3 ms·
> The allocator can choose which part of the address space to fill. No it can not. The allocator can request which part of the address space to fill, and the O
by masklinn 3y ago
> The allocator can choose which part of the address space to fill.
No it can not. The allocator can request which part of the address space to fill, and the OS is completely free to ignore that request.
> It does not have to deal with "whatever the OS wants".
It absolutely does, the OS is ultimately who controls both the physical and virtual address spaces.
> Even if you have a 1:1 memory mapping, you can leave the applications that want small addresses at the start of memory.
Up until it’s all taken and then you can’t do that anymore.
- Dylan16807 3y ago> the OS is completely free to ignore that request I'm assuming an OS that isn't refusing to do things for no reason. Aren't you? If we're accounting for capricious refusal of program allocation requests, then 64-bit clean programs can't safely run either. > Up until it’s all taken Which is no worse than it was before you upgraded your RAM. Not that anyone is running big programs on systems without MMUs.
- masklinn 3y ago> I'm assuming an OS that isn't refusing to do things for no reason. > Aren't you? You are apparently assuming the OS would have no reason to refuse. I've seen DeRaadt cook, I'd rather not assume anything that's not guaranteed. And I especially wouldn't make up new modes of operations which don't exist for no justifiable reason.