nlmon - netlink based task monitor
-----------------------------------

Features:
- netlink based (lower overhead compared to procfs based tools, complete accounting over also for short-lived threads)
- thread reporting only
- output modes: text, csv, ncurses
- reports: cputimes, iotimes, RSS, cpudelay, iodelay

Required kernel configuration options:
CONFIG_CONNECTOR
CONFIG_PROC_EVENTS
CONFIG_TASKSTATS
CONFIG_TASK_DELAY_ACCT
CONFIG_TASK_XACCT
CONFIG_TASK_IO_ACCOUNTING

Not supported features:
- CPU hotplug and freqency changing


CPU data
=========

Fetched from procfs, see Documentation/filesystems/proc.txt

  > cat /proc/stat
  cpu  2255 34 2290 22625563 6290 127 456 0 0
  cpu0 1132 34 1441 11311718 3675 127 438 0 0
  cpu1 1123 0 849 11313845 2614 0 18 0 0
  intr 114930548 113199788 3 0 5 263 0 4 [... lots more numbers ...]
  ctxt 1990473
  btime 1062191376
  processes 2915
  procs_running 1
  procs_blocked 0
  softirq 183433 0 21755 12 39 1137 231 21459 2263

The very first  "cpu" line aggregates the  numbers in all  of the other "cpuN"
lines.  These numbers identify the amount of time the CPU has spent performing
different kinds of work.  Time units are in USER_HZ (typically hundredths of a
second).  The meanings of the columns are as follows, from left to right:

- user: normal processes executing in user mode
- nice: niced processes executing in user mode
- system: processes executing in kernel mode
- idle: twiddling thumbs
- iowait: waiting for I/O to complete
- irq: servicing interrupts
- softirq: servicing softirqs
- steal: involuntary wait
- guest: running a normal guest
- guest_nice: running a niced guest

Thread data
============

TBD.


License
========

GPLv2, see file LICENSE.


Running as non-root
===================

One option is to make the binary setuid but be aware that this also requires the binary to belong to root.
In other words only setting the setuid bit is not sufficient.