JNA fails to load ?

[Yang]

I have jna-3.2.7 in the classpath, but at the start of server messages, I see:

INFO 17:48:12,321 Unable to link C library. Native methods will be disabled.
java.lang.UnsatisfiedLinkError: Error looking up function
'$$YJP$$mlockall': java: undefined symbol: $$YJP$$mlockall
        at com.sun.jna.Function.<init>(Function.java:179)
        at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:344)
        at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:324)
        at com.sun.jna.Native.register(Native.java:1341)
        at com.sun.jna.Native.register(Native.java:1018)
        at org.apache.cassandra.utils.CLibrary.<clinit>(CLibrary.java:57)
        at 
org.apache.cassandra.service.AbstractCassandraDaemon.setup(AbstractCassandraDaemon.java:118)
        at 
org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:330)


mlockall() seems to be just in libc.so, and I do have libc.so.6 in /lib/