Merge branch 'master' of github.com:RRZE-HPC/TheBandwidthBenchmark

README.md

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+# 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 `<TOOLCHAIN>` 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 `<TOOLCHAIN>` directory.
+
+## Usage
+
+To run the benchmark call:
+```
+./bwBench-<TOOLCHAIN>
+```
+
+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
+```