[LUCID] [PATCH] PM: Measure device suspend and resume times

Andy Whitcroft apw at canonical.com
Mon Jan 25 13:35:31 UTC 2010


On Sun, Jan 24, 2010 at 07:05:53PM -0600, Manoj Iyer wrote:
> 
> The following patch from Rafael measures the suspend/resume times of 
> devices. It logs the total suspend/resume times of devices as follows:
> 
> [   62.820296] PM: suspend of devices complete after 2108.836 msecs
> [   62.820300] PM: suspend devices took 2.110 seconds
> [   62.860107] PM: late suspend of devices complete after 39.801 msecs
> [   63.440105] PM: early resume of devices complete after 20.013 msecs
> [   67.337821] PM: resume of devices complete after 3887.665 msecs
> [   67.338078] PM: resume devices took 3.890 seconds
> [   67.338117] PM: Finishing wakeup.

How does this help us above and beyond the counts we already have?  In
karmic and lucid we already get these:

[55841.240147] PM: suspend devices took 1.500 seconds
[55845.696481] PM: resume devices took 3.850 seconds

It looks to my eye all I am getting from this patch is the late suspend
and early resume numbers?  Are these useful enough to warrent patching?
What do they represent?

Convince me :)

-apw




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