Re: Make ipconfig.c work as a loadable module.

On Fri, Mar 07, 2003 at 01:29:05AM +0000, Chris Dukes wrote:

If IBM can fit a kernel and a ramdisk containing all the utilities you
describe and more in smaller than 5M of file for tftp, one would think 
that it could be done on Linux.

Wow.  5MB eh?  We currently do NFS-root in 690K.

quoted

ipconfig.c does more than just configure networking.  It's a far smaller
solution to NFS-root than any userspace implementation could ever hope
to be.

That's nice.  Would you mind explaining to us where that would be a
benefit?  Aside from dead header space in elf executables, I'm at
a loss as to how a usermode implementation must be significantly
larger than kernel code.

If you're suggesting above that "5MB isn't significantly larger than
the size Linux can do this" then I think I've just proven you wrong.

Lets see - building an ramdisk to mount a root filesystem out of existing
binaries would require from my exisitng systems probably something like:

   text    data     bss     dec     hex filename
1093047   21224   15560 1129831  113d67 /lib/libc.so.6
 515890   22320   16640  554850   87762 /bin/sh
  58540    2436    9776   70752   11460 /lib/libresolv.so.2
  53685    1476    5488   60649    ece9 /bin/mount
  45511     672     432   46615    b617 /bin/sed
  42830     624      40   43494    a9e6 /sbin/pump
  10783     500     104   11387    2c7b /lib/libtermcap.so.2
   8765     444      28    9237    2415 /lib/libdl.so.2

pump isn't really suitable for the task, but I don't have dhcpcd around.
dhcpcd is even larger than pump however.

That's getting on for 2MB vs:

   2620    2012       0    4632    1218 fs/nfs/nfsroot.o
   8016     380      80    8476    211c net/ipv4/ipconfig.o

about 13K.

Which version is overly bloated?
Which version is huge?
Which version is compact?

Even the klibc ipconfig version is significantly larger than the in-kernel
version - and klibc and its binaries are written to be small.



Note: I *do* agree that ipconfig.c needs to die before 2.6 but I do not
agree that today is the right day.

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html