Kernel Sizes

Shak · 22 Oct 2002 at 23:48

Just out of curiosity how big is your current kernel in size?

My server's is:

Code:

root@lemming init.d # du -sch /boot/bzImage 
1.2M    /boot/bzImage
1.2M    total

This uses no modules at all.

My main machine's is:

Code:

bash-2.05a# du -sch /boot/bzImage 
1.5M    /boot/bzImage
1.5M    total

Uses these modules:

Code:

Module                  Size  Used by    Tainted: PF 
vmnet                  20000   6 
parport_pc             17032   0  (unused)
parport                17728   0  [parport_pc]
vmmon                  20500   0 
emu10k1                76544   1 
ac97_codec              9824   0  [emu10k1]
w83781d                19232   0 
eeprom                  3616   0 
i2c-proc                6368   0  [w83781d eeprom]
i2c-isa                 1284   0  (unused)
i2c-amd756              3812   0  (unused)
i2c-core               13376   0  [w83781d eeprom i2c-proc i2c-isa i2c-amd756]

My backup kernel is:

Code:

bash-2.05a# du -sch /boot/mjc.kernel 
1.2M    /boot/mjc.kernel
1.2M    total

Again, no modules!

Shak

Shak · 23 Oct 2002 at 07:54

Originally posted by Sp00n
Care to explain what all that means to a newb?

The kernel is the bit that includes the drivers for all the devices etc. If the kernel has no modules then all the drivers are included in the kernel. I just wanted to see how compact everyones kernel was.

Shak

Shak · 23 Oct 2002 at 09:13

Pixie: Ill be online tonight (*hopefully*) to give an assistance.

Altered Corpse: What the heck have you got compiled into that thing? Its not a PPC kernel is it? I heard the PPC kernels were huge.

Shak

Shak · 23 Oct 2002 at 13:18

Mpemba: do us a favourt and use

Code:

du -sch <file name>

Then it tells you in MB!

Shak

Shak · 23 Oct 2002 at 19:02

Originally posted by Altered Corpse
It's the standard Red Hat 8 x86 kernel.

I'll probably compile 2.4.19 of the kernel when i'm not feeling so tired.

Ah, that explains it, the Redhat ones have all sorts of rubbish compiled in, but thats what they need, to allow the support of the different hardware.

Shak

Shak · 24 Oct 2002 at 12:59

I think a smaller kernel does make Linux kernel operations a little faster, Im not sure though, can anyone confirm this?

Shak

Shak · 24 Oct 2002 at 13:20

Theres a difference there though, because of the optomisations applied by Gentoo.

Optomisations that are used are things like this:

Code:

# Pentium Pro/Pentium II/Pentium III+/Pentium 4/Athlon optimized (but binaries
# will run on any x86 system)
#CHOST="i686-pc-linux-gnu"
#CFLAGS="-mcpu=i686 -O3 -pipe"
#CXXFLAGS="-mcpu=i686 -O3 -pipe"

# Pentium Pro/Pentium II/Pentium III+/Pentium 4/Athlon exclusive (binaries
# will use the P6 instruction set and only run on P6+ systems)
CHOST="i686-pc-linux-gnu"
CFLAGS="-march=i686 -O3 -pipe"
CXXFLAGS="-march=i686 -O3 -pipe"

This would account for some of the speed difference.

Shak

Shak · 24 Oct 2002 at 13:35

I doubt they are applied by Redhat as sometimes the problem "Segmentation Fault" occurs, I'm pretty sure that RH doesnt want these errors and therefore doesnt add these options into the GCC config.

Shak

Shak · 26 Oct 2002 at 13:20

But Mr Sprockets sir, is that not a GCC 3.2 flag? I be running GCC 2.95.3.

I'll have to have a look at the GCC 3.2 flags for when I do my upgrade (over Xmas)

Shak

Shak · 27 Oct 2002 at 18:07

Originally posted by Nozzer
I believe Shak has written a How-To on it, a search for "kernel compile" under this forum should show it up.

http://forums.overclockers.co.uk/showthread.php?s=&threadid=928

There we go.

This post was brought to you by the power of search

We really need our stickies back

Shak

Shak · 28 Oct 2002 at 12:03

Originally posted by Lucifer
i kinda realised i have no idea what options to choose at make menuconfig

You need to look at the current configuration, that is the .config file in you're other kernel sources and choose the hardware that you have, if there is some hardware there that you dont have de-select it.

You need to know the hardware and then just select which bits you need

Shak

Shak · 28 Oct 2002 at 12:29

Originally posted by Lucifer
i'm doing a test run on my desktop maching before i attack the server, i just made educated guesses for most of the options, reading the help bits, lets see if it boots

Thats the way everyone does it on the first go I think mate,

If the kernel panics, then take a look where in the loading it does or where there is an error. That way you can tell what you got wrong

Shak

Shak · 28 Oct 2002 at 16:21

Even if you dont use any modules I believe its essential to run the make modules and make modules_install stages, this creates a document that tells the kernel exactly what it needs to look for in the modules.

Shak

Shak · 28 Oct 2002 at 17:03

I dont use any modules and I've solved that problem by re-doing me make modules and make_modules install and it fixed it, guess I must have been lucky

Shak

Shak · 28 Oct 2002 at 17:30

Originally posted by Baloo
make modules will just produce an empty file if I remember correctly. The kernel will complain if it cannot find the file, not if it doesn't have any modules in it.

I knew I was right

I'll make sure that you see that site this week mate, when I get my webserver sorted.

Shak

Shak · 28 Oct 2002 at 17:43

Originally posted by Baloo
Cool. You see the one I'm using at the moment?

http://www.linuxuk.org

Looks blooming ace sir, nice skin, you like PostNuke?

Shak

Shak · 28 Oct 2002 at 18:09

Mai me if you need mate, I'm always available to help with it

Shak