diff --git a/README.md b/README.md new file mode 100644 index 0000000..2003abe --- /dev/null +++ b/README.md @@ -0,0 +1,93 @@ +# The Bandwidth Benchmark + +This is a collection of simple streaming kernels for teaching purposes. +It is heavily inspired by John McCalpin's https://www.cs.virginia.edu/stream/. + +It contains the following streaming kernels with corresponding data access pattern (Notation: S - store, L - load, WA - write allocate): + +* init (S1, WA): Initilize an array. Store only. +* sum (L1): Vector reduction. Load only. +* copy (L1, S1, WA): Classic memcopy. +* update (L1, S1): Update a vector. Also load + store but without write allocate. +* triad (L2, S1, WA): Stream triad - `a = b + b * scalar`. +* daxpy (L2, S1): Daxpy - `a = a + b * scalar`. +* striad (L3, S1, WA): Schoenauer triad - `a = b + c * d`. +* sdaxpy (L3, S1): Schoenauer triad without write allocate - `a = a + b * c`. + + +## Build + +1. Configure the toolchain to use in the `Makefile`: +``` +TAG = GCC # Supported GCC, CLANG, ICC +``` + +2. Review the flags for toolchain in the corresponding included file, e.g. `include_GCC.mk`. OpenMP is disabled per default, you can enable it by uncommenting the OpenMP flag: +``` +OPENMP = -fopenmp +``` + +3. Build with: +``` +make +``` + +You can build multiple toolchains in the same directory, but notice that the Makefile is only acting on the one currently set. +Intermediate build results are located in the `` directory. + +4. Clean up with: +``` +make clean +``` +to clean intermediate build results. + +``` +make distclean +``` +to clean intermediate build results and binary. + +5. (Optional) Generate assembler: +``` +make asm +``` +The assembler files will also be located in the `` directory. + +## Usage + +To run the benchmark call: +``` +./bwBench- +``` + +The benchmark will output the results similar to the stream benchmark. Results are validated. +For threaded execution it is recommended to control thread affinity. + +We recommend to use likwid-pin for benchmarking: +``` +likwid-pin -c 0-3 ./bwbench-GCC +``` + +Example output for threaded execution: +``` +------------------------------------------------------------- +[pthread wrapper] +[pthread wrapper] MAIN -> 0 +[pthread wrapper] PIN_MASK: 0->1 1->2 2->3 +[pthread wrapper] SKIP MASK: 0x0 + threadid 140271463495424 -> core 1 - OK + threadid 140271455102720 -> core 2 - OK + threadid 140271446710016 -> core 3 - OK +OpenMP enabled, running with 4 threads +------------------------------------------------------------- +Function Rate (MB/s) Avg time Min time Max time +Init: 14681.5000 0.0110 0.0109 0.0111 +Sum: 20634.9290 0.0079 0.0078 0.0082 +Copy: 18822.2827 0.0172 0.0170 0.0176 +Update: 28135.9717 0.0115 0.0114 0.0117 +Triad: 19263.0634 0.0253 0.0249 0.0268 +Daxpy: 26718.1377 0.0182 0.0180 0.0187 +STriad: 21229.4470 0.0305 0.0301 0.0313 +SDaxpy: 26714.3897 0.0243 0.0240 0.0253 +------------------------------------------------------------- +Solution Validates +```