Re: Windows array allocation problem



On Sep 30, 6:03 am, Roy Lewallen <w...@xxxxxxxxx> wrote:

The test shows that even for the simplest
program, the Intel compiler doesn't allow allocating as much of the
application virtual memory as the Compaq compiler does, at least not to
one large array.

That is an odd result as it's actually the runtime library that does
the allocation and the operating system that determines whether or not
allocation will succeed. The Intel runtime library, at least that
part of it, is essentially the same as the Compaq library. I would
guess that there is some other factor involved.

In version 10 of Intel Visual Fortran there is a sample program
Win32\ProcessStatus that displays virtual memory availability for each
process on the system. This does not mean that you can always
allocate that much memory.

Steve

.



Relevant Pages

  • Re: Windows array allocation problem
    ... I've just written a program which does nothing except call GlobalMemoryStatus to get the available virtual memory, then allocates an array to that size and in decreasing steps until STAT returns zero. ... The maximum allocation is consistently 146 MB less than the reported available virtual memory. ... So the phenomenon isn't due only to how Windows handles virtual memory but how the compiler handles it. ... The test shows that even for the simplest program, the Intel compiler doesn't allow allocating as much of the application virtual memory as the Compaq compiler does, at least not to one large array. ...
    (comp.lang.fortran)
  • Re: Windows array allocation problem
    ... application virtual memory as the Compaq compiler does, ... the allocation and the operating system that determines whether or not ... It shows that the remaining virtual memory is apparently usable, it just can't all be allocated to the first array. ...
    (comp.lang.fortran)
  • Re: Windows array allocation problem
    ... If the required size exceeds the possible size, the program has internal virtual memory management to solve the problem in pieces, storing intermediate pieces on the disk. ... much is available for an actual allocation. ... since the array dimension and the determination of whether to use the virtual memory manager are presently being determined by the calling program and passed in. ...
    (comp.lang.fortran)
  • Re: GC performance - GC fragility
    ... Though the GC heap will look like one before compaction. ... allocation sizes to different "heap blocks", but it can't be IMHO generally be prevented. ... If you only have macro-fragmentation in the virtual memory space, you can operate with limited fragmentation-induced waste in the allocated memory space. ... that's because the concurrent GC can be gotten into a cycle of never ending GC compaction if your allocation rate exceeds or equals the compaction rate, a condition easy to reach when part of your allocated pool is swapped out. ...
    (borland.public.delphi.non-technical)
  • Re: array allocation in a subroutine
    ... >> Are you using Intel Fortran 8.0? ... assume an allocation status of "not currently allocated" on entry to the ... The Intel compiler gets this half-right, ... Since I have the free, unsupported version of the compiler, I'm ...
    (comp.lang.fortran)