The Theory and Implementation of DVFS on Linux

Jan 27, 2013Download as odp, pdf6 likes7,488 views

This document discusses power management techniques for Linux systems including static and dynamic power management. It describes implementing dynamic voltage and frequency scaling on Linux using the CPUfreq framework to dynamically adjust CPU frequency based on demand. It also discusses implementing these techniques on Intel XScale processors using the performance monitoring unit and a user-space application.

The Theory and
Implementation of DVFS on
Linux

Offline Optimization
Static Power Management (SPM)

Dynamic Power Management (DPM)
Online Optimization

Static Power Management (SPM)
System/Component
Level of Detail Evaluation
Under Test
RTL level Cycle-level simulation
CPU
Instruction level Instruction-level simulation

Hardware component level Functional simulation

System Software component level Monitoring tool

Hardware & Software
Complete system simulation
component level

Dynamic Power Management (DPM)
System/Component Under
Test (SUT/CUT) Implementation Level Methodology

DVS (Dynamic Voltage
CPU CPU and System software Scaling)

Low power mode of
System Components hardware operation

CVS (Coordinated Voltage
Cluster System CPU and System software Scaling)

Dynamic Power of CMOS Circuits Core Voltage

P ∝ fV 2

Clock Frequency

Dynamic Voltage and Frequency
Scaling (DVFS)

Framework of the Predictive User-Aware
Power Management

Kernel Module Governor Functionality

cpufreq_ondemand ondemand 按需求調節，不是很強大，但實現了動態頻率調節

cpufreq_powersave powersave 省電模式，通常以最低頻率運行，

cpufreq_userspace userspace 用戶模式，一些調頻工具軟件需要在此模式下才能運行

cpufreq_conservative conservative “ 保守”模式，類似於 ondemand ，但調整相對較緩

N/A performance 不降頻

Open Source
● https://github.com/pickerweng/syf-pwm

The document discusses the bootloaders for the BeagleBone Black system. It describes the memory organization and booting process, including the roles of the X-Loader and U-Boot bootloaders. The X-Loader is described as the first stage bootloader that is derived from U-Boot and runs in internal SRAM. It loads the second stage U-Boot bootloader. U-Boot is then described as the universal bootloader that can be ported to different boards with minimal changes and is responsible for loading the Linux kernel from external DDR memory.

Bootloaders (U-Boot) Omkar Rane

This document discusses bootloaders for embedded systems. It defines a bootloader as the first code executed after a system powers on or resets that is responsible for loading the operating system kernel. The document then describes the tasks of a bootloader like initializing hardware, loading binaries from storage, and providing a shell. It outlines the booting process differences between desktops and embedded systems. Finally, it focuses on the universal bootloader U-Boot, describing its directory structure, configuration, building process, and commands.

Uboot startup sequenceHoucheng Lin

U-boot provides a multistage boot process that initializes the CPU and board resources incrementally at each stage. It begins execution on the CPU in a limited environment and hands off to subsequent stages that gain access to more resources like memory and devices. U-boot supports booting an operating system image from storage like SSD or over the network and offers features like secure boot and hypervisor support.

USB DriversAnil Kumar Pugalia

The document discusses USB drivers and provides an overview of USB host and gadget subsystems in Linux. It describes USB host and gadget device driver types, registration processes, data structures used, and key functions for interacting with USB controllers, the USB core, and endpoints. The document outlines views of the USB host and gadget subsystems and how drivers interface with lower-level USB controller drivers and higher-level user applications through the USB core.

U Boot or Universal BootloaderSatpal Parmar

The document provides an overview of Das U-Boot, a universal boot loader used to load operating systems and applications into memory on embedded systems. It discusses U-Boot's features such as its command line interface, ability to load images from different sources, and support for various architectures and boards. It also covers compiling and configuring U-Boot, as well as its basic command set and image support capabilities.

Embedded Linux on ARMEmertxe Information Technologies Pvt Ltd

WALT vs PELT : Redux - SFO17-307Linaro

Session ID: SFO17-307 Session Name: WALT vs PELT : Redux - SFO17-307 Speaker: Pavan Kumar Kondeti Track: LMG ★ Session Summary ★ New data on the comparison of the WALT and PELT load tracking schemes in the scheduler --------------------------------------------------- ★ Resources ★ Event Page: http://connect.linaro.org/resource/sfo17/sfo17-307/ Presentation: Video: https://www.youtube.com/watch?v=r3QKEYpyetU --------------------------------------------------- ★ Event Details ★ Linaro Connect San Francisco 2017 (SFO17) 25-29 September 2017 Hyatt Regency San Francisco Airport --------------------------------------------------- Keyword: 'http://www.linaro.org' 'http://connect.linaro.org' --------------------------------------------------- Follow us on Social Media https://www.facebook.com/LinaroOrg https://twitter.com/linaroorg https://www.youtube.com/user/linaroorg?sub_confirmation=1 https://www.linkedin.com/company/1026961

Linux on ARM 64-bit ArchitectureRyo Jin

The document discusses Linux support for the ARM 64-bit (AArch64) architecture. It covers key aspects of the AArch64 instruction set like 64-bit registers and memory accesses. It describes the exception model with multiple privilege levels and modes for virtualization. It also summarizes the Linux kernel port to AArch64 including boot process, memory management support, and compatibility for 32-bit applications. Future work is outlined to improve platform support and add new features to the AArch64 version of Linux.

Embedded Linux on ARMEmertxe Information Technologies Pvt Ltd

Linux has emerged as a number one choice for developing OS based Embedded Systems. Open Source development model, Customizability, Portability, Tool chain availability are some reasons for this success. This course gives a practical perspective of customizing, building and bringing up Linux Kernel on an ARM based target hardware. It combines various previous modules you have learned, by combing Linux administration, Hardware knowledge, Linux as OS, C/Computer programming areas. After bringing up Linux, you can port any of the existing applications into the target hardware.

Introduction to char device driverVandana Salve

The document summarizes how to write a character device driver in Linux. It covers the anatomy of a device driver including the user interface via device files, and kernel interfaces via file operations and major/minor numbers. It describes registering a character driver by defining file operations, reserving major/minor numbers, and associating them. Open and release functions handle initialization and cleanup. Read/write functions transfer data between userspace and hardware. Ioctl allows extending functionality.

Secure Boot on ARM systems – Building a complete Chain of Trust upon existing...Linaro

Session ID: SFO17-200 Session Name: - SFO17-200 Speaker: Track: ★ Session Summary ★ --------------------------------------------------- ★ Resources ★ Event Page: http://connect.linaro.org/resource/sfo17/sfo17-200/ Presentation: Video: --------------------------------------------------- ★ Event Details ★ Linaro Connect San Francisco 2017 (SFO17) 25-29 September 2017 Hyatt Regency San Francisco Airport --------------------------------------------------- Keyword: http://www.linaro.org http://connect.linaro.org --------------------------------------------------- Follow us on Social Media https://www.facebook.com/LinaroOrg https://twitter.com/linaroorg https://www.youtube.com/user/linaroorg?sub_confirmation=1 https://www.linkedin.com/company/102696

Introduction to Modern U-BootGlobalLogic Ukraine

U-Boot is an open source bootloader used widely in embedded systems. It initializes hardware and loads the operating system kernel. The document provides an overview of U-Boot from the user and developer perspectives, including its features, build process, file structure, and boot sequence. It also discusses modernizing efforts like adopting the driver model, device tree, and Kbuild configuration system to improve compatibility and support new platforms.

Trusted firmware deep_dive_v1.0_Linaro

Linux Kernel Booting Process (1) - For NLKBshimosawa

Linux Device Tree艾鍗科技

The document discusses Linux device trees and how they are used to describe hardware configurations. Some key points: - A device tree is a data structure that describes hardware connections and configurations. It allows the same kernel to support different hardware. - Device trees contain nodes that represent devices, with properties like compatible strings to identify drivers. They describe things like memory maps, interrupts, and bus attachments. - The kernel uses the device tree passed by the bootloader to identify and initialize hardware. Drivers match based on compatible properties. - Device tree files with .dts extension can be compiled to binary blobs (.dtb) and overlays (.dtbo) used at boot time to describe hardware.

QemuKoganti Ravikumar

QEMU is a free and open-source hypervisor that performs hardware virtualization by emulating CPUs through dynamic binary translation and providing device models. This allows it to run unmodified guest operating systems. It can be used to create virtual machines similarly to VMWare, VirtualBox, KVM, and Xen. QEMU also supports emulating different CPU architectures and can save and restore the state of a virtual machine.

LCA14: LCA14-306: CPUidle & CPUfreq integration with schedulerLinaro

Embedded_Linux_BootingRashila Rr

The embedded Linux boot process involves multiple stages beginning with ROM code that initializes hardware and loads the first stage bootloader, X-Loader. The X-Loader further initializes hardware and loads the second stage bootloader, U-Boot, which performs additional initialization and loads the Linux kernel. The kernel then initializes drivers and mounts the root filesystem to launch userspace processes. Booting can occur from flash memory, an eMMC/SD card, over a network using TFTP/NFS, or locally via UART/USB depending on the boot configuration and available devices.

BeagleBone Black Booting ProcessSysPlay eLearning Academy for You

The document discusses the booting process of the BeagleBone Black. It begins with an overview of the PC and BeagleBone booting processes. It then covers booting through an SD card, including partitioning and creating a root filesystem. The document introduces bootloaders like U-Boot, describes serial booting, and how to add commands to U-Boot. It provides hands-on examples of bringing up the BeagleBone board from recovery.

I2C DriversSysPlay eLearning Academy for You

Linux power management: are you doing it right?Chris Simmonds

Devices operating on battery power need effective power management: anything you can do to reduce power usage will increase battery life. Even for devices running on mains power, better power managements has benefits in reducing the need for cooling and lower energy costs. This presentation describes the four principles of power management: don't rush if you don't have to; don't be ashamed of being idle; turn off things you are not using; and sleep when there is nothing else to do. Each of these has a counterpart in the Linux kernel.

LCU14-410: How to build an Energy Model for your SoCLinaro

LCU14-410: How to build an Energy Model for your SoC --------------------------------------------------- Speaker: Morten Rasmussen Date: September 18, 2014 --------------------------------------------------- ★ Session Summary ★ - ARM to provide a quick overview of the current energy model - Introduce the methodology/recipe used to build the energy model - Discuss ways in which the model is used today and intended next steps - Key outcomes: - Describe the - Identify gaps and limitations Summary of EAS workshop (Amit) -Summary of hacking sessions - plan to integrate Qualcomm-ARM-Linaro work to send upstream -Key outcomes: -List of features and responsibilities -Dependencies between upstreaming of features, if any --------------------------------------------------- ★ Resources ★ Zerista: http://lcu14.zerista.com/event/member/137778 Google Event: https://plus.google.com/u/0/events/ck3ti7eurknnsq0a4e9ks5a1sbs Video: https://www.youtube.com/watch?v=JfZt8W3NVgk&list=UUIVqQKxCyQLJS6xvSmfndLA Etherpad: http://pad.linaro.org/p/lcu14-410 --------------------------------------------------- ★ Event Details ★ Linaro Connect USA - #LCU14 September 15-19th, 2014 Hyatt Regency San Francisco Airport --------------------------------------------------- http://www.linaro.org http://connect.linaro.org

Online test program generator for RISC-V processorsRISC-V International

The document summarizes an online test program generator for RISC-V microprocessors called MicroTESK. It describes how the generator works offline by translating specifications into test programs, and online by executing directly on the device under test to generate and run tests. The generator uses techniques like combinatorial brute-force and randomization to generate diverse test cases and checks results with signatures and transformations to detect errors. Future work areas include supporting more RISC-V instruction subsets and advanced techniques like model-based generation, mutations, and equivalence checking.

Rootlinux17: Hypervisors on ARM - Overview and Design Choices by Julien Grall...The Linux Foundation

Hypervisors are used in a broad range of domains ranging from Embedded systems, Automotive to big iron servers. The choice of hypervisor has a strong impact on the overall design of your project and its performance. This talk introduces the state of virtualization on ARM, and provides a description of three popular open source hypervisors: KVM, Jailhouse and Xen. Julien Grall explains respective key features, technical differences and suitability of the hypervisor for different application domains. Julien Grall is a Software Virtualisation Engineer at ARM. The talk was delivered at Root Linux Conference 2017. Learn more: http://linux.globallogic.com/materials. The video recording is available at https://www.youtube.com/watch?v=jZNXtqFJpuc

Arm device tree and linux device driversHoucheng Lin

This document discusses how the Linux kernel supports different ARM boards using a common source code base. It describes how device tree is used to describe hardware in a board-agnostic way. The kernel initializes machine-specific code via the device tree and initializes drivers by matching compatible strings. This allows a single kernel binary to support multiple boards by abstracting low-level hardware details into the device tree rather than the kernel source. The document also contrasts the ARM approach to the x86 approach, where BIOS abstraction and standardized buses allow one kernel to support most x86 hardware.

Browsing Linux Kernel SourceMotaz Saad

Power managementScott Shu

Android power managementJerrin George

The document discusses Android power management and compares it to Linux power management and other standards like APM and ACPI. It describes how Android builds upon Linux power management by adding additional states and mechanisms like wake locks. Wake locks allow applications to prevent the device from sleeping by keeping the CPU powered on. The document outlines the different types of wake locks and how they control screen, CPU and other power states. It explains how wake locks are managed between the kernel and Java layers in Android and the flows when wake locks are acquired and released.

More Related Content

What's hot (20)

WALT vs PELT : Redux - SFO17-307Linaro

Linux on ARM 64-bit ArchitectureRyo Jin

Embedded Linux on ARMEmertxe Information Technologies Pvt Ltd

Introduction to char device driverVandana Salve

Secure Boot on ARM systems – Building a complete Chain of Trust upon existing...Linaro

Introduction to Modern U-BootGlobalLogic Ukraine

Trusted firmware deep_dive_v1.0_Linaro

Linux Kernel Booting Process (1) - For NLKBshimosawa

Linux Device Tree艾鍗科技

QemuKoganti Ravikumar

LCA14: LCA14-306: CPUidle & CPUfreq integration with schedulerLinaro

Embedded_Linux_BootingRashila Rr

BeagleBone Black Booting ProcessSysPlay eLearning Academy for You

I2C DriversSysPlay eLearning Academy for You

Linux power management: are you doing it right?Chris Simmonds

LCU14-410: How to build an Energy Model for your SoCLinaro

Online test program generator for RISC-V processorsRISC-V International

Rootlinux17: Hypervisors on ARM - Overview and Design Choices by Julien Grall...The Linux Foundation

Arm device tree and linux device driversHoucheng Lin

Browsing Linux Kernel SourceMotaz Saad

WALT vs PELT : Redux - SFO17-307Linaro

Linux on ARM 64-bit ArchitectureRyo Jin

Embedded Linux on ARMEmertxe Information Technologies Pvt Ltd

Introduction to char device driverVandana Salve

Secure Boot on ARM systems – Building a complete Chain of Trust upon existing...Linaro

Introduction to Modern U-BootGlobalLogic Ukraine

Trusted firmware deep_dive_v1.0_Linaro

Linux Kernel Booting Process (1) - For NLKBshimosawa

Linux Device Tree艾鍗科技

QemuKoganti Ravikumar

LCA14: LCA14-306: CPUidle & CPUfreq integration with schedulerLinaro

Embedded_Linux_BootingRashila Rr

BeagleBone Black Booting ProcessSysPlay eLearning Academy for You

I2C DriversSysPlay eLearning Academy for You

Linux power management: are you doing it right?Chris Simmonds

LCU14-410: How to build an Energy Model for your SoCLinaro

Online test program generator for RISC-V processorsRISC-V International

Rootlinux17: Hypervisors on ARM - Overview and Design Choices by Julien Grall...The Linux Foundation

Arm device tree and linux device driversHoucheng Lin

Browsing Linux Kernel SourceMotaz Saad

Viewers also liked (20)

Power managementScott Shu

Android power managementJerrin George

Power Management from Linux Kernel to AndroidNational Cheng Kung University

The document provides an overview of power management from Linux kernel to Android, covering introduction to Linux power management concepts, concepts behind Android power management, design and implementation details, and areas for potential improvements. It describes goals and approaches of Advanced Power Management (APM) and Advanced Configuration and Power Interface (ACPI) in Linux, and how Android power management is built as a slim wrapper on top of Linux power management, utilizing components like wake locks and different types of wake locks to control power state transitions.

SFO15-302: Energy Aware Scheduling: Progress UpdateLinaro

1. The document discusses introducing generic energy-awareness into the upstream Linux kernel through a new Energy Aware Scheduling (EAS) framework. 2. EAS aims to provide a common solution for scheduling tasks across different CPU topologies in a way that minimizes energy usage based on an energy model of the hardware. 3. The EAS framework integrates idle state, DVFS, and big.LITTLE support and is designed to be clean, based on measurable energy data, and support future CPU topologies with reduced software maintenance costs.

Power Management for the Nokia Internet Tabletsigor_stoppa_nokia

Mobile Application Development with JUCE and Native API’sAdam Wilson

This document discusses mixing JUCE components with native iOS and Android UI elements for mobile app development. It explains that JUCE was designed for desktop apps, not touchscreens, and lists some limitations. The solution presented is to use native platform APIs for scrollable lists, navigation, input, and databases, while using JUCE for audio processing, custom graphics, and specialized GUI elements. Advantages include familiar UIs, smooth scrolling, gesture support, and animation support from native APIs. Disadvantages include extra design and coding work. It then provides details on how to mix JUCE with native UI elements for Android and iOS, including modifying activities, passing data between languages, and integrating JUCE views into native view hierarchies.

LCA13: Who Disturbs My SlumberLinaro

This document discusses sources of wakeups that prevent ARM processors from entering idle states. It describes different types of interrupts like hardware interrupts, timers, and inter-processor interrupts. It provides details on how timers work and the different types of timers. It also explains the various inter-processor interrupts like those used for timer broadcasts, rescheduling, and function calls. Finally, it discusses ways to reduce the number of interrupts like using deferrable timers, rounding jiffies, and migrating work to non-idle CPUs.

Android framework design and developmentramalinga prasad tadepalli

The document discusses different categories of Android framework design and implementation. It describes: 1. Manager classes and framework services that can be implemented in Java or native C++ layers. 2. Interactions between Java manager classes and native C++ services using Binder callbacks, Ashmem for shared memory, and local sockets for communication. 3. Examples of native services like AudioFlinger and SurfaceFlinger that interact with hardware, and how they register and run as services.

Linaro Connect 2016 (BKK16) - Introduction to LISAPatrick Bellasi

LCA13: Power State Coordination InterfaceLinaro

Linux Power Management SlidesharePatrick Bellasi

Android Camera ArchitecturePicker Weng

Embedded Systems Power ManagementPatrick Bellasi

BUD17-309: IRQ prediction Linaro

"Session ID: BUD17-309 Session Name: IRQ prediction - BUD17-309 Speaker: Daniel Lezcano Track: Power Management ★ Session Summary ★ The CPUidle is one component of the power management framework. It behaves in an opportunistic way when there is nothing to do on the system, by trying to predict the next CPU wake up and select an idle state. But the current design has some weaknesses as it mixes the different sources of wakeup, resulting in an already non-deterministic situation getting worse. This presentation will describe the issues faced with the current approach and will show another approach to predict the next wake up event with a better accuracy, leading, under some circumstances, to 100% right predictions. --------------------------------------------------- ★ Resources ★ Event Page: http://connect.linaro.org/resource/bud17/bud17-309/ Presentation: https://www.slideshare.net/linaroorg/bud17309-irq-prediction Video: https://youtu.be/krFAyi1ietI --------------------------------------------------- ★ Event Details ★ Linaro Connect Budapest 2017 (BUD17) 6-10 March 2017 Corinthia Hotel, Budapest, Erzsébet krt. 43-49, 1073 Hungary --------------------------------------------------- Keyword: IRQ, power-management, CPUidle http://www.linaro.org http://connect.linaro.org --------------------------------------------------- Follow us on Social Media https://www.facebook.com/LinaroOrg https://twitter.com/linaroorg https://www.youtube.com/user/linaroorg?sub_confirmation=1 https://www.linkedin.com/company/1026961"

ResumeZundra Daniel

This document contains a summary and resume for Zundra Daniel, a senior software engineer with 12 years of experience designing scalable systems. They have worked at companies like Bluebox, IBM, and the Institute for Online Training. Their experience includes roles such as lead frontend engineer, cloud platform engineer, and senior software engineer. They have strong skills in languages like Ruby, JavaScript, Scala, and Java as well as technologies including React, AWS, and microservices.

Adapting the Lean Enterprise Self-Assessment Tool for Software Development Do...Teemu Karvonen

Presentation held at Euromicro 2012 SEAA (Izmir/Cesme Turkey) )conference for paper titled: Adapting the Lean Enterprise Self-assessment tool for software domain. ABSTRACT: Lean principles have attracted the attention of software development companies due to their potential to improve competitiveness. However, the application of such principles in the software domain is still in its infancy. This paper presents a proposal for adapting the Lean Enterprise Self-Assessment Tool (LESAT) to guide the transformation of software development companies toward Lean. LESAT, developed by the Lean Advancement Initiative (LAI) at the Massachusetts Institute of Technology (MIT), has been widely used in other domains. In this study, concepts and expressions of LESAT were analyzed and mapped to software development following the ISO/IEC 12207 standard. Seven assessment items concerning life-cycle processes were modified from the original LESAT. The modified LESAT for software was compared with a lean assessment approach called "Lean amplifier, " which has been developed and successfully used in practice by Ericsson R&D in Finland. The results indicated that LESAT may complement lean assessment in the software domain at enterprise level, involving the entire value stream. Moreover, they clearly emphasized the role of leadership in the transformation. http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6328160

Yesu Nallavar -Testimony of Sister NirmalaRaja Venkatesan

The document provides information about an upcoming event featuring E. Ephraim, a writer and speaker. 1) Ephraim will be presenting his works and videos on religion and spirituality. Videos can be purchased individually or in bundles. 2) Contact information is provided for two individuals coordinating the event for ordering materials or additional details. 3) A brief biography of Ephraim is given, noting his message aims to help people find inner peace through spiritual teachings.

Top 8 chief business development officer resume samplesporichfergu

The document provides information about resume samples and other career resources for chief business development officers. It lists top resume formats including chronological, functional, combination, targeted, curriculum vitae (CV), professional, new graduate, and executive resumes. It also provides links to interview questions, tips, thank you letters, cover letters, and other materials to help with the job search process for chief business development officer roles.

A V I D Juicy Ultimate Brake Bleedingradicallights

This document provides step-by-step instructions for bleeding Avid Juicy Ultimate disc brakes using a SRAM bleed kit. It describes preparing the syringes, caliper, and lever, then bleeding the caliper, hose, lever, and master cylinder. Tips are included for ensuring no air is introduced and for resetting the pads. The process aims to improve brake feel and consistency by removing air from the system.

Gutell 091.imb.2004.13.495Robin Gutell

This document presents a secondary structural model of expansion segments D2 and D3 from the 28S rRNA gene of 229 leaf beetles (Coleoptera: Chrysomelidae), most of which are in the subfamily Galerucinae. The model is based on a multiple sequence alignment that was analyzed to infer secondary structure based on compensatory base changes. The model consists of seven major compound helices and delineates conserved regions that can be confidently aligned versus regions of alignment ambiguity. This structural model of the D2 and D3 expansion segments will aid in assigning positional nucleotide homology and phylogenetic reconstruction for these and related beetle taxa.

Power managementScott Shu

Android power managementJerrin George

Power Management from Linux Kernel to AndroidNational Cheng Kung University

SFO15-302: Energy Aware Scheduling: Progress UpdateLinaro

Power Management for the Nokia Internet Tabletsigor_stoppa_nokia

Mobile Application Development with JUCE and Native API’sAdam Wilson

LCA13: Who Disturbs My SlumberLinaro

Android framework design and developmentramalinga prasad tadepalli

Linaro Connect 2016 (BKK16) - Introduction to LISAPatrick Bellasi

LCA13: Power State Coordination InterfaceLinaro

Linux Power Management SlidesharePatrick Bellasi

Android Camera ArchitecturePicker Weng

Embedded Systems Power ManagementPatrick Bellasi

BUD17-309: IRQ prediction Linaro

ResumeZundra Daniel

Adapting the Lean Enterprise Self-Assessment Tool for Software Development Do...Teemu Karvonen

Yesu Nallavar -Testimony of Sister NirmalaRaja Venkatesan

Top 8 chief business development officer resume samplesporichfergu

A V I D Juicy Ultimate Brake Bleedingradicallights

Gutell 091.imb.2004.13.495Robin Gutell

Similar to The Theory and Implementation of DVFS on Linux (20)

Meeting SEP 2.0 Compliance: Developing Power Aware Embedded Systems for the M...mentoresd

Meeting SEP 2.0 Compliance: Developing Power Aware Embedded Systems for the Modern Age – Andrew Caples The Smart Energy Profile (SEP) 2.0 is quickly becoming the go-to standard for developing innovative products and services in the energy power management sector. Information flow between meters, smart appliances, and energy management systems must occur in an open, standardized, and interoperable fashion. SEP 2.0 establishes the standard for communication interoperability as well as security for networked appliances and meters. In this session attendees will learn how to meet the challenges of SEP 2.0 compliance with a small footprint RTOS, such as Nucleus RTOS from Mentor Graphics, to address the connectivity and security requirements for the smart energy profile. This session takes a detailed look at the design considerations to consider how an RTOS can reduce development time and cost for SEP 2.0 compliant products.

Tizen Developer Conference 2017 San Francisco - Tizen Power Management Servic...Chanwoo Choi

Power Management in the key point of embedded devices because of the limited power capacity. On Tizen 4.0, PASS (Power Aware System Service) is the power management service which provides the common interface to allocate the limited resources efficiently in order to meet the performance demands and power-consumption requirements. Tizen 4.0 platform developers or vendors may tune the behaviors of PASS governor for their own devices by modifying the configuration file of PASS. It allocates the power-related resources according to the configurations, which may emphasize either power-consumption or performance (or even "balanced") and the current user context (e.g., launching a heavy app, touching or swiping the touchscreen and so on). PASS supports PM_QOS based the scenarios as well. The configuration file of PASS includes CPU, Memory Bus, GPU information and the scenario list.

DEF CON 27 - ALI ISLAM and DAN REGALADO WEAPONIZING HYPERVISORSFelipe Prado

This document discusses using hypervisors to monitor devices for cyber attacks. It begins with discussing agent-less vs agent monitoring and then demonstrates setting up a development environment using a Zynq UltraScale+ MPSoC board with Xen hypervisor. It shows building a root filesystem, getting ARM syscalls, and using virtual machine introspection to monitor syscalls and memory. Various attack scenarios are demonstrated like shellcode execution and malware awareness. It concludes with recommendations for an end-to-end monitoring system and releasing the tools developed.

Jpcmsuppport jspx

JPCM is a Java wrapper for the PCM performance monitoring tool from Intel. It provides metrics on CPU utilization, cache hits and misses, memory usage, and instruction counts. It exposes over 20 counters for the CPU cores, cache, and memory usage. Users can take snapshots before and after running code to analyze performance bottlenecks. The tool currently supports Intel Xeon and Core processors and future work includes moving to a pure Java implementation and integrating with other tools.

Introduction to National Supercomputer center in Tianjin TH-1A SupercomputerFörderverein Technische Fakultät

The document introduces the National Supercomputer Center in Tianjin (NSCC-TJ) and its TH-1A supercomputer system. It describes that NSCC-TJ is sponsored by the Chinese government to provide high performance computing services. It then provides details about the TH-1A system including its hybrid CPU and GPU architecture, proprietary interconnect network, 262TB of memory and 2PB of storage. It also summarizes the system's software stack including the Kylin Linux operating system, compilers, programming environment and visualization system.

Advanced virtualization techniques for FAUmachinewebhostingguy

This document describes advanced virtualization techniques used in FAUmachine, a virtual PC developed by researchers. It presents a just-in-time compiler that can transform kernel mode code into code suitable for execution in a user mode simulator. This allows system-level binaries and operating systems like Windows to run virtually. It also describes a small host kernel modification to simplify system call redirection, improving virtual machine performance. Details are given on the just-in-time compiler and kernel extension, and their impact on performance is evaluated.

Instruction level power analysisRadhegovind

This document discusses instruction level power analysis (ILPA) for estimating processor power consumption. It describes how ILPA works by associating an energy cost with each instruction based on its operations and accounting for inter-instruction effects. Initially used for RISC processors, ILPA methods were modified for VLIW/EPIC processors by considering independent energy dissipation across execution slots and clustering similar instructions. ILPA does not provide insight into core power consumption causes but was expanded to microarchitecture-aware models accounting for individual pipeline stages. Register files and caches can also be modeled based on access patterns and state transitions between cycles.

Flow control in computerrud_d_rcks

The document discusses different types of control flow in computer programs including sequential, selection, iteration, and recursion. It explains that in a control flow computer, instructions are executed sequentially based on the program counter. Shared memory is used to pass data between instructions by reference. Control flow computers perform computations synchronously using centralized control.

Arm7 architectureSyeda Nasiha

This document describes a hardware platform for evaluating low-energy multiprocessor embedded systems using commercial off-the-shelf devices. The platform uses two ARM7 microcontrollers that can each be powered independently and have their voltage and frequency scaled dynamically. It includes circuits to separately measure the energy and power consumption of different components. Experimental results show the delay and energy impacts of voltage scaling on various parts. The platform is intended to support research on energy management techniques for parallel processing systems.

LPAR2RRD on CZ/SK common 2014Pavel Hampl

Digital Switching System UNIT6 ROI.pptxganesh shety

Always-on Profiling of All Linux Threads, On-CPU and Off-CPU, with eBPF & Con...ScyllaDB

In this session, Tanel introduces a new open source eBPF tool for efficiently sampling both on-CPU events and off-CPU events for every thread (task) in the OS. Linux standard performance tools (like perf) allow you to easily profile on-CPU threads doing work, but if we want to include the off-CPU timing and reasons for the full picture, things get complicated. Combining eBPF task state arrays with periodic sampling for profiling allows us to get both a system-level overview of where threads spend their time, even when blocked and sleeping, and allow us to drill down into individual thread level, to understand why.

Training Distributed Deep Recurrent Neural Networks with Mixed Precision on G...Databricks

In this talk, we evaluate training of deep recurrent neural networks with half-precision floats on Pascal and Volta GPUs. We implement a distributed, data-parallel, synchronous training algorithm by integrating TensorFlow and CUDA-aware MPI to enable execution across multiple GPU nodes and making use of high-speed interconnects. We introduce a learning rate schedule facilitating neural network convergence at up to O(100) workers. Strong scaling tests performed on GPU clusters show linear runtime scaling and logarithmic communication time scaling for both single and mixed precision training modes. Performance is evaluated on a scientific dataset taken from the Joint European Torus (JET) tokamak, containing multi-modal time series of sensory measurements leading up to deleterious events called plasma disruptions. Half-precision significantly reduces memory and network bandwidth, allowing training of state-of-the-art models with over 70 million trainable parameters while achieving a comparable test set performance as single precision.

Blackfin system servicesPantech ProLabs India Pvt Ltd

The document provides an overview of the system services software available for the Blackfin family of processors. It discusses key services like the dynamic power management service, external bus interface unit (EBIU), interrupt manager, DMA manager, flag control, timer control and port control. The services provide a software library with common APIs across Blackfin processors for simplified access to functions like clock control, memory interfaces, interrupts and timers. Using these tested and modular services can help speed up development time.

New DeltaV Module Templates to Easily Configure, View, and Trend Advanced Pre...Emerson Exchange

Advanced pressure diagnostics use statistical process monitoring to characterize process variation and detect abnormal conditions such as plugged impulse lines, furnace flame instability, or distillation column flooding. New DeltaV diagnostics module templates, including control modules, operator faceplates, and process history view ease configuration and use of advanced diagnostics. Presented by Emerson's Tom Wallace and Erik Mathiason at 2011 Emerson Exchange in Nashville.

Project ACRN schedule framework introductionProject ACRN

This document discusses ACRN's CPU sharing goal and schedule framework. It aims to fully utilize physical CPU resources to support more virtual machines while keeping a small hypervisor footprint. It describes the schedule framework's roles in maintaining state machines and providing a scalable context switch architecture. The schedule framework uses a modular design with VCPU and scheduler layers. It also details the relationships between VCPUs, schedulers, physical CPUs and virtual machines. Key aspects covered include scheduling points, context switching, and ensuring FuSa/security requirements are met.

PG-Strom - A FDW module utilizing GPU deviceKohei KaiGai

PG-Strom is a module that utilizes GPUs to accelerate query processing in PostgreSQL. It uses a foreign data wrapper to push query execution to the GPU. Benchmark results show a query running 10 times faster on a table using the PG-Strom FDW compared to a regular PostgreSQL table. Future plans include supporting writable foreign tables, accelerating sort and aggregate operations using the GPU, and inheritance between regular and foreign tables. Help from the community is needed to review code, provide large real-world datasets, and understand common analytic queries.

참여기관_발표자료-국민대학교 201301 정기회의DzH QWuynh

1. The document discusses research activities related to reducing energy consumption by at least 30% through the development of core source technologies for universal operating systems. 2. It describes four papers being presented, including ones on system and device latency modeling, power management frameworks for embedded systems, and automatic selection of power policies for operating systems. 3. It also summarizes four research topics from the National University, including performance evaluation of parallel applications using a power-aware paging method on next-generation memory architectures.

Os Madsen Blockoscon2007

PowerManagementAyan Halder

This document proposes a hardware/software power management solution for an embedded system that aims to maximize power savings during idle and active system phases. It involves partitioning the system into power domains controlled by a Power Management Unit (PMU) and Power Management Integrated Circuit (PMIC). Various sleep states put domains into low power modes like CPU wait-for-interrupt to reduce leakage and dynamic power. Runtime management uses CPU frequency and voltage scaling and device idle states to lower dynamic power when load is light. Evaluation shows the approach can achieve up to 94.8% power savings in deep sleep and 10% savings from CPU frequency scaling during light loads.

Meeting SEP 2.0 Compliance: Developing Power Aware Embedded Systems for the M...mentoresd

Tizen Developer Conference 2017 San Francisco - Tizen Power Management Servic...Chanwoo Choi

DEF CON 27 - ALI ISLAM and DAN REGALADO WEAPONIZING HYPERVISORSFelipe Prado

Jpcmsuppport jspx

Introduction to National Supercomputer center in Tianjin TH-1A SupercomputerFörderverein Technische Fakultät

Advanced virtualization techniques for FAUmachinewebhostingguy

Instruction level power analysisRadhegovind

Flow control in computerrud_d_rcks

Arm7 architectureSyeda Nasiha

LPAR2RRD on CZ/SK common 2014Pavel Hampl

Digital Switching System UNIT6 ROI.pptxganesh shety

Always-on Profiling of All Linux Threads, On-CPU and Off-CPU, with eBPF & Con...ScyllaDB

Training Distributed Deep Recurrent Neural Networks with Mixed Precision on G...Databricks

Blackfin system servicesPantech ProLabs India Pvt Ltd

New DeltaV Module Templates to Easily Configure, View, and Trend Advanced Pre...Emerson Exchange

Project ACRN schedule framework introductionProject ACRN

PG-Strom - A FDW module utilizing GPU deviceKohei KaiGai

참여기관_발표자료-국민대학교 201301 정기회의DzH QWuynh

Os Madsen Blockoscon2007

PowerManagementAyan Halder

More from Picker Weng (8)

Introduction to Agile & ScrumPicker Weng

Android Multimedia FrameworkPicker Weng

This document discusses the Android multimedia framework on Jelly Bean. It provides an introduction to OpenMAX and describes the simple stack architecture including the developer API, event handler, surface holder, StageFright, OpenMAX interface, and software/hardware codecs. It explains the workflows and sequence flows for playing a media file, including setting the data source, preparing to play, and starting playback. Finally, it covers the synchronization architecture and flow of StageFright.

Tutorial for Installing ecloxPicker Weng

Chromium OS - User Accounts and ManagementPicker Weng

The Chromium OS device includes many configurations such as network, whitelist, bookmark, themes, and etc. We can simply distinguish these settings between system settings and user preference. In general, every user would like to have own configuration. This means user can define their theme, network configuration, and etc. But user’s data is always stored in the cloud server in the cloud-based device so that we have to sync these data down to device from web. For this reason, the Chromium OS device should know that which user is logging in to device, and then sync his data down to. Therefore, Google’s Chromium OS team develops some mechanism to manage user accounts and settings.

[C++ GUI Programming with Qt4] chap6Picker Weng

Ch 6 Layout Management discusses various Qt layout managers for organizing widgets in a user interface. Absolute positioning can cause issues with resizing and translating, so layout managers like QGridLayout automatically adjust widget positions and sizes. QSizePolicy properties define how widgets behave when the parent widget is resized. QStackedLayout and QSplitter allow multiple widgets to be viewed or resized simultaneously within the available space. Scrolling areas, dock windows, tool bars, and MDI interfaces provide more complex layout capabilities for application windows.

OpenCV 2.2.0 for AndroidPicker Weng

UmlPicker Weng

Vim+cscope+ctags+taglistPicker Weng

This document discusses how to make the vim text editor more powerful for programmers by adding cscope, ctags, and taglist plugins. These plugins allow vim to provide features like finding definitions, viewing call hierarchies, and browsing function lists that are typically found in integrated development environments. It provides instructions for installing these plugins and summaries of how they enhance vim's capabilities.

Introduction to Agile & ScrumPicker Weng

Android Multimedia FrameworkPicker Weng

Tutorial for Installing ecloxPicker Weng

Chromium OS - User Accounts and ManagementPicker Weng

[C++ GUI Programming with Qt4] chap6Picker Weng

OpenCV 2.2.0 for AndroidPicker Weng

UmlPicker Weng

Vim+cscope+ctags+taglistPicker Weng

Recently uploaded (20)

Computer Systems Quiz Presentation in Purple Bold Style (4).pdffizarcse

Build With AI - In Person Session Slides.pdfGoogle Developer Group - Harare

Build with AI events are communityled, handson activities hosted by Google Developer Groups and Google Developer Groups on Campus across the world from February 1 to July 31 2025. These events aim to help developers acquire and apply Generative AI skills to build and integrate applications using the latest Google AI technologies, including AI Studio, the Gemini and Gemma family of models, and Vertex AI. This particular event series includes Thematic Hands on Workshop: Guided learning on specific AI tools or topics as well as a prequel to the Hackathon to foster innovation using Google AI tools.

Developing Product-Behavior Fit: UX Research in Product Development by Krysta...UXPA Boston

What if product-market fit isn't enough? We’ve all encountered companies willing to spend time and resources on product-market fit, since any solution needs to solve a problem for people able and willing to pay to solve that problem, but assuming that user experience can be “added” later. Similarly, value proposition-what a solution does and why it’s better than what’s already there-has a valued place in product development, but it assumes that the product will automatically be something that people can use successfully, or that an MVP can be transformed into something that people can be successful with after the fact. This can require expensive rework, and sometimes stops product development entirely; again, UX professionals are deeply familiar with this problem. Solutions with solid product-behavior fit, on the other hand, ask people to do tasks that they are willing and equipped to do successfully, from purchasing to using to supervising. Framing research as developing product-behavior fit implicitly positions it as overlapping with product-market fit development and supports articulating the cost of neglecting, and ROI on supporting, user experience. In this talk, I’ll introduce product-behavior fit as a concept and a process and walk through the steps of improving product-behavior fit, how it integrates with product-market fit development, and how they can be modified for products at different stages in development, as well as how this framing can articulate the ROI of developing user experience in a product development context.

Cybersecurity Threat Vectors and MitigationVICTOR MAESTRE RAMIREZ

Understanding SEO in the Age of AI.pdfFulcrum Concepts, LLC

Secondary Storage for a microcontroller systemfizarcse

Agentic Automation - Delhi UiPath Community MeetupManoj Batra (1600 + Connections)

Original presentation of Delhi Community Meetup with the following topics ▶️ Session 1: Introduction to UiPath Agents - What are Agents in UiPath? - Components of Agents - Overview of the UiPath Agent Builder. - Common use cases for Agentic automation. ▶️ Session 2: Building Your First UiPath Agent - A quick walkthrough of Agent Builder, Agentic Orchestration, - - AI Trust Layer, Context Grounding - Step-by-step demonstration of building your first Agent ▶️ Session 3: Healing Agents - Deep dive - What are Healing Agents? - How Healing Agents can improve automation stability by automatically detecting and fixing runtime issues - How Healing Agents help reduce downtime, prevent failures, and ensure continuous execution of workflows

React Native for Business Solutions: Building Scalable Apps for SuccessAmelia Swank

Mastering Testing in the Modern F&B Landscapemarketing943205

Dive into our presentation to explore the unique software testing challenges the Food and Beverage sector faces today. We’ll walk you through essential best practices for quality assurance and show you exactly how Qyrus, with our intelligent testing platform and innovative AlVerse, provides tailored solutions to help your F&B business master these challenges. Discover how you can ensure quality and innovate with confidence in this exciting digital era.

Design pattern talk by Kaya Weers - 2025 (v2)Kaya Weers

Who's choice? Making decisions with and about Artificial Intelligence, Keele ...Alan Dix

Invited talk at Designing for People: AI and the Benefits of Human-Centred Digital Products, Digital & AI Revolution week, Keele University, 14th May 2025 https://www.alandix.com/academic/talks/Keele-2025/ In many areas it already seems that AI is in charge, from choosing drivers for a ride, to choosing targets for rocket attacks. None are without a level of human oversight: in some cases the overarching rules are set by humans, in others humans rubber-stamp opaque outcomes of unfathomable systems. Can we design ways for humans and AI to work together that retain essential human autonomy and responsibility, whilst also allowing AI to work to its full potential? These choices are critical as AI is increasingly part of life or death decisions, from diagnosis in healthcare ro autonomous vehicles on highways, furthermore issues of bias and privacy challenge the fairness of society overall and personal sovereignty of our own data. This talk will build on long-term work on AI & HCI and more recent work funded by EU TANGO and SoBigData++ projects. It will discuss some of the ways HCI can help create situations where humans can work effectively alongside AI, and also where AI might help designers create more effective HCI.

DNF 2.0 Implementations Challenges in NepalICT Frame Magazine Pvt. Ltd.

May Patch TuesdayIvanti

Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.

Harmonizing Multi-Agent Intelligence | Open Data Science Conference | Gary Ar...Gary Arora

This deck from my talk at the Open Data Science Conference explores how multi-agent AI systems can be used to solve practical, everyday problems — and how those same patterns scale to enterprise-grade workflows. I cover the evolution of AI agents, when (and when not) to use multi-agent architectures, and how to design, orchestrate, and operationalize agentic systems for real impact. The presentation includes two live demos: one that books flights by checking my calendar, and another showcasing a tiny local visual language model for efficient multimodal tasks. Key themes include: ✅ When to use single-agent vs. multi-agent setups ✅ How to define agent roles, memory, and coordination ✅ Using small/local models for performance and cost control ✅ Building scalable, reusable agent architectures ✅ Why personal use cases are the best way to learn before deploying to the enterprise

In-App Guidance_ Save Enterprises Millions in Training & IT Costs.pptxaptyai

Right to liberty and security of a person.pdfdanielbraico197

Google DeepMind’s New AI Coding Agent AlphaEvolve.pdfderrickjswork

In a landmark announcement, Google DeepMind has launched AlphaEvolve, a next-generation autonomous AI coding agent that pushes the boundaries of what artificial intelligence can achieve in software development. Drawing upon its legacy of AI breakthroughs like AlphaGo, AlphaFold and AlphaZero, DeepMind has introduced a system designed to revolutionize the entire programming lifecycle from code creation and debugging to performance optimization and deployment.

OpenAI Just Announced Codex: A cloud engineering agent that excels in handlin...SOFTTECHHUB

How Top Companies Benefit from OutsourcingNascenture

ICDCC 2025: Securing Agentic AI - Eryk Budi Pratama.pdfEryk Budi Pratama

Title: Securing Agentic AI: Infrastructure Strategies for the Brains Behind the Bots As AI systems evolve toward greater autonomy, the emergence of Agentic AI—AI that can reason, plan, recall, and interact with external tools—presents both transformative potential and critical security risks. This presentation explores: > What Agentic AI is and how it operates (perceives → reasons → acts) > Real-world enterprise use cases: enterprise co-pilots, DevOps automation, multi-agent orchestration, and decision-making support > Key risks based on the OWASP Agentic AI Threat Model, including memory poisoning, tool misuse, privilege compromise, cascading hallucinations, and rogue agents > Infrastructure challenges unique to Agentic AI: unbounded tool access, AI identity spoofing, untraceable decision logic, persistent memory surfaces, and human-in-the-loop fatigue > Reference architectures for single-agent and multi-agent systems > Mitigation strategies aligned with the OWASP Agentic AI Security Playbooks, covering: reasoning traceability, memory protection, secure tool execution, RBAC, HITL protection, and multi-agent trust enforcement > Future-proofing infrastructure with observability, agent isolation, Zero Trust, and agent-specific threat modeling in the SDLC > Call to action: enforce memory hygiene, integrate red teaming, apply Zero Trust principles, and proactively govern AI behavior Presented at the Indonesia Cloud & Datacenter Convention (IDCDC) 2025, this session offers actionable guidance for building secure and trustworthy infrastructure to support the next generation of autonomous, tool-using AI agents.

Computer Systems Quiz Presentation in Purple Bold Style (4).pdffizarcse

Build With AI - In Person Session Slides.pdfGoogle Developer Group - Harare

Developing Product-Behavior Fit: UX Research in Product Development by Krysta...UXPA Boston

Cybersecurity Threat Vectors and MitigationVICTOR MAESTRE RAMIREZ

Understanding SEO in the Age of AI.pdfFulcrum Concepts, LLC

Secondary Storage for a microcontroller systemfizarcse

Agentic Automation - Delhi UiPath Community MeetupManoj Batra (1600 + Connections)

React Native for Business Solutions: Building Scalable Apps for SuccessAmelia Swank

Mastering Testing in the Modern F&B Landscapemarketing943205

Design pattern talk by Kaya Weers - 2025 (v2)Kaya Weers

Who's choice? Making decisions with and about Artificial Intelligence, Keele ...Alan Dix

DNF 2.0 Implementations Challenges in NepalICT Frame Magazine Pvt. Ltd.

May Patch TuesdayIvanti

Harmonizing Multi-Agent Intelligence | Open Data Science Conference | Gary Ar...Gary Arora

In-App Guidance_ Save Enterprises Millions in Training & IT Costs.pptxaptyai

Right to liberty and security of a person.pdfdanielbraico197

Google DeepMind’s New AI Coding Agent AlphaEvolve.pdfderrickjswork

OpenAI Just Announced Codex: A cloud engineering agent that excels in handlin...SOFTTECHHUB

How Top Companies Benefit from OutsourcingNascenture

ICDCC 2025: Securing Agentic AI - Eryk Budi Pratama.pdfEryk Budi Pratama

The Theory and Implementation of DVFS on Linux

1. The Theory and Implementation of DVFS on Linux

6. Offline Optimization Static Power Management (SPM) Dynamic Power Management (DPM) Online Optimization

7. Static Power Management (SPM) System/Component Level of Detail Evaluation Under Test RTL level Cycle-level simulation CPU Instruction level Instruction-level simulation Hardware component level Functional simulation System Software component level Monitoring tool Hardware & Software Complete system simulation component level

8. Dynamic Power Management (DPM) System/Component Under Test (SUT/CUT) Implementation Level Methodology DVS (Dynamic Voltage CPU CPU and System software Scaling) Low power mode of System Components hardware operation CVS (Coordinated Voltage Cluster System CPU and System software Scaling)

9. IDEA?

14. Dynamic Power of CMOS Circuits Core Voltage P ∝ fV 2 Clock Frequency

15. Dynamic Voltage and Frequency Scaling (DVFS)

16. 思考實際的使用……

17. Routine in User Space

18. Workflow of the Power Estimation Models

19. Framework of the Predictive User-Aware Power Management

20. Linux Kernel 支援了基本的架構

21. Linux 電源管理架構

22. Kernel Module Governor Functionality cpufreq_ondemand ondemand 按需求調節，不是很強大，但實現了動態頻率調節 cpufreq_powersave powersave 省電模式，通常以最低頻率運行， cpufreq_userspace userspace 用戶模式，一些調頻工具軟件需要在此模式下才能運行 cpufreq_conservative conservative “ 保守”模式，類似於 ondemand ，但調整相對較緩 N/A performance 不降頻

23. Implementation on Intel XScale-PXA270

24. Performance Monitoring Unit

27. CPUFreq Definition

29. User-Space Application

30. Open Source ● https://github.com/pickerweng/syf-pwm

The Theory and Implementation of DVFS on Linux

Recommended

More Related Content

What's hot (20)

Viewers also liked (20)

Similar to The Theory and Implementation of DVFS on Linux (20)

More from Picker Weng (8)

Recently uploaded (20)

The Theory and Implementation of DVFS on Linux