On Tue, 22 Sep 2020 at 17:12, Nicolas Pitre <nico@xxxxxxxxxxx> wrote: > > On Tue, 22 Sep 2020, Ard Biesheuvel wrote: > > > By changing the patchable sequences and the patching logic to carry > > more bits of offset, we can improve this: 11 bits gives us 4 GiB >> 11 > > == 2 MiB granularity, and so you never waste more than that amount by > > rounding up the physical start of DRAM to the next multiple of 2 MiB. > > (Note that 2 MiB granularity guarantees that the linear mapping can be > > created efficiently, whereas less than 2 MiB may result in the linear > > mapping needing another level of page tables) > > That is IMHO the top argument for limiting it to 2 MiB. > It would be worth making this explicit in the commit log. > OK, I will merge this paragraph into the commit log.
