On Tue Mar 17, 2026 at 10:10 AM JST, John Hubbard wrote: > On 3/16/26 6:02 PM, Alexandre Courbot wrote: >> On Tue Mar 17, 2026 at 3:51 AM JST, John Hubbard wrote: >>> On 3/16/26 6:12 AM, Alexandre Courbot wrote: >>>> On Mon Mar 9, 2026 at 10:53 PM JST, Joel Fernandes wrote: >>> ... >>>> I'm a bit torn as to whether we should use a `u64` to conform with the C >>>> API, but doing so would mean we cannot use an `Alignment`... >>> >>> Alex, have you seen my Alignment patch [1], for that? It's sitting >>> around with only Miguel having responded, but seems like exactly >>> what you're talking about here. >> >> Not exactly - this patch provides a shortcut for creating an Alignment >> from a u64, but it doesn't allow to store alignments larger than 4GB on >> a 32-bit architecture since the value itself is still stored as a `usize`. >> >> But that's really a theoretical worry of mine anyway - nobody will ever >> work with buffers larger than 4GB on a 32-bit arch to begin with. > > Actually, in the CPU world, this claim was made early and often, but > turned out to be wildly wrong! That's why we have "high mem" in > linux-mm (a constant source of suffering for kernel devs). > > The 32-bit systems designer do not feel constrained to keep their > memory sizes below that which they can directly address. :)
Yet IIUC PAE still limits a single process to a 4GB address space (and `usize` is still 32-bit anyway), so hopefully we will be spared that pain. :)
