Petsc Error

[Barry Smith]

  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.
> > > > > 
> > > > > 
> > > > 
> > > 
> > 
> 
>