the very rare case of shared mappings that have amap's attached in a
reasonable way -- this is not currently causing any problems, but i
fixed it anyway. update the comment in this section of code and also
be smarter about avoiding needless calls to pmap_protect().
the history buffers are "struct uvm_history_ent" to ensure proper
alignment (eg, alpha). this fixes a boottime panic when the pdhist was
used before it had been initialised.
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.
this is the UVM kernel code portion.
this will be KNF'd shortly. :-)