it in the last chunk (phys_avail block). The last chunk very often is
not larger than one or two pages, resulting in a msgbuf that's too
small to hold a complete verbose boot.
Note that pmap_steal_memory() will bzero the memory it "allocates".
Consequently, ia64 will never preserve previous msgbufs. This is not
a noticable difference in practice. If the msgbuf could be reused,
it was invariably too small to have anything preserved anyway.
f02e8e8122