I found out who the culprit is. It's the platform. The following patch disables the broken sendfile() implementation on s390-ibm-linux-gnu (see attachment).
After that patch, httpd-2.0 works both threaded and preforked. Thanks, Martin -- <[EMAIL PROTECTED]> | Fujitsu Siemens Fon: +49-89-636-46021, FAX: +49-89-636-41143 | 81730 Munich, Germany
Index: srclib/apr/configure.in =================================================================== RCS file: /home/cvs/apache/apr/configure.in,v retrieving revision 1.231 diff -u -r1.231 configure.in --- srclib/apr/configure.in 2001/02/20 03:03:34 1.231 +++ srclib/apr/configure.in 2001/02/21 13:56:52 @@ -648,6 +648,9 @@ *alpha*-dec-osf* ) sendfile="0" ;; + s390-*-linux-gnu) + sendfile="0" + ;; esac if test "$orig_sendfile" != "$sendfile"; then echo "sendfile support disabled to avoid system problem"