P_MIGRATE
#define PP_ISMIGRATE(pp) ((pp)->p_state & P_MIGRATE)
#define PP_SETFREE(pp) ((pp)->p_state = ((pp)->p_state & ~P_MIGRATE) \
#define PP_SETMIGRATE(pp) ((pp)->p_state |= P_MIGRATE)
#define PP_CLRMIGRATE(pp) ((pp)->p_state &= ~P_MIGRATE)