Kernel 2.6.23.12-linode37 includes BSD process accounting, latest 2.6 doesn't point to it yet so you will need to manually select this kernel.

Then simply rename /sbin/init to /sbin/init-real and /sbin/bootchartd
to /sbin/init. Line 223 of bootchartd would then change from:

   init="/sbin/init"

to:

   init="/sbin/init-real"

Also make sure to install the GNU accounting utilities and turn on the process accounting option on line 19 of bootchartd.conf.

What if I'm on the Xen machine? These kernels setup for it?

Edit: Didn't seem to work, got no logfile :-/

Edit2: Had to do more file and script munging, still can't get it to stop after bootup is completed, so probably can't get a too accurate graph going this route.

Oh well, not that important.