3 GiB per process. On PCs, free operating systems and server
>> Windows can use PAE to give access to full 4 GB per process.
>
> No, PAE can be used to access much more memory than 4GB - albeit
> through paging. AFAIK up to 2^36 Bytes.

That too. I admit, after checking, that you can't go above 3 GiB per
process even in server Windows. But for Linux there exists (or
existed, since it seems it hasn't been updated since 2004) a kernel
patch which provides a "4GB/4GB" address split. Kernel is in one
segment, userland in another and hence a process can access full 4GB.