[Crash-utility] the kmem get some errors

hi, When i use kmem command on a IA64 with RHEL5.1 as following, there are some errors. Anyone can explain it? crash> kmem -c kmem: cannot determine page cache size crash> kmem -C kmem: address_space page cache radix tree not supported crash> kmem -la kmem: active_list does not exist in this kernel crash> kmem -La kmem: active_list does not exist in this kernel crash> kmem -li kmem: inactive_list does not exist in this kernel crash> kmem -Li kmem: inactive_list does not exist in this kernel crash> kmem -P e0000001843760c0 <segmentation violation> Best Regards, yang