MISC-TN-008: Running Debian Buster (armbian) on Mito8M

Info Box Applies to MITO 8M

This technical note was validated against specific versions of hardware and software. What is described here may not work with other versions.

History

Version	Date	Notes
1.0.0	January 2020	First public release

Introduction

Mito8M is the first DAVE Embedded Systems' product based on a core implementing the ARMv8-A architecture. Traditionally, ARM cores that are based on 32-bit ARMv7-A architecture exhibit a limited RAM bandwidth even if they are coupled with 64-bit witdh SDRAM banks. When dealing with computationally heavy tasks, this factor may turn out to be a severe bottleneck limiting the overall performance.

Beside an intrinsic increased computational power, ARMv8-A-based SoC's are expected to improve significantly RAM bandwidth as well. This technical note (TN for short) illustrates several benchmarking tests that were run on Mito8M SoM, which is built upon NXP i.MX8M Quad.

Testbed general configuration

This section illustrates the configuration settings common to all the tests performed.

SoC and SDRAM bank organization

		Mito8M
SoC	SoC	NXP i.MX8M Quad
	ARM frequency [MHz]	800
SDRAM	Type	LPDDR4
	Frequency [MHz]	1600
	Bus witdth [bit]	32
	Theoretical bandiwidth [Gb/s]	102.4
	Size [MB]	3072

Software configuration

• Linux kernel: 4.14.98
• Architecture: aarch64
• Governor: userspace @ 800 MHz

root@Mito8M:~# echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
root@Mito8M:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
userspace
root@Mito8M:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
800000

GCC

armbian@Mito8M:~/devel/lmbench$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/aarch64-linux-gnu/8/lto-wrapper
Target: aarch64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 8.3.0-6' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-8 --program-prefix=aarch64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libquadmath --disable-libquadmath-support --enable-plugin --enable-default-pie --with-system-zlib --disable-libphobos --enable-multiarch --enable-fix-cortex-a53-843419 --disable-werror --enable-checking=release --build=aarch64-linux-gnu --host=aarch64-linux-gnu --target=aarch64-linux-gnu
Thread model: posix
gcc version 8.3.0 (Debian 8.3.0-6)

Results

This section details the results that were achieved by the different benchmarks

Testbed #1

		Mito8M
	ARM frequency [MHz]	792
	Frequency [MHz]	1600
	Bus witdth [bit]	32

Detailed testing procedures

This sections details how the benchmarks were configured and run on the testbed.

STREAM

Building

git clone https://github.com/jeffhammond/STREAM.git
make

 1 armbian@Mito8M:~/devel/STREAM$ cat Makefile 
 2 CC = gcc
 3 CFLAGS = -O2 -fopenmp
 4 
 5 FC = gfortran-4.9
 6 FFLAGS = -O2 -fopenmp
 7 
 8 all: stream_c.exe
 9 
10 stream_f.exe: stream.f mysecond.o
11         $(CC) $(CFLAGS) -c mysecond.c
12         $(FC) $(FFLAGS) -c stream.f
13         $(FC) $(FFLAGS) stream.o mysecond.o -o stream_f.exe
14 
15 stream_c.exe: stream.c
16         $(CC) $(CFLAGS) stream.c -o stream_c.exe
17 
18 clean:
19         rm -f stream_f.exe stream_c.exe *.o
20 
21 # an example of a more complex build line for the Intel icc compiler
22 stream.icc: stream.c
23         icc -O3 -xCORE-AVX2 -ffreestanding -qopenmp -DSTREAM_ARRAY_SIZE=80000000 -DNTIMES=20 stream.c -o stream.omp.AVX2.80M.20x.icc

Running

armbian@Mito8M:~/devel/STREAM$ ./stream_c.exe 
-------------------------------------------------------------
STREAM version $Revision: 5.10 $
-------------------------------------------------------------
This system uses 8 bytes per array element.
-------------------------------------------------------------
Array size = 10000000 (elements), Offset = 0 (elements)
Memory per array = 76.3 MiB (= 0.1 GiB).
Total memory required = 228.9 MiB (= 0.2 GiB).
Each kernel will be executed 10 times.
 The *best* time for each kernel (excluding the first iteration)
 will be used to compute the reported bandwidth.
-------------------------------------------------------------
Number of Threads requested = 4
Number of Threads counted = 4
-------------------------------------------------------------
Your clock granularity/precision appears to be 1 microseconds.
Each test below will take on the order of 46427 microseconds.
   (= 46427 clock ticks)
Increase the size of the arrays if this shows that
you are not getting at least 20 clock ticks per test.
-------------------------------------------------------------
WARNING -- The above is only a rough guideline.
For best results, please be sure you know the
precision of your system timer.
-------------------------------------------------------------
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:            6770.5     0.024010     0.023632     0.025117
Scale:           6093.2     0.027474     0.026259     0.029142
Add:             5263.5     0.046008     0.045597     0.046230
Triad:           4820.0     0.050297     0.049793     0.050723
-------------------------------------------------------------
Solution Validates: avg error less than 1.000000e-13 on all three arrays
-------------------------------------------------------------

Useful links

• STREAM benchmark
• LM Bench benchmark
• pmbw benchmark
• Joshua Wyatt Smith and Andrew Hamilton, Parallel benchmarks for ARM processors in the highenergy context
• T Wrigley, G Harmsen and B Mellado, Memory performance of ARM processors and itsrelevance to High Energy Physics
• G. T. Wrigley, R. G. Reed, B. Mellado, Memory benchmarking characterisation of ARM-based SoCs