FreeBSD 5.3-RELEASE + JDK1.4 native in a Jail -> hangs 99% cpu on kserel

[Joris Verschoor]

Hello,

I've installed a 5.3-RELEASE box. I haven't changed anything from the 
default kernel.
The box is a single cpu P4 with HT disabled.
I've set some sysctl vars:
security.jail.sysvipc_allowed: 1 (for pg in a jail)



There are 2 jails on my box:
1) Java 1.4.2 native port + resin3
2) PostgreSQL-7(.4)

PostgreSQL runs fine (I think)

I've installed a webapp on resin3 using the pg jdbc drivers. Everything 
runs fine and dandy, but after a while, I suddenly get two things:

******** 1 ********
And exception while opening a connection to pg.

Caused by: org.postgresql.util.PSQLException:
An I/O error occured while reading from backend
Exception: java.net.SocketException: Resource temporarily unavailable
Stack Trace:

java.net.SocketException: Resource temporarily unavailable
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.read(SocketInputStream.java:129)
        at java.io.BufferedInputStream.fill(BufferedInputStream.java:183)
... etc

******** 2 ********
the java process runs on 98% in the kserel state.
When it's in this state it won't serve any requests.
It is killable (killall -9 java and the perl wrapper).

I'm still not sure if nr 2 happens because of nr 1.


I haven't tried green threads yet.


Is this a known problem, and if so, what can I do to resolve it?

What does problem 1 mean?
Is this a problem caused by java(jailed) or pg(jailed)?
What is state is kserel?
Is there anything I can do to provide more information, for example a 
dump when it's stuck?


Thanks