[Nek5000-users] problem with running nek5000 on supercomputers

[nek5000-users at lists.mcs.anl.gov]

Thank you Dr. Fischer, I think it became so clear, maybe the problem for me
happened since I first ran nek with 32 processors and then I went to run it
on 1024! Which I found it little bit problematic on couple of cases that I
have tested!

Thank you,
Ami

On Tue, Nov 11, 2014 at 8:25 AM, <nek5000-users at lists.mcs.anl.gov> wrote:

>
>  Hi Ami,
>
>  Great to hear the problem is fixed!
>
>  In principle, it should suffice to simply
>
>  makenek blah
>
>  after editing the SIZE file, since make is smart enough to know that
> you've touched SIZE.
>
>  Normally I don't recompile when changing processor count (unless it's by
> a huge factor).
>
>  So, suppose my job has 4000 elements and I'm running on anywhere from 16
> to 2048
> processors.  It's sufficient to set lelt=(4000/16) and lp=2048.  Then you
> can run on that
> range P=16 to 2048 without recompile.
>
>  Paul
>
>
> ------------------------------
> *From:* nek5000-users-bounces at lists.mcs.anl.gov [
> nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
> nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
> *Sent:* Tuesday, November 11, 2014 3:23 AM
> *To:* nek5000-users at lists.mcs.anl.gov
> *Subject:* Re: [Nek5000-users] problem with running nek5000 on
> supercomputers
>
>   It seems that for each time I had to clean compiled files before
> changing the processor count and run it again! It works now!
>
>  Thanks,
> Ami
>
> On Mon, Nov 10, 2014 at 4:29 PM, Amirreza Hashemi <
> amirezahashemi at gmail.com> wrote:
>
>>   Dr. Fishcer,
>>
>>  Thanks for your answer, for sure, I change the lelt and lelg and keep
>> them as lowest even number that I can pick when I increase the number of
>> CPUs. I picked also lp=32768, but I still get this "allocation failed"
>> error. Is there any thing else that effect on the allocation which I have
>> to change it?!
>>
>>  Thanks,
>>  Ami
>>
>>  On Mon, Nov 10, 2014 at 8:55 AM, <nek5000-users at lists.mcs.anl.gov>
>> wrote:
>>
>>>
>>>  Hi Ami,
>>>
>>>  When you increase the processor count, you can recompile with a
>>> smaller lelt.
>>>
>>>  Suppose you have lelt=1000 and you go from P=64 to P=128.  Then set
>>> lelt=500 and
>>> recompile.
>>>
>>>  Make certain lelg >= 500*P and lp >= 128.
>>>
>>>  I would suggest lelg="big enough" (and an even number) and lp=32768.
>>>
>>>  Paul
>>>
>>>  ------------------------------
>>> *From:* nek5000-users-bounces at lists.mcs.anl.gov [
>>> nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
>>> nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
>>> *Sent:* Monday, November 10, 2014 5:05 AM
>>> *To:* nek5000-users at lists.mcs.anl.gov
>>> *Subject:* [Nek5000-users] problem with running nek5000 on
>>> supercomputers
>>>
>>>     Hi Neks,
>>>
>>>  I am trying to run my simulation with nek5000 on supercomputers, the
>>> size of the problem is something like:
>>>
>>>  text	   data	    bss	    dec	    hex	filename
>>> 2233955	 187412	2554984280	2557405647	986ee9cf	nek5000
>>>
>>>  I don't have any problem when I use 32~64 CPUs to run parallel on
>>> supercomputers, but once I go for more than 64 CPUs, I always get
>>> "allocation failed" error. I have tried to run on different supercomputer
>>> like as Gordon SDSC, OSC, TACC, but I got the same type of error each time.
>>> I have checked the active memories, it seems for each of them memories have
>>> large unused portion. Does any one have any idea why when I increase the
>>> number of CPUs I get this allocation error?!
>>>
>>>  Thank you,
>>> Ami
>>>
>>>  _______________________________________________
>>> Nek5000-users mailing list
>>> Nek5000-users at lists.mcs.anl.gov
>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>>
>>>
>>
>
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