Trying to turn on swap space is useless, because by default jamvm claims only 1MB for its maximum heap size (see the -X option for details), while (normally) Linux doesn't hit its swap space with that small amount of memory; that bus error has another cause (I run jamvm with 40MB heap space fine).
kind regards,
Jos
ps. it -Xmx, not -Xms (that's the stack size limit)