topic this is how mkl memory in Intel® oneAPI Math Kernel Library

pardiso Memory leak?

Frank_W_1 — Tue, 14 May 2013 08:27:57 GMT

I feel very puzzled with the Win32 Pardiso version.

My integrated enviroment is Intel(R) Visual Fortran Compiler XE 12.1.7.371.

My matrix has 5 million non zeros ,and n =200,000 , real and symmetric indefinite

I first test the memory I could use(1022M could be used), then I call pardiso to do the 23 phase,then call pardiso to do the -1 phase;

then I test the memory I could use again,

I fould that only about 700 M Memory that could be used.

What should I do? Theoretically I could use 1022 M Memory again.

This doesnt happen under win64.

Hope for the reply.

Thanks.

I am not sure I understand

Gennady_F_Intel — Wed, 15 May 2013 05:43:46 GMT

I am not sure I understand your question: if you call pardiso with -1 phase, then you release all internal data structures and therefore the next time you need to make all steps ( symb. and numeric factorizations and forward / backward computation ) again. in the case if you will not call -1 phase, then you can reuse the factorizations.

Sorry, some details has been

Frank_W_1 — Wed, 15 May 2013 06:57:58 GMT

Sorry, some details has been expressed wrongly.
I haved called pardiso to do the 11,22,33 phase sequentially.
Then I need to do -1 phase to free the memorty that pardiso has allocated;
But when after I have done -1 phase,the memory space couldn't recover to
the original.
I guess some memory leak has happpened.

Sorry, some details has been

Frank_W_1 — Wed, 15 May 2013 06:58:01 GMT

this is how mkl memory

Gennady_F_Intel — Wed, 15 May 2013 17:05:48 GMT

this is how mkl memory manager works. Intel MKL has memory management software that controls memory buffers for the use by the library functions. New buffers that the library allocates when your application calls Intel MKL are not deallocated until the program ends. To get the amount of memory allocated by the memory management software, call the mkl_mem_stat() function. If your program needs to free memory, call mkl_free_buffers().

see more details into mkl's users Guide

Gennady，

Frank_W_1 — Wed, 29 May 2013 03:48:13 GMT

Gennady，

Thank you very much.

I have found the reason that the pointer pt(i) have been modified more than once.

The pointer pt(i) should be set to 0 always and must be used only at the beginning when one wants to call pardiso.

Except for the details of pointer pt(i) of mkl‘s users Guide, is there any other function of pt(i)?

Gennady Fedorov (Intel) wrote:

this is how mkl memory manager works. Intel MKL has memory management software that controls memory buffers for the use by the library functions. New buffers that the library allocates when your application calls Intel MKL are not deallocated until the program ends. To get the amount of memory allocated by the memory management software, call the mkl_mem_stat() function. If your program needs to free memory, call mkl_free_buffers().

see more details into mkl's users Guide

Hey Frank,

Dogan__Hakan — Thu, 30 May 2013 15:08:42 GMT

Hey Frank,

I have the same problem. How did you solve it at the end? Do you call the mkl_free_buffers() at end of the subroutine, i.e. after the -1 phase?

Or do you delete pt() somewhere in the subroutine?

Regards,

Hakan.

Hakan,

Frank_W_1 — Wed, 05 Jun 2013 07:10:15 GMT

Hakan,

The pointer pt(i) should be set to 0 always and must be used only once.

The mkl_free_buffers() has no effect at all. I think it has no relation with pardiso.

Frank