[distcc] trouble utilizing server cpu

[Marcin S]

Hello,
Im having trouble getting distcc to user full power of distcc server host.

Here are my configs

 cat /etc/distcc/hosts
192.168.1.20/20

running distccd with following command
/usr/bin/distccd --daemon --pid-file /var/run/distccd/distccd.pid -j
20 --port 3632 --log-level info --log-file /distcclog --allow
192.168.1.13 -N 0


make gets -j20.

here is example distccmon-text output

10106  Blocked                                                            [3]
 10078  Blocked                                                            [9]
 10110  Preprocess  x-php.c                                    192.168.1.20[0]
 10095  Preprocess  x-awk.c                                    192.168.1.20[1]
 10086  Preprocess  x-java.c                                   192.168.1.20[2]
 10087  Preprocess  x-csharp.c                                 192.168.1.20[3]
 10096  Preprocess  x-ycp.c                                    192.168.1.20[4]
 10099  Preprocess  x-tcl.c                                    192.168.1.20[6]
 10077  Preprocess  x-scheme.c                                 192.168.1.20[7]

 10078  Blocked                                                            [9]
 10110  Preprocess  x-php.c                                    192.168.1.20[0]
 10124  Preprocess  msgattrib.c                                192.168.1.20[1]
 10116  Preprocess  x-glade.c                                  192.168.1.20[2]
 10106  Preprocess  x-perl.c                                   192.168.1.20[3]
 10128  Preprocess  msgcat.c                                   192.168.1.20[4]
 10115  Preprocess  x-rst.c                                    192.168.1.20[5]
 10129  Preprocess  msgcomm.c                                  192.168.1.20[6]
 10130  Preprocess  msgconv.c                                  192.168.1.20[7]
 10077  Compile     x-scheme.c                                 192.168.1.20[7]


It's usualy Preprocess, very rarely Compile - altrought I didnt found
what "Preprocess" means...

So its sending some jobs to server, but cpu load at server is usualy
<10% and compiler process "cc1" spawns very rarely. Most "Compile"
jobs running on localhost.
Can someone help me to figure out whats going on?

Regards