Petsc Error

[Berend van Wachem]

Hi,

I am using 32 bit linux (slackware) on a 64 bit opteron. Would using a 
64 bit linux distro help?

Berend.


Barry Smith wrote:
>   Pressure your vendors, be they IBM or Redhat, to provide a 2007 OS instead
> of a 2001 OS :-(.
> 
>    Barry
> 
> 
> On Tue, 9 Oct 2007, Berend van Wachem wrote:
> 
>> Hi Barry,
>>
>> Yes, your hint seems correct; a single process can "only" allocate 3 gigabytes
>> of memory, even if there is more physical memory present.
>>
>> Is the only work around to run parallel?
>>
>> Thanks,
>> Berend.
>>
>>
>> Barry Smith wrote:
>>>   On most OS's just because you have greater than a certain amount of
>>> physical memory does not mean that a SINGLE process can utilize it.
>>> For example, many times a single process is limited to 2, 3 or 4 gigabytes.
>>> This is EVEN with 64 bit pointers (and certainly with 32 bit).
>>>
>>>    Barry
>>>
>>> Run a simple C program that mallocs a chunk of memory. How much you you
>>> malloc?
>>>
>>> On Tue, 9 Oct 2007, Berend van Wachem wrote:
>>>
>>>> Hi,
>>>>
>>>> I ran the same command again, running top, and got the result
>>>>
>>>> Mem:   6220940k total,  5879056k used,   341884k free,   143992k buffers
>>>> Swap:  1951888k total,     2584k used,  1949304k free,  2363516k cached
>>>>
>>>>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>>>> 19117 berend    25   0 3037m 2.5g 3508 R  100 41.4   0:44.96 MultiFlow
>>>>
>>>>
>>>>
>>>> just before it crashed. I have a 2 processor machine with total 6 GB of
>>>> memory
>>>> (2 times 3 gb?), so I don't think it should be out of memory. How can I
>>>> verify
>>>> this for sure?
>>>>
>>>> Thanks,
>>>>
>>>> Berend.
>>>>
>>>>
>>>>
>>>> Matthew Knepley wrote:
>>>>> On 10/9/07, Berend van Wachem <berend at chalmers.se> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On the command
>>>>>>
>>>>>>   ierr = DACreateLocalVector(da,g); CHKERRQ(ierr);
>>>>>>
>>>>>> I get the error
>>>>>>
>>>>>>
>>>>>> [0]PETSC ERROR: PetscMallocAlign() line 61 in src/sys/memory/mal.c
>>>>>> Memory requested 6050600
>>>>>> [0]PETSC ERROR: PETSC: Attaching gdb to Debug/MultiFlow of pid 19087
>>>>>> on
>>>>>> display :0.0 on machine tfdpc102
>>>>>>
>>>>>>
>>>>>> What does it mean exactly? Out of memory?
>>>>> Yes. This is strange. The line above these two should read "Out of
>>>>> memory".
>>>>>
>>>>>   Matt
>>>>>
>>>>>> Thanks,
>>>>>> Berend.
>>>>>>
>>>>>>
>>
>