I believe enable systemtap will be very helpful for debugging.But I encountered belowing  error when enable systemtap support:

emantic error: probe point mismatch at position 0 (alternatives: __nfs __scheduler __signal __tcpmib __vm _linuxmib _signal _sunrpc _syscall _vfs begin begin(number) end end(number) error error(number) generic ioblock ioblock_trace ioscheduler ioscheduler_trace ipmib irq_handler kernel kprobe kprocess linuxmib module(string) nd_syscall netdev never nfs nfsd perf process process(number) process(string) procfs procfs(string) scheduler scsi signal socket softirq stap staprun sunrpc syscall tcp tcpmib timer tty udp vfs vm workqueue): identifier 'libvirt' at :130:7 while resolving probe point libvirt.event_poll.run
        source: probe libvirt.event_poll.run {
                      ^
Pass 2: analysis failed.  Try again with another '--vp 01' option.

Here's my environment:
    Ubuntu 11.04 amd64
    configured --with-dtrace --enable-shared=no --with-pic(fPIC flag also tried)
    dtrace installed and compile probe with dtrace -64

Would somebody pls give me some advice with this systemtap issue?
Thanks a lot!