56bdf2dbc2
vm_map_insert(), the kmem_back() assumption about newly inserted entry might be broken due to interference of two factors. In the low memory condition, when vm_page_alloc() returns NULL, supplied map is unlocked. If another thread performs kmem_malloc() meantime, and its map entry is placed right next to our thread map entry in the map, both entries wire count is still 0 and entries are coalesced due to vm_map_simplify_entry(). Mark new entry with MAP_ENTRY_IN_TRANSITION to prevent coalesce. Fix some style issues, tighten the assertions to account for MAP_ENTRY_IN_TRANSITION state. Reported and tested by: pho Reviewed by: alc