topic memory leaks using "heap_arrays" in Intel® Fortran Compiler

memory leaks using "heap_arrays"

dlemmon1 — Wed, 12 Dec 2007 21:05:21 GMT

The new "heap_arrays" option is great. But I'm noticing some occasional memory leaks which are quite serious. For instance, within a "where" block the program's memory usage suddenly begins to spike until it hits 4GB. The same thing happens while passing an array subset (using an array of indices) to a subroutine. These problems only occur when I build using the "heap_arrays" option.

My application is a DLL being called by a larger program (SAS). Unfortunately I haven't been able to reproduce the problems with example code, even when I'm calling the exact subroutine where the trouble occurs. Not sure why -- maybe I need to put my test case inside a DLL (need some time to do this...). Until I can do this, I'm not sure if I should go to the trouble of submitting a bug report. Anyway, I'm curious to see if anyone else has been seeing similar things with heap_arrays.

Re: memory leaks using "heap_arrays"

jimdempseyatthecove — Wed, 12 Dec 2007 21:29:41 GMT

If you are using the Page File information from Task Manager then the information you see is the amount of virtualmemory your program walked on. It is not the amount of memory for program + allocations.

Re: memory leaks using "heap_arrays"

dlemmon1 — Wed, 12 Dec 2007 22:18:28 GMT

Thanks for the help. I'll be more clear. I am looking at the column "Memory (Private Working Set)" for the host process (sas.exe) in Task Manager under "Processes". In the debugger it's simply performing a simple "where" block operation for a fairly large array, and the amount of memory starts rapidly increasing by hundreds of megabytes until it runs out of memory. So something strange is happening. Also, in the other scenario I mentioned, I'm passing array subsets to a function (using an indexing array), and each time I call the subroutine, the "Memory (Private Working Set)" for sas.exe increases by several megabytes, but it is not freed up after the function exits. I've tried to reproduce this situation in a simple Fortran program but it doesn't happen...

Re: memory leaks using "heap_arrays"

Steven_L_Intel1 — Wed, 12 Dec 2007 22:33:33 GMT

You will not see the working set go down when memory is freed. That memory is still in your address space in a pool belonging to the memory allocator.