simple top-like I/O monitor (implemented in C)

 iotop-c does for I/O usage what top(1) does for CPU usage. It watches I/O
 usage information output by the Linux kernel and displays a table of
 current I/O usage by processes on the system. It is handy for answering
 the question "Why is the disk churning so much?".
 .
 iotop-c requires a Linux kernel built with the CONFIG_TASKSTATS,
 CONFIG_TASK_DELAY_ACCT, CONFIG_TASK_IO_ACCOUNTING and
 CONFIG_VM_EVENT_COUNTERS config options on.
 .
 iotop-c is an alternative re-implementation of iotop in C, optimized for
 performance. Normally a monitoring tool intended to be used on a system
 under heavy stress should use the least additional resources as
 possible.