Inconsistent results on bluegene

[Rob Ross]

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
>>>
>