Sefos A self-aware factored operating system A Traditional OS App 1 - - PowerPoint PPT Presentation

Sefos A self-aware factored operating system

2

A Traditional OS

Operating System

Disk I/O Devices DRAM

App 2 App 1 App 3

Memory Manager File System Device Drivers Scheduler

App 1

Core

Cache

App 2 App 3

Core

Cache

System call

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Sefos: A Self-Aware OS

sefos: A Self-Aware Operating System

Disk I/O Devices DRAM

App 2 App 1 App 3

miss rate voltage, freq, precision cache size, associativity power

Memory Manager File System Device Drivers Scheduler

activity, power, temp

App 1

Analysis & Optimization Engine Observe Decide Act Core

Cache

App 2 App 3

Learner

Core

Cache

System call

speed algorithm heartbeat, goals

Heartbeat/ Performance measurements

Control system

PEP Core

Cache

PEP Core

Cache

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Sefos is Factored

I/O !"# #!"# #!"# !"# #!"# #!"# !"# User App !"# !"# $%%&# '%(# )*+%# !,-%# .%*&#

! $"#%&'()*+,#-.()#/+*0-'+/#1+232#.&4+#/+*0-'+5#6&3+#/+*0-'+#!"5#78+#/+*0-'+#9":# ! ;&'<#/+*0-'+#-/#%=*(<+*#%&'()*+,#-.()#&#!""#$)%#,-/(*->=(+,#/+*0+*/## ! ;&'<#/+*0+*#-/#>)=.,#()#&#')*+# ! ?668-'&@).#')*+/#4+//&3+#&#6&*@'=8&*#/+*0+*#')*+#()#=@8-A+#/+*0-'+# ! "+*0+*#')*+/#')88&>)*&(+B')44=.-'&(+#()#-468+4+.(#.++,+,#$"#/+*0-'+#

Core

File system fleet

! Sefos Analysis and

Optimization Engine

! A closed feedback loop of

ODA

! Each component provides a

new OS service:

! The observer provides vital

signs services

! The decision engine provides

performance models and AI learning engine

! The actuators modifies system

status ! Each component is either

implemented as a fos fleet

• r integrated into another

S/W components.

5 Analysis & Optimization Engine

Vital Signs

(e.g. heartbeats)

Observe

Decision Engine

• performance models
• control system
• learner

Decide

Actuators

Act

Sefos is Self-Aware

Analysis & Optimization Engine

• Applications (e.g. algorithms)
• OS sub-systems (e.g.

growing fleets)

• Hardware components (e.g.

frequency scaling)

Vital Signs Fleet

! Observes the status of software

and hardware components.

! Provides a distributed, global

knowledge-base of the system

! Implemented as a fleet, storing

the information in a distributed data object

!

key-value store

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Vital Signs

(e.g. heartbeats)

Observe

Decision Engine Actuators

Sefos: Building self-awareness into fos

Analysis & Optimization Engine ! Collects measurements from:

1) Applications e.g. Apps heartbeats, Application-specific measurements (fps in a video encoder or flops in a scientific app) 2) OS subsystems e.g. Utilization ratio of the file system fleet 3) Hardware components e.g. temperature, core frequency, power, cache miss rate

Decision Engine

! A new OS service ! Implemented through a fleet of

servers for scalability

! Process input from the vital

signs service

! Provides two approaches to

runtime decision making:

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Vital Signs Decision Engine

(e.g. performance models, control system, AI learner)

Decide

Actuators

Sefos: Building self-awareness into fos

Analysis & Optimization Engine

" Machine learning " Classical control theory

Actuators

! Actions allowing the system to

adapt at runtime

! Three sets of actions, based on

their impact:

• Application actions
• Allocating or de-allocating cores to

an application

• Switching between algorithms
• Migrating processes for better data

locality and cache usage

• OS services actions
• Growing and shrinking fleets
• Migrating servers
• Hardware actions
• Frequency scaling to save power

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Vital Signs Decision Engine Actuators

Act

Sefos: Building self-awareness into fos

Analysis & Optimization Engine

• Applications
• OS sub-systems
• Hardware components (e.g.

frequency scaling)

" Implemented as extension to fos fleets, OS tools for hardware actions or

application-specific actions

9 9

Observe-Decide-Act Loop in Sefos

App OS Runtime Compiler Arch – net Arch – mem Arch – proc Logic & circuits Device

O D A Heartbeats Algorithm Choice D O A Dynamic voltage scaling O D A Heartbeats frequency scaling O A D Computation Migration