Suspended time vs Resumed time in an idle XO

Giannis Galanis galanis at laptop.org
Fri Feb 22 14:55:48 EST 2008


I have noticed that an idle machine will resume for some time, and suspend
again, several times for no reason.

I wrote a simple script that checks every 1sec whether the machine is
suspended on not.
It gives a timeline of Suspended times and Resumed times.


A left an XO completely idle overnight for 12h.

The results were:

It resumed about 80 times
It was resuming every 1m to 10min
The total suspended time percentage was 90%

Do these numbers seem normal?

Chris was mentioning the other day about the additional power consumed to
resume the XO.
I can assume that resuming/suspending at a regular basis is not very power
efficient.


Also, this script made it easy to examine what happens to timeouts that are
interrupted with suspends.

The result is that the suspended time extends the timeout. The timeout does
not expire relative to the absolute time, but the time the CPU is alive.
So if a 10min timeout is interrupted by a 2min suspend, the timeout will
expire 12min after the point it was executed.
Scott, does this agree with what you expected?
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