Power Management 'res publica' EXERCISE - STEP 1 INTRO: I'm here today to talk to you about the value of having a relationship with Red Hat. [ Whiteboard Exercise ] Before we get started, I want to capture a few thoughts you may have about what Red Hat is today. Possibly some of the following words: [ Write examples in a single column as you say them ] Linux Open source Jboss Low-cost Performance Freedom This is all true, and it's part of what of we offer, but but what we want to talk to you about today is something more compelling that Red Hat has to offer from a value and relationship perspective. Jiří Skála Base-OS Brno (CZ), Power management team

Why and what to save? Select what you want ... Energy Battery life - longer mobility Money - less energy affects your bank account Ecology – sparing environment Increase performance – optimized processes can increase performance

Dr. Eater & Mr. Appetite? Hardware is real power eater Two states only - on/off Software controls appetite to eat Firmware controls periphery (HDD e.g. WD RE2-GP IntelliPower) Functionality Performance Power consumption OS components affects power consumption directly Applications affect power consumption mostly indirectly via OS

Measurement & monitoring bltk – The Battery Life Tool Kit simulates reproducible load (office work, reading, video playing, user defined) measures battery discharging, charging, battery life etc. tuned – monitoring and tuning daemon monitors system usage and dynamically tunes it (currently LAN and HDD) tuned-adm is administrating tool to set up predefined profile scomes – measurement of CPU usage and i/o operations powertop – measurement of wake-ups Measurement Test day Automated measurement

Diet Design On/off - turn off what isn't needed hardware level You don't need always gigabit LAN Usage more effective power supply (active PFC) software level (good design on the start of project) On/off - turn off what isn't needed Lower-slower - switch hardware to lower energy state CPU governor Wifi saving mode (AP support), LAN 1GB/s -> 100 MB/s (switch support) HDD spin down (HDD life goes down) Optimization – applications contain power eater(s)

How many [W] consumes components HW table - https://fedoraproject.org/wiki/SIGs/PowerManagement

Why res publica? Easy tuning - little amount to save Turn off unused hardware and services Switch hardware to lower energy state if possible Is there real profit? (HDD active/pm idle 1 W/0.8 W, stand-by 0.25 W, starting 5.5 W) Optimization - large potential to save Minimize wake-ups Minimize i/o operations Turn off when idle (GPU, output, etc.) All developers are involved – PM is 'res publica'!

“Effective programming techniques – Less Watts/Power Management” To be continued ... “Effective programming techniques – Less Watts/Power Management” Questions, Remarks