AW: AW: Need SMP access (FreeBSD port of SAPDB aka MaxDB (fwd))
eischen at vigrid.com
Thu Oct 2 11:41:27 PDT 2003
On Thu, 2 Oct 2003, Kai Mosebach wrote:
> > > Hi,
> > >
> > > We can do most of the single processor stuff on our own test
> > > but we do not know yet, how it behaves (or even if it behaves) on a
> > > using kse. The more important aspect to us though is, that some of
> > > threading specialists can take a look on some behaviours and
> > > misbehaviours, and mabe tell us whether its from the code, nor from
> > > kse implementation ;).
> > Well, just get it working under FreeBSD with native threading
> > (KSE) and modify the port to respect PTHREAD_LIBS instead of
> > linuxthreads. Others can help you test on SMP, but in theory
> > it should behave no differently than on UP. You can simulate
> > KSE/SMP on a UP system by setting the following sysctls:
> Native KSE threading is already done. Some problems occurred though,
> which yet seem to be scheduling problems in the threading (A complete
> database backup runs, but does not responds correctly, when finished.).
Can you tell me what you mean "does not responds correctly". Are
you forking and waiting for SIGCHLD or something?
> Question from a SAP Developer was, if there are there ways for
> "scheduling checks" in the lib ?
You can define DEBUG_THREAD_KERN (in libpthread/thread/thr_kern.c)
and DEBUG_SIGNAL (in libpthread/thread/thr_sig.c), but that will
give you a lot of output and may end up screwing other things
up. You can also send the process a SIGINFO and it will dump
the threads and their states to /tmp/pthread.dump.pid.n.
> > kern.threads.debug: 0 -> 1
> > kern.threads.virtual_cpu: 1 -> 2
> > Let us know if you have any problems.
> I will try that ...
Make sure your libpthread is up to date. There have been a few
fixes in the last few weeks.
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