Baslinux mailing list

[James Miller <jamtat AT mailsnare.net>]

Item from the Ottawa Linux Symposium now going on in, of all places,
Ottawa.

Tiny is better

Later in the morning, Matt Mackall talked about the Linux-Tiny project.

Linux-Tiny is a project to reduce the size of the Linux kernel and its
footprint -- or size -- in memory, for use on older legacy hardware, or
embedded systems.

Mackall explained that the Linux kernel has become bloated over the last
ten years and has a lot of room to shrink. He explained very rationally
how this came to pass.

Linux kernel hackers got jobs.

In 1994 the kernel was at version 0.99 and could happily run on a 486 SX
running at 16MHz with 4 MB of RAM.

By this year, 2004, the kernel had arrived at version 2.6 and could
happily run on a 1024 node Intel 64 bit (ia64) architecture cluster with
multiple terabytes of RAM.

When Linus got his job at Transmeta, he was suddenly entrusted with a
computer running with 512M of RAM and various other improved features over
the older hardware he had been developing Linux on. Memory use and disk
use become less of a priority, and functionality and features took the
forefront.

Over the period of 1994 to 2004 there was a huge growth in personal
computing and Internet use, and a constant massive reduction in hardware
costs. Coupled with Moore's law of ever accelerating hardware, this led to
the loss of the concept of running Linux on small, old systems.

Linux has grown, Mackall went on, one small change at a time. Eventually
lots of small changes adds up to large changes, significant improvements
in various performances, and increased size.

Mackall's project, Linux-Tiny, aims to reverse this trend. He noted that
it was nice to be scaling in the opposite direction for a change.

The means Linux-Tiny uses to get to its small memory footprint and kernel
image size ends is a radical trimming down of the kernel's... less
necessary features.

Mackall described the various steps he took to reduce the kernel's size by
removing extraneous code, wasted memory, and unneeded text output. His
stated goal was to run a small Linux system whose sole purpose in life was
to run a web server with no bloat.

He has so far reduced the kernel to a 363 KB image, significantly below
the 1.9 MB image found in a default compile of kernel 2.6.5, and
comparable to the 1994 kernel 0.99pl15 image size in Slackware 1.1.2 of
just 301 KB. His memory consumption is down to less than 2 MB, and
together this means that Linux-Tiny can run on embedded systems and legacy
hardware efficiently, as it did before Linux kernel hackers got jobs.