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