NGE_JLEN
#define NGE_MCLBYTES (NGE_JLEN - sizeof(u_int64_t))
#define NGE_RESID (NGE_JPAGESZ - (NGE_JLEN * NGE_JSLOTS) % NGE_JPAGESZ)
#define NGE_JMEM ((NGE_JLEN * NGE_JSLOTS) + NGE_RESID)