4 ms·
No it could not not have happened. Address space pressure was immense back in the day, and plain doubling the width of everything while retaining the compatabl
by lstodd 3y ago
No it could not not have happened.
Address space pressure was immense back in the day, and plain doubling the width of everything while retaining the compatablity was the obvious choice.
- aleph_minus_one 3y ago> Address space pressure was immense back in the day, and plain doubling the width of everything while retaining the compat[i]blity was the obvious choice. PAE (https://en.wikipedia.org/wiki/Physical_Address_Extension https://en.wikipedia.org/wiki/Physical_Address_Extension) existed for quite some time to enable x86-32 processors to access > 4 GiB of RAM. Thus, I would argue that if the OS provided some functionality to move allocated pages in and out of the 32 bit address space of a process to enable the process to use more than 4 GiB of memory is a much more obvious choice.
- acdha 3y agoPAE got some use - for that “each process gets 4GB” model you mentioned in Darwin and Linux - but it was slower and didn’t allow individual processes to easily use more than 2-3GB in practice.
- lstodd 3y ago> Thus, I would argue that if the OS provided some functionality to move allocated pages in and out of the 32 bit address space of a process to enable the process to use more than 4 GiB of memory ... Oh, no. Back then the segmented memory model was still remembered and no one wanted a return to that. PAE wasn't seen as anything but a bandaid. Everyone wanted big flat address space. And we got it. Because it was the obvious choice, and the silicon could support it, Intel or no.