atop

[John Johansen]

The server team has requested that the kernel team evaluate the inclusion
of atop into the kernel as it allows for better task accounting.

The kernel patches apply cleanly and have been built and have been lightly
tested on the Maverick kernel.  With some discussion of the patches at
https://lists.ubuntu.com/archives/kernel-team/2010-June/011307.html

The remaining question is whether the atop patches should be included.
There are a few concerns:

PATCH 2 modifies the process-accounting record, into a layout that is
incompatible with BSD v3 accounting.  I have looked around for what
requires BSD v3 accounting and found a few accounting projects like gnus
acct and elsa (http://elsa.sourceforge.net/),  But several other projects
like htop (requires /proc), iotop, latencytop do not seem to be using it
(though I didn't dive into the code to verify that).

It is possible to apply just the first patch and obtain some of the atop
functionality.

The other immediate concerns with the patches are: potential performance
regressions (none noticed in light testing), and just the general
hesitance to accept patches that are out of tree/not going upstream.

At this time I am unsure of the atop's projects planning for upstreaming
I have contacted them but at this time do not have a reply.  With a
quick search the last submission to LKML I can find is from 2008
http://marc.info/?l=linux-kernel&m=120716470803492&w=2
http://marc.info/?l=linux-kernel&m=120716470803498&w=2
http://marc.info/?l=linux-kernel&m=120716470803497&w=2