3 ms·
That's incorrect, 2^48 bits = 262144GB actually.
by metrxqin 7y ago
That's incorrect, 2^48 bits = 262144GB actually.
- lifthrasiir 7y agoBut x86-64 divides the 48-bit address space into two halves, only one of which is available in the user mode.
- monocasa 7y agoTo be fair, there's nothing that says the higher half _has_ to be entirely kernel mode. Only that bits 63 through 48 have to be the same value. And Intel has a spec out for a PML5 page table, giving you 57 total virtual address bits.
- unilynx 7y agoThey forgot to mention the kernel gets the top half of the address space, leaving 2^47 for the process. And then it mostly adds up.