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{{admon/note|Live Image Friendly|You may run this test case using the USB or CD live image if you install the powertop utility with <code>yum install powertop</code>}}
{{admon/note|Live Image Friendly|You may run this test case using the USB or CD live image if you install the powertop utility with <code>yum install powertop</code>}}
{{admon/Caution|Hotplug issues|SATA link power states other than max_performance may cause problems with hotplugable external SATA ports and devices attached to those ports may have problems. Internal devices should be unaffected.}}
{{admon/caution|Hotplug issues|SATA link power states other than max_performance may cause problems with hotplugable external SATA ports and devices attached to those ports may have problems. Internal devices should be unaffected.}}
{{admon/important|System must remain idle|Please do not do any other work on the system while running this test, otherwise power usage figures may be inaccurate.}}  
{{admon/important|System must remain idle|Please do not do any other work on the system while running this test, otherwise power usage figures may be inaccurate.}}  
# Make sure laptop battery is fully charged.
# Make sure laptop battery is fully charged.

Revision as of 19:21, 21 October 2009

Description

A simple test to determine effect of SATA link power management settings on power consumption.
Privileges: Root
Runlevel: singleuser
ETA: 10 minutes


How to test

Note.png
Live Image Friendly
You may run this test case using the USB or CD live image if you install the powertop utility with yum install powertop
Stop (medium size).png
Hotplug issues
SATA link power states other than max_performance may cause problems with hotplugable external SATA ports and devices attached to those ports may have problems. Internal devices should be unaffected.
Important.png
System must remain idle
Please do not do any other work on the system while running this test, otherwise power usage figures may be inaccurate.
  1. Make sure laptop battery is fully charged.
  2. Reboot laptop to single user mode.
  3. Unplug AC power from the laptop.
  4. run: for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo max_performance > $i; done
  5. run: powertop -d -t 60 | grep 'Power usage'
  6. Record the power usage estimate printed in Watts. This will be the power consumption at the max_performance setting.
  7. run: for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo medium_power > $i; done
  8. run: powertop -d -t 60 | grep 'Power usage'
  9. Record the power usage estimate printed in Watts. This will be the power consumption at the medium_power setting.
  10. run: for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo min_power > $i; done
  11. run: powertop -d -t 60 | grep 'Power usage'
  12. Record the power usage estimate printed in Watts. This will be the power consumption at the min_power setting.

Expected Results

Please add the following to the results table.

  1. Power consumption for all three link power settings, max_performance, medium_power, min_power.
  2. Your smolt system profile. (no need to resubmit if you have already for one of the other tests)
  3. Please open bugs if you notice any abnormal behavior such as system hangs, kernel oops messages, serious IO performance degradation.
  4. You may return your system to its default state by running the command in step 4 again or just reboot.