HeapBufMP_alloc: Ran out of memory blocks

Hi 

   I  using syslink ListMP to correspondence with DSP. 

  I do this:Arm Buffer(HeapBufMP_alloc)->DSP(process)->ARM free(HeapBufMP_free)

  But I got error yet:

<1>*** HeapBufMP_alloc: Ran out of memory blocks!
Error [0xfffffffd] at Line no: 1077 in file /work/mcsdk/mcsdk_1_01_00_02/syslink_2_21_01_05/packages/ti/syslink/utils/hlos/knl/Linux/../../../../../../ti/syslink/ipc/hlos/knl/HeapBufMP.c

What's wrong about it?  And what should I do to resolve it?

Thanks very much!