The pmap_remove function removes the range of addresses between sva and eva from the physical map pmap. If eva is less than sva, then the result is undefined. It is assumed that both sva and eva are page-aligned addresses.
The pmap_remove_all removes the physical page m from all physical maps in which it resides, and reflects back the modify bits to the appropriate pager.
The pmap_remove_pages function removes all pages from the physical map pmap, within the range of physical addresses bounded by sva and eva. This function is called when a process exits to run down its address space more quickly than would be the case for calling pmap_remove.