update README and doc
[LbmBenchmarkKernelsPublic.git] / doc / main.rst
index 528b339be1c37a3bd522bba6256905b16d916428..0eaa5ede892a7ace3ef476479acc3dfbe58ebe3b 100644 (file)
@@ -35,12 +35,26 @@ LBM Benchmark Kernels Documentation
 .. sectnum::
 .. contents::
 
+Introduction
+============
+
+The lattice Boltzmann (LBM) benchmark kernels are a collection of LBM kernel
+implementations.
+
+**AS SUCH THE LBM BENCHMARK KERNELS ARE NO FULLY EQUIPPED CFD SOLVER AND SOLELY
+SERVES THE PURPOSE OF STUDYING POSSIBLE PERFORMANCE OPTIMIZATIONS AND/OR
+EXPERIMENTS.**
+
+Currently all kernels utilize a D3Q19 discretization and the
+two-relaxation-time (TRT) collision operator [ginzburg-2008]_.
+All operations are carried out in double precision arithmetic.
+
 Compilation
 ===========
 
 The benchmark framework currently supports only Linux systems and the GCC and 
 Intel compilers. Every other configuration probably requires adjustment inside
-the code and the makefiles. Further some code might be platform or at least
+the code and the makefiles. Furthermore some code might be platform or at least
 POSIX specific.
 
 The benchmark can be build via ``make`` from the ``src`` subdirectory. This will
@@ -49,6 +63,11 @@ generate one binary which hosts all implemented benchmark kernels.
 Binaries are located under the ``bin`` subdirectory and will have different names
 depending on compiler and build configuration.
 
+Compilation can target debug or release builds. Combined with both build types
+verification can be enabled, which increases the runtime and hence is not
+suited for benchmarking.
+
+
 Debug and Verification
 ----------------------
 
@@ -69,6 +88,16 @@ Specifying ``BENCHMARK=off`` turns on verification
 Please note that the generated binary will therefore
 exhibit a poor performance.
 
+
+Release and Verification
+------------------------
+
+Verification with the debug builds can be extremely slow. Hence verification
+capabilities can be build with release builds: ::
+
+  make BENCHMARK=off 
+
+
 Benchmarking
 ------------
 
@@ -77,16 +106,11 @@ To generate a binary for benchmarking run make with ::
   make 
 
 As default ``BENCHMARK=on`` and ``BUILD=release`` is set, where
-BUILD=release turns optimizations on and ``BENCHMARK=on`` disables
+``BUILD=release`` turns optimizations on and ``BENCHMARK=on`` disables
 verfification, statistics, and VTK output.
 
-Release and Verification
-------------------------
-
-Verification with the debug builds can be extremely slow. Hence verification
-capabilities can be build with release builds: ::
-
-  make BENCHMARK=off 
+See Options Summary below for further description of options which can be
+applied, e.g. TARCH as well as the Benchmarking section.
 
 Compilers
 ---------
@@ -116,15 +140,15 @@ all object and dependency files are deleted.
 Options Summary
 ---------------
 
-Options that can be specified when building the framework with make:
+Options that can be specified when building the suite with make:
 
 ============= ======================= ============ ==========================================================
 name          values                  default      description
-------------- ----------------------- ------------ ----------------------------------------------------------
+============= ======================= ============ ==========================================================
 BENCHMARK     on, off                 on           If enabled, disables VERIFICATION, STATISTICS, VTK_OUTPUT. If disabled enables the three former options.
-BUILD         debug, release          release      No optimization, debug symbols, DEBUG defined.
+BUILD         debug, release          release      debug: no optimization, debug symbols, DEBUG defined. release: optimizations enabled.
 CONFIG        linux-gcc, linux-intel  linux-intel  Select GCC or Intel compiler. 
-ISA           avx, sse                avx          Determines which ISA extension is used for macro definitions. This is *not* the architecture the compiler generates code for.
+ISA           avx, sse                avx          Determines which ISA extension is used for macro definitions of the intrinsics. This is *not* the architecture the compiler generates code for.
 OPENMP        on, off                 on           OpenMP, i.\,e.\. threading support.
 STATISTICS    on, off                 off          View statistics, like density etc, during simulation. 
 TARCH         --                      --           Via TARCH the architecture the compiler generates code for can be overridden. The value depends on the chosen compiler.
@@ -175,7 +199,7 @@ iterations, etc, which can afterward be override, e.g.: ::
 
   $ bin/lbmbenchk-linux-intel-release -verfiy -dims 32x32x32
 
-Kernel specific parameters can be opatained via selecting the specific kernel
+Kernel specific parameters can be obtained via selecting the specific kernel
 and passing ``-h`` as parameter: ::
 
   $ bin/lbmbenchk-linux-intel-release -kernel kernel-name -- -h
@@ -299,13 +323,51 @@ created make sure the binary was compiled with:
 - ``BUILD=release`` (default if not overriden) and 
 - the correct ISA for macros is used, selected via ``ISA`` and
 - use ``TARCH`` to specify the architecture the compiler generates code for.
+  
+Intel Compiler
+--------------
+
+For the Intel compiler one can specify depending on the target ISA extension:
+
+- AVX:          ``TARCH=-xAVX``
+- AVX2 and FMA: ``TARCH=-xCORE-AVX2,-fma``
+- AVX512:       ``TARCH=-xCORE-AVX512``
+- KNL:          ``TARCH=-xMIC-AVX512``
+
+Compiling for an architecture supporting AVX (Sandy Bridge, Ivy Bridge): ::
+
+  make ISA=avx TARCH=-xAVX
+
+
+Compiling for an architecture supporting AVX2 (Haswell, Broadwell): ::
+
+  make ISA=avx TARCH=-xCORE-AVX2,-fma
+
+WARNING: ISA is here still set to ``avx`` as currently we have the FMA intrinsics not
+implemented. This might change in the future.
+
+
+Compiling for an architecture supporting AVX-512 (Skylake): ::
+
+  make ISA=avx TARCH=-xCORE-AVX512
+
+WARNING: ISA is here still set to ``avx`` as currently we have no implementation for the
+AVX512 intrinsics. This might change in the future.
+
+
+Pinning
+-------
 
 During benchmarking pinning should be used via the ``-pin`` parameter. Running
-a benchmark with 10 threads an pin them to the first 10 cores works like ::
+a benchmark with 10 threads and pin them to the first 10 cores works like ::
 
   $ bin/lbmbenchk-linux-intel-release ... -t 10 -pin $(seq -s , 0 9)
 
-Things the binary does nor check or controll:
+
+General Remarks
+---------------
+
+Things the binary does nor check or control:
 
 - transparent huge pages: when allocating memory small 4 KiB pages might be
   replaced with larger ones. This is in general a good thing, but if this is
@@ -326,7 +388,7 @@ Things the binary does nor check or controll:
   used is already full memory might be allocated in a remote domain. Accesses
   to remote domains typically have a higher latency and lower bandwidth.
 
-- System load: interference with other application, espcially on desktop
+- System load: interference with other application, especially on desktop
   systems should be avoided.
 
 - Padding: For SoA based kernels the number of (fluid) nodes is automatically
@@ -378,14 +440,134 @@ like ``-pad 0+16`` would at a static padding of two nodes (one node = 8 b).
 Geometries
 ==========
 
-TODO: supported geometries: channel, pipe, blocks
-
-
-Results
-=======
-
-TODO
-
+TODO: supported geometries: channel, pipe, blocks, fluid
+
+
+Performance Results
+===================
+
+The sections lists performance values measured on several machines for
+different kernels and geometries.
+The **RFM** column denotes the expected performance as predicted by the
+Roofline performance model [williams-2008]_. 
+For performance prediction of each kernel a memory bandwidth benchmark is used
+which mimics the kernels memory access pattern and the kernel's loop balance
+(see [kernels]_ for details).
+
+Haswell, Intel Xeon E5-2695 v3
+------------------------------
+
+- Haswell architecture, AVX2, FMA
+- 14 cores, 2,3 GHz
+- 2 x 7 cores in cluster-on-die (CoD) mode enabled
+- SMT enabled
+
+memory bandwidth:
+
+- copy-19              47.3 GB/s
+- copy-19-nt-sl        47.1 GB/s
+- update-19            44.0 GB/s
+
+geometry dimensions:  500x100x100
+
+=========================    =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =====
+kernel                            pipe   blocks-2   blocks-4   blocks-6   blocks-8  blocks-10  blocks-15  blocks-16  blocks-20  blocks-25  blocks-32  RFM
+=========================    =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =====
+blk-push-aos                     58.82      49.85      57.34      59.90      61.37      62.17      65.30      64.00      67.54      64.46      69.69   104 
+blk-push-soa                     32.32      33.46      34.02      34.64      35.06      35.04      36.31      35.44      37.20      35.14      37.95   104
+blk-pull-aos                     56.97      51.41      56.09      57.92      59.98      59.83      63.37      61.55      65.50      63.11      67.02   104
+blk-pull-soa                     49.29      46.23      47.50      51.97      51.27      49.52      55.23      53.13      54.50      49.79      57.90   104
+aa-aos                           91.35      66.14      76.80      84.76      83.63      91.36      93.46      92.62      93.91      92.25      92.93   145
+aa-soa                           75.51      65.68      70.94      71.36      73.83      75.46      74.84      79.48      83.28      77.70      82.72   145
+aa-vec-soa                       93.85      83.44      91.58      93.96      94.35      96.62     101.76      96.72     106.37     102.60     110.28   145
+list-push-aos                    80.29      80.97      80.95      81.10      81.37      82.44      81.77      81.49      80.72      81.93      80.93   83
+list-push-soa                    47.52      42.65      45.28      46.64      43.46      40.59      44.94      46.55      41.53      45.98      44.86   83
+list-pull-aos                    85.30      82.97      86.43      83.42      86.33      83.70      86.43      83.77      83.10      85.89      84.44   83
+list-pull-soa                    62.12      63.61      63.28      61.32      66.72      62.65      64.82      60.49      58.01      64.46      62.52   83
+list-pull-split-nt-1s-soa       121.35     113.77     115.29     113.54     117.00     116.46     114.78     114.54     110.83     112.67     117.85   125
+list-pull-split-nt-2s-soa       118.09     110.48     112.55     113.18     113.44     111.85     109.27     114.41     110.28     111.78     113.74   125
+list-aa-aos                     121.28     118.63     119.00     118.50     121.99     119.11     118.83     121.47     121.62     126.18     120.12   129
+list-aa-soa                     126.34     116.90     129.45     127.12     129.41     121.42     126.19     126.76     126.70     124.40     125.22   129
+list-aa-ria-soa                 133.68     121.82     126.04     128.46     131.15     132.25     128.78     133.50     126.69     124.40     130.37   145
+list-aa-pv-soa                  146.22     124.39     130.73     136.29     137.61     131.21     138.65     138.78     127.02     132.40     138.37   145
+=========================    =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =====
+
+
+Broadwell, Intel Xeon E5-2630 v4
+--------------------------------
+
+- Broadwell architecture, AVX2, FMA
+- 10 cores, 2.2 GHz
+- SMT disabled
+
+memory bandwidth:
+
+- copy-19              48.0 GB/s
+- copy-nt-sl-19        48.2 GB/s
+- update-19            51.1 GB/s
+
+geometry dimensions:  500x100x100
+
+=========================   =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =======
+kernel                           pipe   blocks-2   blocks-4   blocks-6   blocks-8  blocks-10  blocks-15  blocks-16  blocks-20  blocks-25  blocks-32  RFM
+=========================   =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =======
+blk-push-aos                    55.75      47.62      54.57      57.10      58.49      59.00      61.72      60.56      64.05      61.10      66.03  105
+blk-push-soa                    30.06      31.09      32.13      32.54      32.74      32.72      33.81      33.19      34.90      33.21      35.75  105
+blk-pull-aos                    53.80      48.61      53.08      54.99      56.08      56.68      59.20      58.12      61.49      58.71      63.45  105
+blk-pull-soa                    46.96      46.61      48.84      49.70      50.33      50.46      52.36      51.39      54.20      51.61      55.71  105
+aa-aos                          91.40      66.99      78.47      83.38      86.62      88.62      92.98      91.54      97.08      94.93      98.90  168
+aa-soa                          83.01      69.96      75.85      77.72      79.01      79.29      82.38      80.11      85.70      83.91      87.69  168
+aa-vec-soa                     112.03      96.52     105.32     109.76     112.55     113.82     120.55     118.37     126.30     121.37     131.94  168
+list-push-aos                   75.13      74.18      75.20      75.42      75.24      75.99      75.80      75.80      75.54      76.22      76.21   97
+list-push-soa                   40.99      38.14      39.00      38.89      38.89      39.67      39.87      39.28      39.35      40.08      40.13   97
+list-pull-aos                   82.07      82.88      83.29      83.09      83.32      83.49      82.82      82.88      83.32      82.60      82.93   97
+list-pull-soa                   62.07      60.40      61.89      61.39      62.43      60.90      60.48      62.80      62.50      61.10      60.38   97
+list-pull-split-nt-1s-soa      125.81     120.60     121.96     122.34     122.86     123.53     123.64     123.67     125.94     124.09     123.69  128
+list-pull-split-nt-2s-soa      122.79     117.16     118.86     119.16     119.56     119.99     120.01     120.03     122.64     120.57     120.39  128
+list-aa-aos                    128.13     127.41     129.31     129.07     129.79     129.63     129.67     129.94     129.12     128.41     129.72  150
+list-aa-soa                    141.60     139.78     141.58     142.16     141.94     141.31     142.37     142.25     142.43     141.40     142.26  150
+list-aa-ria-soa                141.82     134.88     140.15     140.72     141.67     140.51     141.18     141.29     142.97     141.94     143.25  168
+list-aa-pv-soa                 164.79     140.95     159.24     161.78     162.40     163.04     164.69     164.38     165.11     165.75     166.09  168
+=========================   =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =======
+
+
+Skylake, Intel Xeon Gold 6148
+-----------------------------
+
+- Skylake architecture, AVX2, FMA, AVX512
+- 20 cores, 2.4 GHz
+- SMT enabled
+
+memory bandwidth:
+
+- copy-19                  89.7 GB/s
+- copy-19-nt-sl            92.4 GB/s
+- update-19                93.6 GB/s
+
+geometry dimensions:  500x100x100
+
+
+=========================    =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  ===
+kernel                            pipe   blocks-2   blocks-4   blocks-6   blocks-8  blocks-10  blocks-15  blocks-16  blocks-20  blocks-25  blocks-32  RFM
+=========================    =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  ===
+blk-push-aos                    113.01      93.99     108.98     114.65     117.87     119.47     124.95     122.46     129.29     123.87     133.01  197
+blk-push-soa                    100.21      98.87     103.63     105.56     107.02     107.27     111.61     109.83     116.16     110.51     110.29  197
+blk-pull-aos                    118.45     102.54     114.12     117.82     122.69     124.31     130.58     127.85     135.72     129.65     139.94  197
+blk-pull-soa                     82.60      83.36      87.13      88.39      88.84      88.96      92.48      90.93      95.79      91.92      98.64  197
+aa-aos                          171.32     125.43     147.73     157.70     163.35     167.25     175.39     174.20     182.54     173.67     187.76  308
+aa-soa                          180.85     152.39     165.84     152.59     171.90     175.76     184.94     182.34     189.43     180.30     193.54  308
+aa-vec-soa                      208.03     181.51     195.86     203.41     209.08     212.34     224.05     219.49     234.31     225.92     245.22  308
+list-push-aos                   158.81     164.67     162.93     163.05     165.22     164.31     164.66     160.78     164.07     165.19     164.06  177
+list-push-soa                   134.60     110.44     110.17     132.01     132.95     133.46     134.37     134.33     135.12     134.91     137.87  177
+list-pull-aos                   169.61     170.03     170.89     170.90     171.20     171.60     172.09     171.95     169.48     172.08     171.02  177
+list-pull-soa                   120.50     116.73     118.62     118.00     120.99     118.15     117.17     121.41     120.83     120.00     118.74  177
+list-pull-split-nt-1s-soa       225.59     224.18     225.10     226.34     226.01     230.37     227.50     228.42     227.39     231.65     227.35  246
+list-pull-split-nt-2s-soa       219.20     214.63     217.61     218.13     219.07     221.01     219.88     220.09     220.62     221.68     220.58  246
+list-aa-aos                     241.39     239.27     239.53     242.56     242.46     243.00     242.91     242.46     241.24     242.96     241.52  275
+list-aa-soa                     273.73     268.49     268.48     271.79     275.29     274.56     277.18     272.67     274.21     275.24     278.21  275
+list-aa-ria-soa                 288.42     261.89     273.26     284.84     283.88     288.29     290.72     289.81     293.36     290.75     292.93  308
+list-aa-pv-soa                  303.35     267.21     289.18     294.96     294.36     298.16     300.45     301.71     302.37     302.88     304.46  308
+=========================    =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  =========  ===
 
 Licence
 =======
@@ -401,6 +583,19 @@ This work was funded by BMBF, grant no. 01IH15003A (project SKAMPY).
 This work was funded by KONWHIR project OMI4PAPS.
 
 
+Bibliography
+============
+
+.. [ginzburg-2008]
+ I. Ginzburg, F. Verhaeghe, and D. d'Humières. 
+ Two-relaxation-time lattice Boltzmann scheme: About parametrization, velocity, pressure and mixed boundary conditions. 
+ Commun. Comput. Phys., 3(2):427-478, 2008.
+
+.. [williams-2008]
+ S. Williams, A. Waterman, and D. Patterson. 
+ Roofline: an insightful visual performance model for multicore architectures. 
+ Commun. ACM, 52(4):65-76, Apr 2009. doi:10.1145/1498765.1498785
+
 
 .. |datetime| date:: %Y-%m-%d %H:%M
 
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