From: Rob Landley <rob@landley.net>
Organization: Boundaries Unlimited
To: Adrian Bunk <adrian.bunk@movial.fi>
Subject: Re: [PATCH] console - Add configurable support for console charset translation
Date: Wed, 4 Jun 2008 12:51:42 -0500
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On Wednesday 04 June 2008 05:33:53 Adrian Bunk wrote:
> Does the linux-tiny approach of adding a kconfig variable for each 5kB
> of code actually make sense? I'm asking since an exploding amount of
> kconfig variables and their interdependencies have a not so small
> maintainance impact in the long term.

Complexity is a cost, you have to get good bang for the buck when you spend 
it.

> And I'm wondering whether it's the best approach for reaching
> measurable results.

When I first started stripping down systems to make embedded masquerading 
routers back in the late 90's (before linksys came out), I started with a Red 
Hat install and removed lots and lots of packages.  That's the approach we're 
taking today, and I can say from experience that it's not sustainable.

I then wandered to a Linux From Scratch approach, building a system that had 
nothing in it but what I wanted.  Starting from zero and adding stuff, rather 
than starting from Mt. Crapmore and removing things until the shovel broke.

Someday I want to do the same for the Linux kernel.  When I started building 
systems instead of carving them out of blocks of distro, I started with 
a "hello world" root filesystem, and I want to make a "hello world" kernel.  
Start with just the boot code that does the jump to C code, only instead of 
start_kernel() in init/main.c have it call a hello_world() function that 
prints "hello world" to the console using the early_printk logic, then calls 
HLT.  And does _nothing_else_.  Then add stuff back one chunk at a time, 
sstarting with memory management, then the scheduler and process stuff, then 
the vfs, and so on.  So I know what all the bits do, and how big and 
complicated they are.  And I can document the lot of it as I go.

Unfortunately, as a learning experience, I estimate this would take me about a 
year.  And I haven't got a spare year on me at the moment.  But it remains 
prominently on my todo list, if I decide to start another major project.  
(Maybe after I get a 1.0 release of FWL out.)

> My gut feeling is that the influence of this kind of linux-tiny patches
> is hardly noticably compared to the overall code size development, but
> if you have numbers that prove me wrong just point me to them and I'll
> stand corrected.

The whackamole approach is never going to turn Ubuntu into Damn Small Linux, 
and it ignores the needs of the people who don't want the /proc hairball but 
_do_ want a ps that works.

Rob
-- 
"One of my most productive days was throwing away 1000 lines of code."
  - Ken Thompson.
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