_pt_top_set
_pt_top_set(NULL, PT_MAX_TOP_LEVEL));
table_alloc_top(common, _pt_top_set(NULL, pts.level),
new_top_of_table = _pt_top_set(pts.table, pts.level);
WRITE_ONCE(common->top_of_table, _pt_top_set(table_mem, top_level));