Re: Slow ifconfig

[Mirek Kwasniak <mirek@zind.ikem.pwr.wroc.pl>]

On Tue, Oct 13, 1998 at 06:27:30PM +0000, Rene Hojbjerg Larsen wrote:
> Somehow my ifconfig has become extremely slow.  I'm not sure exactly when
> this happened, but it probably happened while upgrading to slink the other
> day.
> 
> To give an example:
> 
> $ time /sbin/ifconfig >/dev/null
> 
> real    0m6.788s
> user    0m4.450s
> sys     0m1.590s
> 
> This used to take far less than a second...
> 
> If I strace the ifconfig process, it pauses around these lines:
> 
> socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 3
> socket(PF_IPX, SOCK_DGRAM, [PF_UNSPEC]) = -1 ENOSYS (Function not

[...]

> 
> Specifically, it pauses for about two seconds before (in?) the third
> socket call for each protocol (IPX, AX25, APPLETALK).  My kernel is
> compiled without support for any of these, and I have aliasesed them to
> "off" in /etc/conf.modules.  This happens with both kernels 2.0.36pre14
> and 2.1.125.  The version of netbase installed is 3.11-1.
> 
> Unless one of you has a solution, I will post a bug report.

I checked kerneld tries load modules or reread conf file many times
executing modprobe and command from config like this:

   path[*]=/lib/modules/`uname -r`
   path[*]=/lib/modules/`kernelversion`

On my station invocation of ifconfig execute about 160 processes:

>  22:06:59 3:2'kwasniak@mirek~$ ifconfig >/dev/null;ps tp3
>    PID TTY STAT TIME COMMAND
>  15329  p3 S    0:00 /bin/bash
>  22506  p3 R    0:00 ps tp3
>  22:09:58 3:2'kwasniak@mirek~$ ifconfig >/dev/null;ps tp3
>    PID TTY STAT TIME COMMAND
>  15329  p3 S    0:00 /bin/bash
>  22672  p3 R    0:00 ps tp3

22672-22506 = 166 !!!!!!!!

Bug should be posted against modutils:

$ time ifconfig
real    0m4.923s  :(
user    0m0.020s
sys     0m0.000s
$ killall kerneld  !!!!
$ time ifconfig
real    0m0.034s  :)
user    0m0.010s
sys     0m0.000s


Mirek