[PPT] - Prioritized Access Arbitration to Shared Resources on Integrated PowerPoint Presentation

SLIDE 1

Prioritized Access Arbitration to Shared Resources

n Integrated Software Systems

in Multicore Environments

14th December 2012, Liverpool Andreas Knirsch, Pierre Schnarz, Joachim Wietzke

SLIDE 2

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

In-Car Multimedia Systems

standard equipment
heterogeneous functionalities
influences from Consumer Electronics (CE)

2

I C M

SLIDE 3

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

ICM provides bridge to "outside world"

3

ECU=Electronic Control Unit

infrastructure provide sensors and actuators

fieldbus

ICM Head Unit 3G LTE ECU ECU ECU

SLIDE 4

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Automotive Environment

4

harsh environment long lifetime challenging maintenance reliability

SLIDE 5

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Parallel Development

division of labour follows system's

breakdown structure

many parties involved with different domain

knowledge/background 9 companies 13 locations 235 developers

> 20M loc
> 45 variants

5

SLIDE 6

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Heterogeneous Applications

Entertain fm-tuner streaming media internet Control air- condition seat position door lock Assist navigation rear/side view camera breakdown help HMI displays voice recognition input devices

... ... ... ...

6

>500 parallel/async. tasks 2-5 displays multi-user system

SLIDE 7

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

From Federated Systems to Integrated Execution Domains (ED)

7

navi. phone ... media

fieldbus

SLIDE 8

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

From Federated Systems to Integrated Execution Domains (ED)

7

navi. phone ... media

i n f r a s t r u c t u r e Execution Domains

fieldbus

prioritized and preemptive scheduling domains

SLIDE 9

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

iPod SD-Flash USB-Flash Storage Displays Touch Knobs Speech Operation CAN MOST GPS Fieldbus and Sensors GSM 3G/LTE WIFI BT Connectivity

Navigation Media Player User Interface Browser Phone ... Tuner Infrastructure Application Operating System Software-Framework

I/O Resources

8

SLIDE 10

software hardware

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Issue: Unprioritized Access to Resources

Operating System ED ED ED core 1 core 2 core n res. res. res.

prioritize tasks different importance compute parallel

... ...

unprioritized access

non-deterministic temporal behavior

9

affects behavior of the overall system

unprioritized access

res. res. res.

SLIDE 11

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs

h_da

Hochschule Darmstadt University of Applied Sciences

Prioritized Access Arbitration to Shared Resources

3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Motivation SHARB Summary

Shared Resource Arbiter (SHARB)

to achieve a more deterministic temporal behavior

10

when accessing shared resources that do not support parallel usage to improve composability

SLIDE 12

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Requirements

predictable latency for access
no modification of applications is necessary
access can be ordered using static priorities
portable to different software platforms
appear transparent to application programmer
configurable to be used only for selected resources

11

SLIDE 13

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Scope of SHARB

multicore hardware platforms
operating system with priority based SMP scheduler
component based application
components with different temporal requirements
resources that require exclusive access

Execution Domains (ED)

12

SLIDE 14

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Architectural Layers of SHARB

Device Manager Service Driver Device Instance Application SHARB Resource Application Context User Space

13

allow resource specific implementation determines priority assign effective priority redirect POSIX calls

SLIDE 15

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Dependencies (Exemplary Scenario)

Device Manager SD 1.A Device Instance A ED 1 Resource A ED 2 ED 3 SD 2.A SD 2.B SD 3.B Resource B Device Instance B SHARB

14

SLIDE 16

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Integration into a Automotive Software Framework

utilize existing ED abstraction
provides relation of task to ED to identify accessor
enables integrator to define static access priorities

along with the task priorities

OpenICM

Device Manager Service Driver Device Instance Application SHARB Resource Application Context User Space

15

QNX RTOS GNU/LINUX

SLIDE 17

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Experiments

Prioritization:

multiple reader access a resource concurrently => high priority access finishes first, independent of task priorities and CPU affinity

Temporal Overhead:

compare non-arbitrated and arbitrated access (variations in amount and repetitions) => overhead decrease with increasing repetitions => amount of transmitted data is not significant

16

ED 1 Res. ED 2 ED 1 Res. SHARB

Δt

SLIDE 18

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

17

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

50 100 150 200 250 0.00233 0.00235 0.00237 0.00239 read data (bytes) mean duration (sec)

max. overhead = 2.365 msec
min. overhead = 2.354 msec

distribution = 0.011 msec

(a) Absolute overhead in relation to size.

! ! ! ! ! ! !

5 10 15 20 25 30 0.002350 0.002360 0.002370 number of reads mean duration (sec)

max. overhead = 2.361 msec
min. overhead = 2.359 msec

distribution = 0.002 msec

(b) Absolute overhead in relation to repetitions.

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

50 100 150 200 250 0.00145 0.00155 0.00165 0.00175 read data (bytes) mean duration (sec)

max. overhead = 1.737 msec
min. overhead = 1.471 msec

distribution = 0.266 msec

! ! ! ! ! ! !

5 10 15 20 25 30 0.00158 0.00160 0.00162 number of reads mean duration (sec)

max. overhead = 1.618 msec
min. overhead = 1.583 msec

distribution = 0.036 msec

LINUX: QNX: more absolute overhead, less variance

SLIDE 19

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Conclusions

introduction of multicore hardware

enables parallel execution

arbitration of resource access is necessary to

achieve predictable temporal behavior

SHARB provides a portable solution with

deterministic overhead for a subset of I/O resources

18

SLIDE 20

Motivation SHARB Summary

IN-CAR MULTIMEDIA LABS, Andreas Knirsch

Prioritized Access Arbitration to Shared Resources

h_da

Hochschule Darmstadt University of Applied Sciences

fbi

Fachbereich Informatik Faculty of Computer Science

icm

In-Car Multimedia Labs 3rd IEEE International Conference on Networked Embedded Systems for Every Application (NESEA 2012)

Further Directions

concepts are portable to other system architectures

(e.g. virtualization, asynchronous multiprocessing)

complementary concepts for audio/video

are further research questions

19

SLIDE 21

Prioritized Access Arbitration to Shared Resources

n Integrated Software Systems