Re: [Gems-users] Processor Lost

[Dan Gibson <degibson@xxxxxxxx>]

Good idea. This is a great option when a workload doesn't need the 
various goodies that run in multiuser mode.
Daniel Nussbaum - Sun Microsystems - Burlington United States wrote:
> Hi James.
>
> It might help to boot the (simulated) OS down to single-user mode, to
> reduce the range of possible background tasks that might interfere
> with your runs.
>
> To do this, type
>
>   shutdown -y -g0 -is
>
> at the shell prompt (running simics -fast, without ruby loaded), then
> wait for a fairly long time, then when it asks for the root password,
> hit ENTER.  At that point, (simulated) Solaris will booted in
> single-user mode.  Save the configuration, and run all of your tests
> starting from that point.
>
> You'll need to do this separately for 1-, 2-, 4-, etc. processor
> machines as needed.
>
> This is the environment from which we run all of our tests.
>
> dann
>
>   
> > Date: Thu, 03 May 2007 09:22:54 -0500
> > From: Kevin Moore <kmoore@xxxxxxxxxxx>
> >
> > James,
> >
> > 	Binding a thread to a processor does not mean that it will run
> > there continuously.  It just means that the thread will only run on
> > that processor.  If you've created a processor set (psrset), and
> > bound only the one thread to that set, no other user threads will
> > run in that set.  But, OS processes can and do sometimes run on
> > bound processors.  For whatever reason, Solaris likes to run mostly
> > on processor 0.  For that reason, what we typically do is to create
> > a processor set for each other processor (not p0) and bind our
> > threads to those sets.
> >
> > --Kevin
> >
> > James Wang wrote:
> >     
> > > Hi Dan:
> > >
> > >     Thank you very much for your prompt reply. But I don't really
> > >     understand what the nature of this situation is. Why would the
> > >     OS want to deschedule my benchmark? Also, I bound the thread
> > >     to the processor, should it just stay there and run? I did
> > >     this with a four processor simulated machine, why other
> > >     processors are not affected by this problem?
> > >
> > > Regards
> > > James
> > >
> > > ----- Original Message ----
> > > From: Dan Gibson <degibson@xxxxxxxx>
> > > To: Gems Users <gems-users@xxxxxxxxxxx>
> > > Sent: Friday, May 4, 2007 1:03:42 AM
> > > Subject: Re: [Gems-users] Processor Lost
> > >
> > > The OS could be descheduling your transactional benchmark, though
> > > I'm not sure why that might be happening. Try quiescing the system
> > > by killing background processes, and then pre-fetch any binaries
> > > or data you might be using in your benchmark by running it once to
> > > completion before loading Ruby (and hence, without
> > > synchronization). That should eliminate any I/O you might
> > > inadvertenly cause at runtime. It will also cause your benchmark
> > > to run with different system interactions, and will hopefully fix
> > > the Processor Lost/Processor Found problem.
> > >
> > > Regards,
> > > Dan
> > >
> > > James Wang wrote:
> > >
> > >       
> > > > Hi All:
> > > >
> > > >    I am running some transactional memory benchmark using a
> > > >    customized SMP cache coherent protocol. For some reason, p0
> > > >    will run code other than the transactional benchmark and the
> > > >    other processors finishes fine. I cannot really tell what p0
> > > >    is doing. I tried a few different random seed, the same
> > > >    situation happens every time.
> > > >
> > > >    Any idea?
> > > >
> > > >    Thanks for any reply in advance.
> > > >
> > > > Regards
> > > > James
> > > >
> > > >         
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