The purpose of this exercise is to compare different memory allocation strategies within a loop and to understand the performance impact of using or not using a memory pool. The following timed functions are called at the end of the source file by the main() function:
- The function
noRecurringAlloc()allocates memory outside loop only once - The function
recurringAllocNoMemPools()allocates memory within a loop recurringly - The function
recurringAllocMemPool()obtains memory from a pool within a loop recurringly
The task is to fill the missing function calls in the code indicated by lines beginning with #error, and followed by a descriptive instruction.
IMPORTANT NOTE! Unfortunately, the support for memory pools was only recently added to HIP (version 5.2.0), but the available HIP version at Puhti is only 5.1.0. Therefore, please replace the following HIP terms by the CUDA equivalents to make the application compile (in the future, the corresponding HIP commands should be available for use):
hipMallocAsync->cudaMallocAsynchipFreeAsync->cudaFreeAsync
Umpire is available at https://github.com/LLNL/Umpire/. Install Umpire with
git clone --recursive https://github.com/LLNL/Umpire.git
cd Umpire && mkdir build && cd build
cmake ../ -DUMPIRE_ENABLE_C=On -DENABLE_CUDA=On -DCMAKE_INSTALL_PREFIX=/path
make
make install
Compile the exercise with
hipcc --gpu-architecture=sm_70 -DHAVE_UMPIRE=1 mempools.cpp -I/path/umpire/include/ -L/path/umpire/lib/ -lcamp -lumpire