Inconsistent results on bluegene

[Yu-Heng Tseng]

Hi Ross

I am testing it on NCAR's BG/L. These questions are really beyond my 
understanding. Sidd at NCAR should be able to answer your questions. 
Thanks!

Yuheng
---------------------------------------------------
Yu-Heng Tseng

Computational Research Division
Lawrence Berkeley National Laboratory
One Cyclotron Rd, MS: 50F-1650
Berkeley, CA94720
YHTseng at lbl.gov
510.495.2904

----- Original Message -----
From: Rob Ross <rross at mcs.anl.gov>
Date: Thursday, April 13, 2006 6:23 am
Subject: Re: Inconsistent results on bluegene

> Hi,
> 
> I see. Can you tell us what BG/L you are running on, what file 
> system it 
> has, and how it is mounted to the I/O nodes?
> 
> If not, can you CC someone that would know?
> 
> This could be an NFS thing.
> 
> Thanks,
> 
> Rob
> 
> Yu-Heng Tseng wrote:
> > Hi,
> > 
> > Here is the description of the problem.
> > In the test directory under test/fandc/
> > there is a Fortran test file called "pnf_test.F"
> > This file generates an array has size 256x256x256 and output it 
> to a 
> > pnf_test.nc file and read it back.
> > 
> > In other machines or using gcc to compile the library, it 
> compares the 
> > original array with the readin new array. The output have
> > diff, delmax, delmin
> > 
> > They should be all zero which represents the difference between 
> the 
> > new array and old array. Unfortunitely, I got some non-zero 
> values 
> > when I use 2, 8, 16 processors which means the new readin array 
> and 
> > original array are not identical.
> > The only correct result is using 1 processor. The new readin 
> array is 
> > identical to the old array.
> > 
> > I am not sure if there is anything wrong on the compiler or any 
> > problem. It looks fine when I use gcc to compile. Thank you so 
> much 
> > for your help!
> > 
> > Yu-heng
> > ---------------------------------------------------
> > Yu-Heng Tseng
> > 
> > Computational Research Division
> > Lawrence Berkeley National Laboratory
> > One Cyclotron Rd, MS: 50F-1650
> > Berkeley, CA94720
> > YHTseng at lbl.gov
> > 510.495.2904
> > 
> > ----- Original Message -----
> > From: Rob Ross <rross at mcs.anl.gov>
> > Date: Wednesday, April 12, 2006 7:28 pm
> > Subject: Re: Inconsistent results on bluegene
> > 
> >> Hi,
> >>
> >> Can you describe how the results are inconsistent?
> >>
> >> Thanks,
> >>
> >> Rob
> >>
> >> Yu-Heng Tseng wrote:
> >>> Hi,
> >>>
> >>> I am doing a testing on bluegene using. Surprisely, the 
> results 
> >> are not 
> >>> consistent when I use
> >>> multiple processors. There is no error when I compile and 
> >> install the 
> >>> library  I believe.
> >>> I use the test case from /fandc/pnf_test.F
> >>>
> >>> The compiler I am using is "blrts_xlc" I am not sure what 
> cause 
> >> the 
> >>> problem.
> >>> But when I use gcc to compile it. The results are consistent 
> for 
> >>> multiple processors.
> >>> Please give me some advices! Thanks!
> >>>
> >>> Yu-heng
> >>>
> > 
> 
>