Verification failure in SPECJVM2008.scimark.fft.small on Windows/32bit

[Tom Rodriguez]

I haven't seen this before, though I pretty much never benchmark on  
windows.  Is the use of -XX:+CITime required? have you tried debug  
builds?  Does it reproduce with -XX:UseSSE=0?  It might be interesting  
to run with -XX:+CheckJNICalls which will verify the various fp  
control words have the right value.  I'll see if I can reproduce it  
here.

tom

On Oct 29, 2008, at 11:55 AM, Volker Simonis wrote:

> Hi,
>
> we have problems with SPECJVM2008 on Windows/x86 machines with at
> least 4 cores and at least 4 benchmark threads. The benchmark
> reproducible fails in the result verification of the sub-benchmark
> scimark.fft.small (however in random places).
>
> We could reproduce the problem with JDK 6u7 and 6u10 as well as with
> the latest JDK 7b38 however only for the 32-bit Windows versions.
>
> Because the problem occurs with both, C1 and C2 and because the
> problem isn't reproducible neither with  -Xint, nor with the 64-bit
> Windows or the Linux JDK, we think that this may be a problem in the
> HotSpot runtime (perhaps a timing/concurrency problem with the
> handling of 64-bit doubles in a 32-bit JDK on multi core machines?),
> but this is only a wild guess.
>
> We also observed that all the files (JDK, test classes and result
> files) had to be on the local host in order to reproduce the problem
> and we had the impression that the benchmark fails more quickly on
> Intel XEON, compared to AMD Opteron (we tested on the following
> hardware: Intel (2x XEON (with HT), 3.4GHz, 8GB, MS Win Server 2003
> Enterprise x64, SP1) and AMD (4x Opteron 270, 2.0GHz, 9GB, MS Win
> Server 2003 Enterprise x64, SP1)).
>
> Has anybody else already observed this problem? Is this perhaps an
> issue of SPECJVM2008.scimark.fft.small?
>
> Any comments would be highly appreciated!
>
> Regards,
> Volker
>
> PS: JVM2008 is available from http://www.spec.org/download.html
>
> PPS: here's the command line we used for the tests: java -server
> -XX:+CITime -Djava.io.tmpdir=tmp -jar SPECjvm2008.jar -ikv -wt 30 -it
> 60 -bt 4 --base scimark.fft.small scimark.fft.small scimark.fft.small
> scimark.fft.small scimark.fft.small scimark.fft.small
> scimark.fft.small scimark.fft.small scimark.fft.small
> scimark.fft.small scimark.fft.small scimark.fft.small
> scimark.fft.small scimark.fft.small scimark.fft.small
> scimark.fft.small scimark.fft.small scimark.fft.small
> scimark.fft.small scimark.fft.small