RES保持增长，但没有通过jstat显示的GC？

我们有一个在Centos 6.4上运行的Java应用程序，我们注意到RES值是跨越400m，这是超过256m的最大堆。 根据jstat的结果如下，没有GC发生这种令人震惊的情况？ 可以采取什么积极的措施我也通过MAT运行堆分析。

Timestamp S0 S1 EOP YGC YGCT FGC FGCT GCT 2331438.3 56.95 0.00 62.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331443.3 56.95 0.00 62.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331448.4 56.95 0.00 62.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331453.4 56.95 0.00 62.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331458.4 56.95 0.00 62.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331463.4 56.95 0.00 62.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331468.4 56.95 0.00 62.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331473.4 56.95 0.00 63.24 82.79 80.37 1362 54.337 0 0.000 54.337 2331478.4 56.95 0.00 63.24 82.79 80.37 1362 54.337 0 0.000 54.337 2331483.4 56.95 0.00 63.78 82.79 80.37 1362 54.337 0 0.000 54.337 2331488.4 56.95 0.00 63.78 82.79 80.37 1362 54.337 0 0.000 54.337 2331493.4 56.95 0.00 63.79 82.79 80.37 1362 54.337 0 0.000 54.337 2331498.4 56.95 0.00 63.79 82.79 80.37 1362 54.337 0 0.000 54.337 MAT results. Problem Suspect 1 One instance of "org.jboss.netty.channel.socket.oio.OioWorker" loaded by "org.rzo.yajsw.boot.WrapperClassLoader @ 0xf0002a50" occupies 49,451,672 (75.12%) bytes. Keywords org.rzo.yajsw.boot.WrapperClassLoader @ 0xf0002a50 org.jboss.netty.channel.socket.oio.OioWorker Problem Suspect 2 The class "java.lang.ref.Finalizer", loaded by "<system class loader>", occupies 10,408,112 (15.81%) bytes. Keywords java.lang.ref.Finalizer