[TriLUG] Newbie: Kernel Question

[davis]

On Fri, Oct 17, 2003 at 09:14:25AM -0400, Jeff Bollinger wrote:
<stuff deleted> 
> Not trolling here, but I'm interested to know what some folks have done 
> in terms of customizing their stock kernels?  I've only built a few back 
> 
<stuff deleted> 
> function/hardware/configuration of their system, but what are some good 
> kernel success stories, and does anyone have any tips to generally 
> improve performance (I/O, proc, network or otherwise)?
> 
> 
<stuff deleted> 

I have always run custom kernels.  Why?

1.  General performance.  I prefer not to use modules unless a removable module 
is necessary.  However, even then there is debate if removable modules for reinitialization
is good.  Some people prefer reinitialization using the procfs i/f.  Is it a worthwhile 
performance enahancement by skipping the extra call to resolve a module?  
The extra overhead is probably not noticeable.  Is is a habit?  Possibly.

2.  Disk space.  Why use up disk space for modules which you don't use?  i.e. I don't 
have a 3com card, so why have all their modules on my disk?  Once again, its probably 
overkill with today's large drives.  Embedded boxes are different.  See next bullet.

3.  Just general tweaking.  I like my kernel to be as small as possible so it leaves
more memory for other things besides unused functions.  Also saves on disk space for the
kernel itself.  Does it matter?  Probably not. However, its a trivial task, so why not do it
if you have the time and are so inclined.  Now, if its a kernel for work.  ie. I'm doing
a porting job, device driver development, etc.  It helps with development.  It makes
for a smaller kernel to tftpboot, faster load with riscwatch ( a jtag debugger ), etc.

4.  Specific kernel mods for performance enhancement.  SMP for a SMP machine. 
Optimize for router and not host for firewalls. etc. Match the cpu architecture to the
specific platform.  ie. choose pentium III instead of generic i386 for intel platforms.

5.  Specific console enhancements. ie. different font, more columns/rows, etc.

6.  And the real reason - when you do uname, you get your name printed.  



-- 
Happy Trails	

John F. Davis
ABC #6334 1992 R100GSPD                    Durham, North Carolina
http://www.skink.net