Date: Wed, 12 Aug 1998 14:13:12 +0200 (CEST) From: Remy NONNENMACHER <remy@synx.com> To: patton@sysnet.net Cc: freebsd-smp@FreeBSD.ORG Subject: Re: hanging second processor Message-ID: <199808121213.NAA01791@bsd.synx.com> In-Reply-To: <l03110719b1f55f1e7876@[192.168.1.10]>
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On 10 Aug, Matthew Patton wrote:
> I'm running -current as of 2 days ago. The box is a Dual PPRO 240 (180's
> overclocked). I don't know where to lay the blame on this one yet but here
> goes.
>
> There is no user load but I'm running Distributed.net's rc5des crackers on
> the machine. It may take 5 minutes or 3 days but I eventually "loose" the
> second CPU. The rc5des process that was apparently running on it hangs, and
> I can't kill it no matter what I do. A shutdown (clean) and a hardware
> reset is needed to unwedge the processor. The main processor runs just
> peachy 100% of the time.
>
> Is the problem buggy rc5des code? Or some sort of race condition or bug in
> the FreeBSD scheduler? Apparently the program doesn't fork or thread itself
> to take advantage of 2 processors otherwise I would have specified
> numcpu=2. If I run 1 instance, it gives me 690kkeys/sec (the expected rate
> for a single processor). If I run 2 instances I get 690kkyes/sec/processor
> which leads me to believe each CPU is getting an instance. Anyone have an
> idea as to the problem? Are there some SMP aware programs that I can run
> for days that will hammer the CPU's?
>
I think that :
main() {int i; while (1) i++;}
will be just sufficient to lock your processor ;). (just start two of
them).
rc5des is a well known processor burner (just like a windows machine
!!). Unix way of life keep processors cool (due to idle time) so you
can overclock quiet safely. As soon as you try to fry eggs with your
processors (running an endless, processor consuming, program), an
overclocked processor may goes to high in temp. to properly function.
I think that your second processor have a smaller temp operational
limit than your first one !!
For myself, i stopped helping rc5des on critical machines for
temperature problems.
RN.
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