[CentOS] kswapd taking 100% cpu with no swap on system

Hi All

I have xeon server with 16 Gb Ram and no Swap memory.I am running 
cassandra server on two node in cluster.When there is high load on 
server kswapd0 kicks inn and take 100% cpu and make machine very slow 
and we need to restart out cassandra server.I have  latest kernel 
2.6.18-238.9.1.el5.Please let me know how can i fix this issue .Its 
hurting us badly this our production server any quick help will be 
appreciated.

-- 
S.Ali Ahsan