Bug#407757: xen kernel makes dom0 slower, more information

["Heiko Schulz" <heiko@mathematik.uni-stuttgart.de>]

Hi,

I made the same test on a 32 bit K7 (Athlon 2400+) system: Xen works
very well. My stupid test script (see below) needs with

- the debian kernel 2.6.18-3-k7 1m9.938s
- the xen kernel 2.6.18-3-xen-k7, but without libc6-xen (stupid, I know)
  1m34.722s,
- the xen kernel 2.6.18-3-xen-k7 and with libc6-xen 1m9.681s.

I observed that the performance with 2.6.18-3-xen-amd64 on the Xeon dual
core machines is similar bad like 2.6.18-3-xen-k7 without libc6-xen - but
where is no tls on 64 bit machines...

Here is the absolutely stupid test script

#!/bin/bash

i=0

while [ $i != $1 ]
do
  i=$((i+1))
done

called with argument 3000000.

Perhaps remarkable is that the "system" part of the time output is
relatively high: real 1m40.895s user 1m26.253s sys 0m14.641s is the
result on the xeon dual core machine.

Heiko

-- 

Dr. Heiko Schulz
Fachbereich Mathematik
Systemadministration
Pfaffenwaldring 57
Raum 8.313
Universität Stuttgart

Tel.   : (0711) 685 65344
Fax    : (0711) 685 65348
E-Mail : schulz@mathematik.uni-stuttgart.de