Re: NetBSD/java threading issues

[David Brownlee <abs%netbsd.org@localhost>]

On 11 December 2010 18:33, Francois Tigeot <ftigeot%wolfpond.org@localhost> 
wrote:
> On Thu, Dec 09, 2010 at 09:16:00PM +0100, Francois Tigeot wrote:
>> On Wed, Dec 08, 2010 at 07:29:58PM -0500, Martin S. Weber wrote:
>> > On Wed, Dec 08, 2010 at 08:25:22PM +0100, Francois Tigeot wrote:
>> > > (...)
>> > > some kaffe instances end up sitting in place and doing nothing. top and 
>> > > ps
>> > > show a running kaffe-bin process, using 0% cpu.
>> >
>> > Using scala (2.8.0) + lift (2.1) + jetty, you can achieve
>> > the same with ANY jre that runs on netbsd/i386
>>
>> It seems there were some similar issues in the past on FreeBSD. I have found
>> references to threading libraries and signal handling.
>
> This old mail is quite enlightening. It mentions a 'java compiler stuck in
> "pause" mode' :
> http://lists.freebsd.org/pipermail/freebsd-threads/2003-June/000713.html
>
> The FreeBSD guys changed their threading libraries during the years 2003-2004;
> they went from an userland-only implementation of the pthread api (libc_r)
> to two slightly different libraries using a M:N (libkse) or 1:1 (libthr)
> threading model and making use of kernel SMP features.
>
> The transition was quite painful, and java programs had exactly the same sort
> of issues we are now seeing on NetBSD.
>
> I just installed a NetBSD-4.01 system and had a go building wip/jdk15 on it:
> it ran without trouble for 45 minutes. There were no threads stuck, the
> bootstrap java compiler never failed.
>
> One of the big changes of NetBSD 5 was (surprise, surprise) a brand-new
> threading subsystem.
> So, I think there's something slightly borked with the new threading system.
> Unfortunately, I don't have enough system-level knowledge to find out more.

I don't have any thoughts on how to resolve this, but possibly a
couple of collecting more information:

Is your machine multiprocessor? If so could you try booting with only
one CPU enabled and see if the threading issues exhibit? Also,
possibly try running the netbsd-4 binary under netbsd-5 (probably with
'sysctl -w kern.no_sa_support=0' first).