Research on Parallel Programming Language Elixir on MPSoC, and Real Time, High Resolution Satellite Image Processing Susumu Yamazaki Univ. of Kitakyushu 1 © 2021 Susumu Yamazaki

For Disasters • Disasters caused by global warming, climate variability and extreme weather will lead to enormous human and economic losses. • So, our laboratory at University of Kitakyushu has the following two research directions: 1. Eliminate computer device power consumption 2. Realize disaster detecting system using satellites 2 © 2021 Susumu Yamazaki no, CC BY-SA 4.0, via Wikimedia Commons

Eliminate computer device power consumption 3 © 2021 Susumu Yamazaki

Computer device power consumption • A. Andrae & T. Edler: On Global Electricity Usage of Communication Technology: Trends to 2030, Challenges 2015, 6(1), 117-157. • Power consumption of computer devices related to communication technology is • 21% of global power supply in the Expected average case as of 2030 • 51% of global electricity supply in the Worst Case expected in 2030 • Combined with other materials, it seems that as of 2020, the scenario is the Expected scenario shown on the right. 4 © 2020 Susumu Yamazaki © "OESBFBOE&EMFS

© 2020 Susumu Yamazaki Computers and global warming are by no means unrelated ˜)PXBSE+ ˜4VTVNV:BNB[BLJ

Energy Consumption of Transistors • Hennessy, J. L. and Patterson, D. A.: Computer Architecture: A Quantitative Approach, Morgan Kaufmann, 6th edition (2017). • Energy consumption of transistors is in proposition to • A square of voltage • The numbers of transistors • The clock frequency • Higher clock frequency requires higher voltage • Because lower voltage causes more time of turning on and off the switch of transistors 6 © 2021 Susumu Yamazaki

How can software eliminate energy consumption? • The following approaches are effective to eliminate the energy consumption: • Keep lower voltage by keeping lower clock frequency: • Eliminate clock cycles to achieve the function • Parallelize the software and eliminate redundant synchronization • Keep less the numbers of the transistors that are turn on • Turn off the clock of the module 7 © 2021 Susumu Yamazaki

Computer Units in Lower Energy Consumption by MPSoC • MPSoC: Multiple Processor System on Chip • Recent MPSoC is integrated with not only cores of CPU but also GPU and FPGA. • Processors in smart phones and Apple M1 chips are MPSoC • Computer units with MPSoC consumes lower energy and has higher performance. • The measurement results of the right two kind of computer units: • Standby power consumption is 3 Watt hour • Power consumption in case that CPU runs on full power is 17 Watt hour • Maximum power consumption at spec is 30 Watt hour • 100 computer units will consume only 3 kilo Watt hour, which is as much as air-conditioner for business. • In order to drive 100 computers units, parallelization will be more important. 8 © 2021 Susumu Yamazaki © 2018 NVIDIA © 2020 Apple

Elixir is a drastic solution to parallelize software • Suppose some data are shared with some cores. • If a core updates the shared data, • Then it notifies other cores, and they stop processing. • It causes slow down. • If there are many cores, waiting time grows exponentially. • Elixir is immutable, that is, it forbids all updates of shared data. • So, the other cores don’t need to stop processing. 9 © 2021 Susumu Yamazaki 4IBSFE%BUB $PSF #1 $PSF2 3.14 4IBSFE%BUB $PSF #1 $PSF2 3.14 →1.5 6QEBUF /PUJGZ 4UPQ1SPDFTTJOH 4IBSFE%BUB $PSF #1 $PSF2 3.14 %PO`U 6QEBUF %PO`UOFFEUP TUPQQSPDFTTJOH

Elixir with JIT • Recent Elixir has a Just-in-time compiler (JIT), which compiles byte code into native code during running. • JIT can eliminate clock cycles of running Elixir because it generates native code, which requires less clock cycles. • Our research interests is to implement JIT that generates more efficient native code. 10 © 2021 Susumu Yamazaki

Realize disaster detecting system using satellites 11 © 2021 Susumu Yamazaki

SAR Satellites? • SAR: Synthetic Aperture Radar • They observe the Earth’s surface by microwave (see the right figure), not by radiant rays. • Because SAR is an active sensor unlike an optical passive sensor, they can observe the Earth’s surface even at nighttime when the sun doesn’t reach. • Microwave transmitted by them also passes through even cloud unlike radiant rays. 12 © 2020 Susumu Yamazaki © CRISP, 2001 ©2021 iQPS

What apps will be expected? • Disaster preparation and recovery • Harvest predictions • Economic predictions • Natural environment protection and observation • Physical distribution management • Searching for mineral resources • And so on. 13 © 2020 Susumu Yamazaki

How serious is a menace of flood damage? 14 © 2021 Susumu Yamazaki

A Menace of Flood Damage 15 © 2021 Susumu Yamazaki This is the street view of Toho small town, Fukuoka, Japan, when the flood damage of a very heavy outbreak of rain that poured in west Japan in 2017, which forced us to pay 536,000,000,000 Yen (about 5 billion dollars). You can see this at https://goo.gl/maps/eM6cpL4LpYBMyFig7

What can satellites support for solving to flood issues? 16 © 2021 Susumu Yamazaki

What can satellites support for solving to flood issues? We can find out where there might have been a landslide by following the steps: 1. Take pictures of places with potential heavy rainfall according to the weather forecast, before the heavy rainfall. 2. Take pictures of the places again, during and after the heavy rainfall. 3. Find image differences of the photos before and after the heavy rainfall. Very easy! All we have to do is to do it in time. 17 © 2021 Susumu Yamazaki

We need more POWER! 18 © 2021 Susumu Yamazaki

Elixir with JIT on MPSoC will bring more Power! 19 © 2021 Susumu Yamazaki © 2018 NVIDIA © 2020 Apple 4IBSFE%BUB $PSF #1 $PSF2 3.14 4IBSFE%BUB $PSF #1 $PSF2 3.14 →1.5 6QEBUF /PUJGZ 4UPQ1SPDFTTJOH 4IBSFE%BUB $PSF #1 $PSF2 3.14 %PO`U 6QEBUF %PO`UOFFEUP TUPQQSPDFTTJOH