Systemtap

Install Systemtap.  You will need to kernel-debuginfo, kernel-devel and kernel-headers first
#yum install kernel-debuginfo-$(uname -r) kernel-devel-$(uname -r) kernel-headers-$(uname -r)

If the machine is a production server then only install the runtime
#yum install systemtap-runtime
ELSE
#yum install systemtap

Check the following examples
#ll /usr/share/doc/systemtap-1.1/examples
drwxr-xr-x 2 root root  4096 Jan 30 15:52 general
drwxr-xr-x 2 root root  4096 Jan 30 15:52 html
-rw-r--r-- 1 root root 31140 Nov 17 14:41 index.html
-rw-r--r-- 1 root root 21938 Nov 17 14:41 index.txt
drwxr-xr-x 2 root root  4096 Jan 30 15:52 interrupt
drwxr-xr-x 2 root root  4096 Jan 30 15:52 io
-rw-r--r-- 1 root root 63347 Nov 17 14:41 keyword-index.html
-rw-r--r-- 1 root root 41966 Nov 17 14:41 keyword-index.txt
drwxr-xr-x 2 root root  4096 Jan 30 15:52 locks
drwxr-xr-x 2 root root  4096 Jan 30 15:52 memory
drwxr-xr-x 2 root root  4096 Jan 30 15:52 network
drwxr-xr-x 2 root root  4096 Jan 30 15:52 process
drwxr-xr-x 2 root root  4096 Jan 30 15:52 profiling
-rw-r--r-- 1 root root  5065 Nov 17 14:41 README
It is possible to create modules which can be run using staprun
#stap iotop.stp -m iotop

will create  iotop.ko. This can be run with the following command

#staprun iotop.ko