On Tue, Oct 29, 2024 at 11:18:29PM +0000, Luck, Tony wrote: > >> Yeah, I was talking about 64-bit only. On 32-bit PAE a PGD maps 1/4 of > >> the address space which is totally unworkable for stealing. > > > > But it is also not necessary. > > So maybe we could make the 64-bit version of use_temporary_mm() > use some reserved address mapping to a reserved PGD in the upper > half of address space, and the 32-bit version continue to use "user" > addresses. It's unclear to me whether adding complexity here would be > worth it to remove the 64-bit STAC/CLAC text patching issues. Redesigning use_temporary_mm() is an interesting experiment, but it is out of scope for the series. LASS blocks LAM enabling. It would be nice to get LAM re-enabled soonish. Maybe we can look at use_temporary_mm() again after LASS gets upstream? -- Kiryl Shutsemau / Kirill A. Shutemov
