On Sat, May 14 2022 at 02:22, Kirill A. Shutemov wrote: > On Thu, May 12, 2022 at 03:36:31PM +0200, Thomas Gleixner wrote: >> On Wed, May 11 2022 at 05:27, Kirill A. Shutemov wrote: >> > LAM_U48 steals bits above 47-bit for tags and makes it impossible for >> > userspace to use full address space on 5-level paging machine. >> >> > Make these features mutually exclusive: whichever gets enabled first >> > blocks the othe one. >> >> So this patch prevents a mapping above 47bit when LAM48 is enabled, but >> I fail to spot how an already existing mapping above 47bit would prevent >> LAM48 from being enabled. >> >> Maybe I'm missing something which makes this magically mutually >> exclusive. > > It is in 09/10. See lam_u48_allowed() Sure, but that makes this changelog not any more correct.
