Matt Thomas <m...@3am-software.com> wrote: > > I've been wondering... > > Should pmap_kenter_pa overwrite an existing entry should it be operating > on an unmapped VA.
You mean already mapped VA? > I think that if you want to change a mapping, you > should do a pmap_kremove first. I tend to agree. I have not seen a need for such re-mapping (overwriting), but even if there is, it can be done efficiently by removing, entering and then calling pmap_update(). With the deferred update, that would result in a single TLB flush/invalidation. In x86 pmap, there is a printf() for overwriting case: http://nxr.netbsd.org/xref/src/sys/arch/x86/x86/pmap.c?r=1.181#1005 Having this converted to an assert might catch something interesting. -- Mindaugas
