Programming to Offload Image Processing on Android* Applications

Total Page:16

File Type:pdf, Size:1020Kb

Programming to Offload Image Processing on Android* Applications Programming to Offload Image Processing on Android* Applications 1 INTRODUCTION This article walks through an example Android application that offloads image processing using OpenCL™ and RenderScript programming languages. These programming languages are designed to take advantage of highly parallel graphics hardware (shaders) to compute large data sets and highly repetitive tasks. Although you can use other languages to offload image processing in Android applications, this article shows OpenCL and RenderScript sample code for developing application infrastructure and image processing algorithm code. The OpenCL API wrapper class is also shown and is used to facilitate programming and execution of OpenCL for image processing algorithms. The OpenCL API wrapper class source code is available license-free for anyone to use. You should be familiar with OpenCL, RenderScript, and Android programming concepts as this article only covers the instructions to offload image processing or media generation computes. You should also have an Android device that is equipped, enabled, and configured to run OpenCL (refer to Intel® SDK for OpenCL for Android device installation). Note: While other languages and techniques to offload image processing or media generation are available, here, the goal is to only highlight code differences. Future article is planned that will highlight performance differences between OpenCL and RenderScript executing on GPUs. 1.1 APPLICATION UI DESIGN In the sample application, the UI has three radio buttons so that users can quickly switch application execution between RenderScript, OpenCL, or native code. Another menu setting allows users to select whether to run OpenCL on the CPU or GPU. The menu also gives users the list of implemented effects to run, so they can select the effect they want to run. Selecting a device only applies to OpenCL (not RenderScript or native code). Intel® x86 platforms include OpenCL runtime support on both CPU and GPU. Below is a screenshot of the main UI which shows a version of the plasma effect being processed by OpenCL. The sample application UI shows performance results when running OpenCL, RenderScript, or native code. Settings Menu The performance metrics include frame per second (fps), frame render, and effect compute elapsed time. The performance metrics are highlighted in the screenshot below. Note that performance numbers shown on the screen capture are sample metrics; actual performance metrics will vary depending on the device. 1.2 APIS AND SDKS In addition to the ADT (Android Development Tool which also includes the Android SDK), the main Android based APIs utilized to program the sample application are RenderScript and Intel® SDK for OpenCL for Android applications. The Intel OpenCL™ SDK is based on and adheres to the OpenCL™ specification which is an open, royalty- free standard for cross-platform programming. For more details, refer to the OpenCL™ standard from the Khronos web site. RenderScript first became available in 2.2 ADT (API Level 8) and is a framework for running compute- intensive tasks on Android. RenderScript is primarily oriented for use with data-parallel computations, although serial computational workloads can benefit as well. Refer to the Android developer site for more information. The latest ADT available from Google’s open source repository includes the appropriate packages that need to be imported to use RenderScript, JNI (Java* Native Interface), and runtime APIs. For OpenCL setup, configuration, and runtime refer to this OpenCL Development for Android OS article. For additional programming details see RenderScript or OpenCL. 1.3 INFRASTRUCTURE CODE The infrastructure code consists of the “main” activity and helper functions. This section highlights helper functions and code for setting up the UI, selecting which effect and language technology to run, and, for OpenCL, which compute device to use. While several helper functions were implemented to integrate the user selection commands, only two are highlighted here: The backgroundThread() helper function starts a thread that periodically calls the step process function to process image effects. The code and functionality used in this function is reused from another sample application posted in the Getting Started with RenderScript article, and you can find further details here (PDF). The processStep() function is called by the backgroundThread() to process and run the image effects. The function relies on a radio button callback function to determine which language to use. The processStep() function invokes the appropriate method to process the image effect using OpenCL, RenderScript, or plain native C/C++ code. Since this code runs on a background thread, users can select a language to run by simply clicking or touching a radio button, even while an effect is being processed. The application dynamically switches to execute the appropriate step render function for a given image effect. // The processStep() method runs in a separate (background) thread. private void processStep() { try { switch (this.type.getCheckedRadioButtonId()) { case R.id.type_renderN: oclFlag = 0; // OpenCL is OFF stepRenderNative(); break; case R.id.type_renderOCL: oclFlag = 1; // OpenCL is ON stepRenderOpenCL(); break; case R.id.type_renderRS: oclFlag = 0; // OpenCL is OFF stepRenderScript(); break; default: return; } } catch (RuntimeException ex) { // Handle exception as appropriate and log error Log.wtf("Android Image Processing", "render failed", ex); } } 1.4 JAVA DEFINITION OF NATIVE FUNCTIONS The sample application implements a NativeLib class, which primarily defines functions that call into the native functionality through JNI to process a given effect. For instance, the sample application implements three effects: plasma, sepia, and monochrome. As such, the class defines the renderPlasma(…), renderSepia(…), and renderMonoChrome(…) functions. These Java functions serve as entry points through JNI to either run native or OpenCL functionality. The JNI function executes either C/C++ code or sets up and executes the OpenCL program that implements the image effect. The class uses Android bitmap and AssetManager packages. The BitMap objects are utilized to pass and return data for the image or media being processed. The application relies on the AssetManager object to gain access to the OpenCL files (i.e., sepia.cl) where the OpenCL kernels are defined. Below is the actual NativeLib Java class definition. The //TODO comment is included to illustrate that the application can be easily extended to implement additional image effects. package com.example.imageprocessingoffload; import android.content.res.AssetManager; import android.graphics.Bitmap; public class NativeLib { // Implemented in libimageeffects.so public static native void renderPlasma(Bitmap bitmapIn, int renderocl, long time_ms, String eName, int devtype, AssetManager mgr); public static native void renderMonoChrome(Bitmap bitmapIn, Bitmap bitmapOut, int renderocl, long time_ms, String eName, int simXtouch, int simYtouch, int radHi, int radLo, int devtype, AssetManager mgr); public static native void renderSepia(Bitmap bitmapIn, Bitmap bitmapOut, int renderocl, long time_ms, String eName, int simXtouch, int simYtouch, int radHi, int radLo, int devtype, AssetManager mgr); //TODO public static native <return type> render<Effectname>(…); //load actual native library static { System.loadLibrary("imageeffectsoffloading"); } } Note that the Android AssetManager and BitMap objects are passed for image input and image results to the native code. The AssetManager object is used by native code to be able to access CL files where the OpenCL kernels are defined. The BitMap object is used to make pixel data available for native code to compute and produce image results. The UI parameter deviceType is used to indicate whether to execute OpenCL on the CPU or the GPU. The Android system must be configured and capable of running OpenCL on both devices. Modern Intel® Atom™ and Intel® Core™ processors can run OpenCL on the CPU and the integrated graphics processor or GPU. The eName parameter is passed to indicate which OpenCL kernel to compile and run. Although the sample application implements a JNI function per image effect, this might appear unnecessary. However, it is possible to define multiple related image effects in a single CL file and/or JNI function. In such cases the eName would be used to compile and load the appropriate CL program and/or kernel. The renderocl parameter is used as a flag that indicates whether to run OpenCL or native C/C++ code. This flag is only set when a user selects the OpenCL radio button; otherwise, it remains unset. The time_ms parameter is used to pass a time stamp (milliseconds), which is used to calculate the performance metrics. In the plasma effect the time stamp is used to calculate the plasma effect stepping. Other arguments are specific to the image effect algorithm to render the effect radially from the center of the image. For example, the simXtouch, simYtouch, radLo, and radHi parameters along with the width and height are used to calculate and show radial progress of the monochrome and sepia effects. 1.5 DEFINITIONS AND RESOURCES TO RUN NATIVE CODE (C OR OPENCL) This section includes the JNI native function definitions for each effect implemented in the sample application. As previously mentioned, one function per effect is utilized to simplify the explanation and illustrate the functional elements used to offload image effect
Recommended publications
  • AVG Android App Performance and Trend Report H1 2016
    AndroidTM App Performance & Trend Report H1 2016 By AVG® Technologies Table of Contents Executive Summary .....................................................................................2-3 A Insights and Analysis ..................................................................................4-8 B Key Findings .....................................................................................................9 Top 50 Installed Apps .................................................................................... 9-10 World’s Greediest Mobile Apps .......................................................................11-12 Top Ten Battery Drainers ...............................................................................13-14 Top Ten Storage Hogs ..................................................................................15-16 Click Top Ten Data Trafc Hogs ..............................................................................17-18 here Mobile Gaming - What Gamers Should Know ........................................................ 19 C Addressing the Issues ...................................................................................20 Contact Information ...............................................................................21 D Appendices: App Resource Consumption Analysis ...................................22 United States ....................................................................................23-25 United Kingdom .................................................................................26-28
    [Show full text]
  • ART Vs. NDK Vs. GPU Acceleration: a Study of Performance of Image Processing Algorithms on Android
    DEGREE PROJECT IN COMPUTER SCIENCE AND ENGINEERING, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2017 ART vs. NDK vs. GPU acceleration: A study of performance of image processing algorithms on Android ANDREAS PÅLSSON KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF COMPUTER SCIENCE AND COMMUNICATION ART vs. NDK vs. GPU acceleration: A study of performance of image processing algorithms on Android ANDREAS PÅLSSON Master in Computer Science Date: June 26, 2017 Supervisor: Cyrille Artho Examiner: Johan Håstad Swedish title: ART, NDK eller GPU acceleration: En prestandastudie av bildbehandlingsalgoritmer på Android School of Computer Science and Communication iii Abstract The Android ecosystem contains three major platforms for execution suit- able for different purposes. Android applications are normally written in the Java programming language, but computationally intensive parts of An- droid applications can be sped up by choosing to use a native language or by utilising the parallel architecture found in graphics processing units (GPUs). The experiments conducted in this thesis measure the performance benefits by switching from Java to C++ or RenderScript, Google’s GPU acceleration framework. The experiments consist of often-done tasks in image processing. For some of these tasks, optimized libraries and implementations already exist. The performance of the implementations provided by third parties are compared to our own. Our results show that for advanced image processing on large images, the benefits are large enough to warrant C++ or RenderScript usage instead of Java in modern smartphones. However, if the image processing is conducted on very small images (e.g. thumbnails) or the image processing task contains few calculations, moving to a native language or RenderScript is not worth the added development time and static complexity.
    [Show full text]
  • Embedded Android
    www.it-ebooks.info www.it-ebooks.info Praise for Embedded Android “This is the definitive book for anyone wanting to create a system based on Android. If you don’t work for Google and you are working with the low-level Android interfaces, you need this book.” —Greg Kroah-Hartman, Core Linux Kernel Developer “If you or your team works on creating custom Android images, devices, or ROM mods, you want this book! Other than the source code itself, this is the only place where you’ll find an explanation of how Android works, how the Android build system works, and an overall view of how Android is put together. I especially like the chapters on the build system and frameworks (4, 6, and 7), where there are many nuggets of information from the AOSP source that are hard to reverse-engineer. This book will save you and your team a lot of time. I wish we had it back when our teams were starting on the Frozen Yogurt version of Android two years ago. This book is likely to become required reading for new team members working on Intel Android stacks for the Intel reference phones.” —Mark Gross, Android/Linux Kernel Architect, Platform System Integration/Mobile Communications Group/Intel Corporation “Karim methodically knocks out the many mysteries Android poses to embedded system developers. This book is a practical treatment of working with the open source software project on all classes of devices, beyond just consumer phones and tablets. I’m personally pleased to see so many examples provided on affordable hardware, namely BeagleBone, not just on emulators.” —Jason Kridner, Sitara Software Architecture Manager at Texas Instruments and cofounder of BeagleBoard.org “This book contains information that previously took hundreds of hours for my engineers to discover.
    [Show full text]
  • A Scalable and Reliable Mobile Code Offloading Solution
    Hindawi Wireless Communications and Mobile Computing Volume 2018, Article ID 8715294, 18 pages https://doi.org/10.1155/2018/8715294 Research Article MobiCOP: A Scalable and Reliable Mobile Code Offloading Solution José I. Benedetto ,1 Guillermo Valenzuela ,1 Pablo Sanabria,1 Andrés Neyem ,1 Jaime Navón,1 and Christian Poellabauer 2 1 Computer Science Department, Pontifcia Universidad Catolica´ de Chile, Santiago, Chile 2Computer Science and Engineering Department, University of Notre Dame, Notre Dame, IN, USA Correspondence should be addressed to Jose´ I. Benedetto; [email protected] Received 26 September 2017; Accepted 12 December 2017; Published 9 January 2018 Academic Editor: Konstantinos E. Psannis Copyright©2018Jose´ I. Benedetto et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Code ofoading is a popular technique for extending the natural capabilities of mobile devices by migrating processor-intensive tasks to resource-rich surrogates. Despite multiple platforms for ofoading being available in academia, these frameworks have yet to permeate the industry. One of the primary reasons for this is limited experimentation in practical settings and lack of reliability, scalability, and options for distribution. Tis paper introduces MobiCOP, a new code ofoading framework designed from the ground up with these requirements in mind. It features a novel design fully self-contained in a library and ofers compatibility with most stock Android devices available today. Compared to local task executions, MobiCOP ofers performance improvements of up to 17x and increased battery efciency of up to 25x, shows minimum performance degradation in environments with unstable networks, and features an autoscaling module that allows its server counterpart to scale to an arbitrary number of ofoading requests.
    [Show full text]
  • Performance Analysis of Mobile Applications Developed with Different Programming Tools
    MATEC Web of Conferences 252, 05022 (2019) https://doi.org/10.1051/matecconf/201925205022 CMES’18 Performance analysis of mobile applications developed with different programming tools Jakub Smołka1,*, Bartłomiej Matacz2, Edyta Łukasik1, and Maria Skublewska-Paszkowska1 1Lublin University of Technology, Electrical Engineering and Computer Science Faculty, Institute of Computer Science, Nadbystrzycka 36b, 20-618 Lublin, Poland 2 Cybercom, Hrubieszowska 2, 01-209 Warsaw, Poland Abstract. This study examines the efficiency of certain software tasks in applications developed using three frameworks for the Android system: Android SDK, Qt and AppInventor. The results obtained using the Android SDK provided the benchmark for comparison with other frameworks. Three test applications were implemented. Each of them had the same functionality. Performance in the following aspects was tested: sorting a list of items using recursion by means of the Quicksort algorithm, access time to a location from a GPS sensor, duration time for reading the entire list of phone contacts, saving large and small files, reading large and small files, image conversion to greyscale, playback time of a music file, including the preparation time. The results of the Android SDK are good. Unexpectedly, it is not the fastest tool, but the time for performing most operations can be considered satisfactory. The Qt framework is overall about 34% faster than the Android SDK. The worst in terms of overall performance is the AppInventor: it is, on average, over 626 times slower than Android SDK. 1 Introduction The third part presents the results, which are then analysed. According to a recent study [1], the number of As already mentioned, currently the most popular smartphone users is forecasted to grow from 2.1 billion system for mobile devices is Android.
    [Show full text]
  • Renderscript Basic Tutorial for Android* OS
    RenderScript Basic Tutorial for Android* OS User's Guide Compute Code Builder - Samples Document Number: 330186-002US Android RenderScript Tutorial Contents Contents ......................................................................................................................... 2 Legal Information ............................................................................................................ 3 Introduction .................................................................................................................... 4 What is RenderScript? ...................................................................................................... 4 Running and Controlling the Tutorial .................................................................................. 4 RenderScript Java* APIs ................................................................................................... 5 RenderScript Kernels ........................................................................................................ 7 Tutorial Application Structure ............................................................................................ 8 Seperating RenderScript Kernel and UI Thread Executions .................................................... 8 Android Application Lifecycle Events ................................................................................... 8 Limitations ...................................................................................................................... 9 Notes on Threading
    [Show full text]
  • Renderscript Lecture 10
    Renderscript Lecture 10 Android Native Development Kit 6 May 2014 NDK Renderscript, Lecture 10 1/41 RenderScript RenderScript Compute Scripts RenderScript Runtime Layer Reflected Layer Memory Allocation Bibliography Keywords NDK Renderscript, Lecture 10 2/41 Outline RenderScript RenderScript Compute Scripts RenderScript Runtime Layer Reflected Layer Memory Allocation Bibliography Keywords NDK Renderscript, Lecture 10 3/41 Android NDK I NDK - perform fast rendering and data-processing I Lack of portability I Native lib that runs on ARM won't run on x86 I Lack of performance I Hard to identify (CPU/GPU/DSP) cores and run on them I Deal with synchronization I Lack of usability I JNI calls may introduce bugs I RenderScript developed to overcome these problems NDK Renderscript, Lecture 10 4/41 RenderScript I Native app speed with SDK app portability I No JNI needed I Language based on C99 - modern dialect of C I Pair of compilers and runtime I Graphics engine for fast 2D/3D rendering I Deprecated from Android 4.1 I Developers prefer OpenGL I Compute engine for fast data processing I Running threads on CPU/GPU/DSP cores I Compute engine only on CPU cores NDK Renderscript, Lecture 10 5/41 RenderScript Architecture I Android apps running in the Dalvik VM I Graphics/compute scripts run in the RenderScript runtime I Communication between them through instances of reflected layer classes I Classes are wrappers around the scripts I Generated using the Android build tools I Eliminate the need of JNI I Memory management I App allocated memory I Memory
    [Show full text]
  • Android™ Hacker's Handbook
    ffi rs.indd 01:50:14:PM 02/28/2014 Page ii Android™ Hacker’s Handbook ffi rs.indd 01:50:14:PM 02/28/2014 Page i ffi rs.indd 01:50:14:PM 02/28/2014 Page ii Android™ Hacker’s Handbook Joshua J. Drake Pau Oliva Fora Zach Lanier Collin Mulliner Stephen A. Ridley Georg Wicherski ffi rs.indd 01:50:14:PM 02/28/2014 Page iii Android™ Hacker’s Handbook Published by John Wiley & Sons, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2014 by John Wiley & Sons, Inc., Indianapolis, Indiana ISBN: 978-1-118-60864-7 ISBN: 978-1-118-60861-6 (ebk) ISBN: 978-1-118-92225-5 (ebk) Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or autho- rization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions. Limit of Liability/Disclaimer of Warranty: The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifi cally disclaim all warranties, including without limitation warranties of fi tness for a particular purpose.
    [Show full text]
  • Performance Portability for Embedded Gpus
    Performance Portability for Embedded GPUs Simon McIntosh-Smith [email protected] Head of Microelectronics Research University of Bristol, UK 1 ! GPUcompute on Embedded GPUs Simon McIntosh-Smith [email protected] Head of Microelectronics Research University of Bristol, UK 2 ! ! " Embedded GPUs becoming monsters Average Moore’s Law = 2x/2yrs 2x/3yrs 6-7B transistors 2x/2yrs ~1-2B transistors High-performance MPU, e.g. Apple's 2013 A7 Intel Nehalem processor is over 1B transistors in 102mm2 Cost-performance MPU, e.g. Nvidia Tegra http://www.itrs.net/Links/2011ITRS/2011Chapters/2011ExecSum.pdf 3 ! " Programmable embedded GPUs go mainstream in 2014 •" Lots of significant announcements recently (at CES etc) •" Imagination Series 6XT (Rogue) GPU •" ARM Mali T760 •" Qualcomm Adreno 420 •" AMD Radeon E6XXX (576 GFLOPS), Kaveri •" Intel IRIS •" Vivante GC7000 series •" Nvidia Tegra K1 •" Other vendors too: Broadcom, … •" 2014 is the year that OpenCL programmable embedded GPUs will become ubiquitous 4 ! "Architectural trends •" Integrated CPU/GPU with shared virtual memory and cache coherency •" SVM is a key new feature of OpenCL 2.0 •" Efficiency improvements in overheads for launching tasks/kernels •" Promotes finer-grained heterogeneous parallel programs •" Supported by OpenCL 2.0 subgroups and nested (dynamic) parallelism •" Heterogeneous Systems Architecture (HSA) etc 5 ! "Where are we now? •" Usefully (OpenCL) programmable GPUs just starting to become available •" OpenCL 2.0, SPIR and HSA will enable much greater efficiency in the exploitation
    [Show full text]
  • Intel® Technology Journal | Volume 18, Issue 2, 2014
    Intel® Technology Journal | Volume 18, Issue 2, 2014 Publisher Managing Editor Content Architect Cory Cox Stuart Douglas Paul Cohen Program Manager Technical Editor Technical Illustrators Paul Cohen David Clark MPS Limited Technical and Strategic Reviewers Bruce J Beare Tracey Erway Michael Richmond Judi A Goldstein Kira C Boyko Miao Wei Paul De Carvalho Ryan Tabrah Prakash Iyer Premanand Sakarda Ticky Thakkar Shelby E Hedrick Intel® Technology Journal | 1 Intel® Technology Journal | Volume 18, Issue 2, 2014 Intel Technology Journal Copyright © 2014 Intel Corporation. All rights reserved. ISBN 978-1-934053-63-8, ISSN 1535-864X Intel Technology Journal Volume 18, Issue 2 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4744. Requests to the Publisher for permission should be addressed to the Publisher, Intel Press, Intel Corporation, 2111 NE 25th Avenue, JF3-330, Hillsboro, OR 97124-5961. E-Mail: [email protected]. Th is publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in professional services. If professional advice or other expert assistance is required, the services of a competent professional person should be sought.
    [Show full text]
  • Optimizing Android in the ARM Ecosystem [email protected] ARM Strategic Software Alliances
    Optimizing Android in the ARM Ecosystem [email protected] ARM Strategic Software Alliances 1 ARM Engineering Global Coverage [email protected] 2 ARM Android Ecosystem Strategy § Deliver value throughout the growing Ecosystem § Make it easy for ARM Silicon Partners to Deliver Android § Off-the-shelf ARM Processor/Board ports and recipes § Make Android better on ARM for OEM’s § Optimize Key Open Source ingredients § Engage Developers in use of advanced ARM Tech § Blog Posts, Webinars § Tools, Libraries § Developer Knowledge Sites § Developer Relations 3 ARM Android Ecosystem Strategy § Deliver value throughout the growing Ecosystem § Make it easy for ARM Silicon Partners to Deliver Android § Off-the-shelf ARM Processor/Board ports and recipes § Make Android better on ARM for OEM’s § Optimize Key Open Source ingredients § Engage Developers in use of advanced ARM Tech § Blog Posts, Webinars § Tools, Libraries § Developer Knowledge Sites § Developer Relations 4 Android Boot Recipe for new ARM SoC’s § ARM brings the latest Android releases up on latest SoC’s § “From Zero to Boot” Recipe Blog Post § ARM Partners can easily apply recipe to their SoC § Typical bring-up times are in the order of a few days! 5 Android Bring-Up on ARM SoC’s Info § From Zero to Boot recipe § http://blogs.arm.com/software-enablement/498-from-zero-to-boot-porting-android- to-your-arm-platform/ § Building Android for ARM Boards - Existing ports description § http://linux-arm.org/LinuxKernel/LinuxAndroidPlatform § Git repos - existing ports § Linux Kernel and Android
    [Show full text]
  • Phase-Based Accurate Power Modeling for Mobile Application Processors
    electronics Article Phase-Based Accurate Power Modeling for Mobile Application Processors Kitak Lee 1,2 , Seung-Ryeol Ohk 1, Seong-Geun Lim 1 and Young-Jin Kim 1,* 1 Department of Electrical and Computer Engineering, Ajou University, Suwon 16499, Korea; [email protected] (K.L.); [email protected] (S.-R.O.); [email protected] (S.-G.L.) 2 System LSI Business, Samsung Electronics Co., Ltd., Hwaseong 18448, Korea * Correspondence: [email protected] Abstract: Modern mobile application processors are required to execute heavier workloads while the battery capacity is rarely increased. This trend leads to the need for a power model that can analyze the power consumed by CPU and GPU at run-time, which are the key components of the application processor in terms of power savings. We propose novel CPU and GPU power models based on the phases using performance monitoring counters for smartphones. Our phase-based power models employ combined per-phase power modeling methods to achieve more accurate power consumption estimations, unlike existing power models. The proposed CPU power model shows estimation errors of 2.51% for ARM Cortex A-53 and 1.97% for Samsung M1 on average, and the proposed GPU power model shows an average error of 8.92% for the Mali-T880. In addition, we integrate proposed CPU and GPU models with the latest display power model into a holistic power model. Our holistic power model can estimate the smartphone0s total power consumption with an error of 6.36% on average while running nine 3D game benchmarks, improving the error rate by about 56% compared with the latest prior model.
    [Show full text]