Experiments with readahead profiling

Ubuntu comes with some readahead boot caching. This can supposedly be optimized by passing a special parameter to the kernel at boot time. The procedure is described over in the Ubuntu forums.

Here what my boot looks like with the /etc/readahead/boot that ships with Ubuntu.

Here's what it looks like after profiling.

And here's what it looks like with an empty /etc/readahead/boot.

As you can see, the boot speed between each of these is negligible. This may have to do with the nature of the SSD -- there's nothing to be gained by reading files from the drive in a particular sequence.