topic Re: OpenMP with libs:static cause memory leak in Intel® Fortran Compiler

OpenMP with libs:static cause memory leak

EruditePig — Thu, 24 Jun 2021 03:58:05 GMT

Here is the code:

program main implicit none integer :: i type Element real(8),allocatable :: eForce(:) end type Element type (Element),allocatable :: elems(:) allocate(elems(100)) !$omp parallel do private (i) schedule (guided) do i=1,100 allocate(elems(i)%eForce(1000000)) elems(i)%eForce=1. end do !$omp end parallel do write(*,*) "befor clean..." do while (.true.) write(*,fmt='(a,\)') "input 1 to continue：" read(*,*) i if(i.eq.1) exit end do deallocate(elems) write(*,*) "clean finished..." do while (.true.) write(*,fmt='(a,\)') "input 1 to continue：" read(*,*) i if(i.eq.1) exit end do end program main

If I choose "Debug Multithreaded (/libs:static /threads /dbglibs)" in project property, after clean the allocated memory, the memory usage is still near 1GB

However, If I choose "Debug Multithread DLL (/libs:dll /threads /dbglibs)", deallocate will perform right.

I notice that IVF stop support for static link of OpenMP (https://community.intel.com/t5/Intel-Fortran-Compiler/Intel-Fortran-Static-Library-with-OpenMP-enabled/td-p/1014804)

According to the thread, Am i wrong to choose the libs:static option?

The Intel Fortran version I used is 19.1.0.166

Re: OpenMP with libs:static cause memory leak

Steve_Lionel — Thu, 24 Jun 2021 14:40:02 GMT

/libs:static doesn't affect the OpenMP library, which is DLL-only. Have you tried a more recent compiler and runtime library?

Re: OpenMP with libs:static cause memory leak

EruditePig — Fri, 25 Jun 2021 00:27:01 GMT

the attachment is the solution, The Intel Fortran version I used is 19.1.0.166 , the VisualStudio version is 16.9.0
Both are recent updated software

Re: OpenMP with libs:static cause memory leak

Steve_Lionel — Fri, 25 Jun 2021 14:24:04 GMT

I can reproduce the difference using the 2021.0.2 compiler and libraries. What causes it, I don't know., but I do know that there can sometimes be issues mixing DLL and static linked code. If you have paid support I suggest you report this through the Intel Online Service Center. But the most pragmatic approach would be to use DLL linking, which is the default.

Re: OpenMP with libs:static cause memory leak

JohnNichols — Fri, 25 Jun 2021 14:58:54 GMT

Why is the default dll, it makes a lot more sense to bind in the lib.

Re: OpenMP with libs:static cause memory leak

Steve_Lionel — Fri, 25 Jun 2021 16:23:01 GMT

Linking to DLL libraries saves space, reduces memory load, and allows for DLLs to be updated without requiring a relink. Microsoft changed its defaults many years back to default to DLL linking. In the case of OpenMP, I recall a claim that there were run-time issues caused by use of a static library for OpenMP. I don't recall the details, and note that a static OMP library is still provided on Linux, but that is a different environment.

Re: OpenMP with libs:static cause memory leak

JohnNichols — Fri, 25 Jun 2021 16:48:45 GMT

but in the days of Microsoft Fortran you created a single file that sat on a floppy and just ran, now it is a convoluted set of dlls. Bring back MS Fortran V 3.03 and twin floppy drives, the modern youth are spoiled.