[itistoday]

Hi, I'm not sure if I'm seeing the kernel idle at what it should, this leads me to believe that there might be some renegade kernel extension that is misbehaving. However, before I embark on the painful journey of disabling kernel extensions one-by-one I'd like to make sure that what I'm seeing is anomalous.

If you own a fully-upgraded (as of this post it's 10.5.2) Macbook or Macbook Pro, with all the latest security updates and firmware updates, I would appreciate it if you helped with this little experiment, it might help you discover whether you have renegade extensions as well, and this can lead to poor performance and a shorter battery life.

1) Open up the Terminal in /Applications/Utilities/Terminal
2) Close all other applications. You need to make sure your computer is "idle".
3) Enter this into the terminal (it's a single line) and press enter:

code:

top -ocpu -R -F -s 2 -n30 -l 6 | grep kernel

4) Wait until it stops outputting, there should be 5 lines that each look something like this:

code:

0 kernel_tas 2.8% 5:21.66 60 2 0 0- 0 71M 1793M

5) You're interested in the second number, the one with the % next to it.

Take these 5 numbers and average them (add them up and divide by 5) and post your results here. From what I could tell I'm getting somewhere around 2.6% on average.

Thanks!!

Edit: Also, it would help if you posted what kind of notebook you're running this on! (cpu frequency, etc) (I'm running a Macbook Pro 2.2 Ghz C2D)

[davidflas]

These are the results from the Macbook in my sig running 10.5.2, all updates installed:

0 kernel_tas 1.1% 7:53.37 56 2 0 0- 0 138M 1828M
0 kernel_tas 1.0% 7:53.39 56 2 0 0 0 138M 1828M
0 kernel_tas 1.1% 7:53.42 56 2 0 0 0 138M 1828M
0 kernel_tas 1.0% 7:53.44 56 2 0 0 0 138M 1828M
0 kernel_tas 1.0% 7:53.46 56 2 0 0 0 138M 1828M

Average: 1.04

[richwig83]

macbook pro 15" 2.4Ghz 2gb 200gb

Im averaging 2.1%

[Chuckit]

Keep in mind that running top to observe the kernel's CPU usage might change the kernel's CPU usage.

[pat++]

MacBook Pro 15" 2.2ghz, 2gb, 120gb:

0 kernel_tas 1.8% 12:46.32 57 2 0 0- 0 154M 1184M
0 kernel_tas 1.7% 12:46.35 57 2 0 0 0 154M 1184M
0 kernel_tas 1.6% 12:46.39 57 2 0 0 0 154M 1184M
0 kernel_tas 1.7% 12:46.42 57 2 0 0 0 154M 1184M
0 kernel_tas 1.7% 12:46.46 57 2 0 0 0 154M 1184M

Average: 1.7

[itistoday]

Originally Posted by Chuckit 

Keep in mind that running top to observe the kernel's CPU usage might change the kernel's CPU usage.

Oh sure, but this does not matter if the test requires that everyone run the same top command. This is a very rough test.

I forgot to mention, please post your system specs. Thanks! (And so far it does seem that my average is out of the ordinary.. but it seems to be fluctuating, at one point it was very high and I could barely move the mouse cursor using the trackpad, and typing was very slow, but whatever it was seems to have disappeared)

[Tomchu]

I didn't heed your request to shut down my running programs. :-P

0 kernel_tas 0.9% 14:14.74 53 2 0 0- 0 164M 1217M
0 kernel_tas 0.9% 14:14.76 53 2 0 0 0 164M 1217M
0 kernel_tas 1.0% 14:14.78 53 2 0 0 0 164M 1216M
0 kernel_tas 0.9% 14:14.80 53 2 0 0 0 165M 1217M
0 kernel_tas 1.2% 14:14.83 53 2 0 0 0 164M 1217M

MacBook Air, 1.6 GHz

[spiff72]

Airport turned off:

0 kernel_tas 1.8% 0:08.64 60 2 0 0- 0 90M 1209M
0 kernel_tas 1.8% 0:08.67 60 2 0 0 0 90M 1209M
0 kernel_tas 1.7% 0:08.71 60 2 0 0 0 90M 1209M
0 kernel_tas 1.8% 0:08.75 60 2 0 0 0 90M 1209M
0 kernel_tas 1.9% 0:08.79 60 2 0 0 0 90M 1209M

Airport turned on:

0 kernel_tas 2.9% 0:12.49 60 2 0 0- 0 90M 1209M
0 kernel_tas 3.0% 0:12.55 60 2 0 0 0 90M 1209M
0 kernel_tas 2.8% 0:12.61 60 2 0 0 0 90M 1209M
0 kernel_tas 2.8% 0:12.66 60 2 0 0 0 90M 1209M
0 kernel_tas 2.5% 0:12.72 60 2 0 0 0 90M 1209M

2.5GHz 17" MBP HR Glossy with 2GB (soon to be 4GB). Measurements taken within about 4 minutes of a restart.

[hookem2oo7]

0 kernel_tas 3.2% 6:12.06 63 2 0 0- 0 207M 1784M
0 kernel_tas 1.7% 6:12.09 63 2 0 0 0 207M 1784M
0 kernel_tas 1.6% 6:12.12 63 2 0 0 0 207M 1784M
0 kernel_tas 1.8% 6:12.16 63 2 0 0 0 207M 1784M
0 kernel_tas 1.8% 6:12.20 63 2 0 0 0 206M 1784M

2.2MBP, 120GB, 4GB, Airport on, Safai and Mail open

[itistoday]

Thanks everyone for your results! I think the values I'm seeing right now are within they normal range. They're now around 1.7%, I don't know what that weird behavior I experienced earlier was, but whatever it was it seems to be gone now thankfully. Thanks again!

[harbinger75]

0 kernel_tas 1.4% 3:12.60 56 2 0 0- 0 58M 1209M
0 kernel_tas 1.3% 3:12.63 56 2 0 0 0 58M 1209M
0 kernel_tas 1.3% 3:12.66 56 2 0 0 0 58M 1209M
0 kernel_tas 1.4% 3:12.69 56 2 0 0 0 58M 1209M
0 kernel_tas 1.6% 3:12.72 56 2 0 0 0 58M 1209M

1.4% was the average.

2.2Ghz MacBook, Late 2007, 2GB RAM

[initou]

Config: MacBook Air 1.6 GHz... What the hell ?
0 kernel_tas 66.1% 1:18.58 51 2 0 0- 0 132M 1207M
0 kernel_tas 70.4% 1:20.15 51 2 0 0 0 132M 1207M
0 kernel_tas 67.4% 1:22.02 51 2 0 0 0 132M 1207M
0 kernel_tas 71.1% 1:23.94 51 2 0 0 0 132M 1207M
0 kernel_tas 69.5% 1:25.93 51 2 0 0 0 132M 1207M

[Simon]

Originally Posted by initou 

Config: MacBook Air 1.6 GHz... What the hell ?
...

Try it again, but this time w/o file transfer over a wireless network.

[MacosNerd]

here's mine
0 kernel_tas 5.5% 3:17:33 60 2 0 0- 0 243M 1818M
0 kernel_tas 5.5% 3:17:33 60 2 0 0 0 243M 1818M
0 kernel_tas 4.9% 3:17:34 60 2 0 0 0 243M 1818M
0 kernel_tas 5.6% 3:17:34 60 2 0 0 0 243M 1818M
0 kernel_tas 5.5% 3:17:34 60 2 0 0 0 243M 1818M

[Hg2491]

MacBook 1.83 Core Duo

0 kernel_tas 3.0% 19:57.00 50 2 0 0B- 0B 107M+ 1.06G
0 kernel_tas 3.1% 19:57.06 50 2 0 0B 0B 107M 1.06G
0 kernel_tas 1.8% 19:57.10 50 2 0 0B 0B 107M 1.06G
0 kernel_tas 1.6% 19:57.13 50 2 0 0B 0B 107M- 1.06G-
0 kernel_tas 1.6% 19:57.17 50 2 0 0B 0B 107M 1.06G

Having Safari, MSN Messenger, iCal, Transmission and obviously Terminal opened.