[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Petsc Error

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@xxxxxxxxxxx> 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.