Each page table entry has a byte associated with it that stores the key, as well as the referenced and changed bits.
And yes, 4K page tables do soak up lots of memory, which is why later OSes use 1M or 2M pages. On Tue, Nov 22, 2022 at 9:22 AM Ian Worthington < [email protected]> wrote: > Does anyone know where the storage protection keys are kept? It seems > that the processors maintain recent keys in the TLB to be accessed by the > DAT, but where do they live when they're not in the TLB? Surely we need > one byte per 4k page per address space, which could be quite a bit of > storage, so I'm assuming this has to be above the bar now? I can't see any > information in the pop about this. > > > Best wishes / Mejores deseos / Meilleurs vœux > > Ian ... > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > -- Jay Maynard ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
