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.
- Configure the toolchain to use in the
Makefile:
TAG = GFORTRAN # Supported GFORTRAN, IFORT
- Review the flags for toolchain in the corresponding included file, e.g.
include_GFORTRAN.mk. OpenMP is disabled per default, you can enable it by uncommenting the OpenMP flag:
OPENMP = -fopenmp
- 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.
- Clean up with:
make clean
to clean intermediate build results.
make distclean
to clean intermediate build results and binary.
- (Optional) Generate assembler:
make asm
The assembler files will also be located in the <TOOLCHAIN> directory.
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-GFORTRAN
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 140210970978048 -> core 1 - OK
threadid 140210962585344 -> core 2 - OK
threadid 140210954192640 -> core 3 - OK
----------------------------------------------
Number of Threads = 4
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Function Rate (MB/s) Avg time Min time Max time
Init: 15068.23 0.0123 0.0106 0.0112
Sum: 21384.63 0.0088 0.0075 0.0082
Copy: 18854.08 0.0190 0.0170 0.0174
Update: 28157.37 0.0129 0.0114 0.0114
Triad: 19215.55 0.0281 0.0250 0.0263
Daxpy: 26606.76 0.0203 0.0180 0.0182
STriad: 21279.46 0.0339 0.0301 0.0309
SDaxpy: 26629.39 0.0271 0.0240 0.0240
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