6 Replies Latest reply: Nov 15, 2005 6:21 PM by Bill Leser
Bill Leser Level 1 Level 1 (35 points)
Anyone have an idea what "kernal_task (0)" is and why it would be taking up 0ver 65% of my of my CPU?
Needless to say my system usage is over 90%, when usually it's down in the 10 - 20 % range.

Quicksilver G4 850Mhz X2, Mac OS X (10.4.3)
  • Edwin Sneller Level 4 Level 4 (3,495 points)
    The "kernel_task" is the core of the OS. It handles everything from managing multi-tasking to networking. When it is busy, that is usually because it is doing something at the request of one or more applications - which often are idle, waiting for the kernel to finish servicing their requests.
  • Dean Pahl Level 4 Level 4 (3,870 points)
    Hi, Bill and Edwin, et.al.

    Bill, Edwin has answered your question accurately.

    I'm posting to add a few things, FYI.

    The "kernel" is, in the simplest terms, the "guts" of any Operating System — not just OS X. Here's an article in Wickipedia that describes computer architecture, and the kernel specifically. The Kernel Programming Guide is an extensive document about this that's available from the Apple Developer Connection (ADC), if you're interested in exploring the details.

    On a more immediately practical level, the fact that the kernel_task that shows up in Activity Monitor has a Process ID (PID) of 0 illustrates that it was the first "process" that loaded. In fact, this is actually indicative of many tasks — which aren't accessible from the GUI. For example, if you double-click on kernel_task(0) to open a specific window for it in Activity Monitor, you may note that the Sample and Quit options aren't available. We can't quit it for a very good reason: everything would go haywire.

    So... as Edwin has implied, wait on the kernel_task to complete its activities; things should right themselves shortly. If they don't, you may want to do a normal restart — and check in your system.log, e.g., using Console (/Applications/Utilities/Console) to see whether there're entries that help you to discern an explanation.

    If this behavior becomes chronic, please post back — hopefully, with specific description of the circumstances, what you've tried, and recent log entries that may help with troubleshooting.

    Good luck!
  • Bill Leser Level 1 Level 1 (35 points)
    This has been going on all day - slow computer response, etc. I've tried rebooting (warm and cold), repairing permissions, disk repair and turning off my external firewire HD. This happened once before in 10.4.2 but was able to fix the problem in terminal by forcing the prebindings to update with:
    sudo update_prebinding -root / -force
    Unfortunately that didn't work either.

    The last message in the console is:
    Nov 15 16:03:04 Macintosh Extractor[176]: Profile: Mac_NPF
    Nov 15 16:03:04 Macintosh Extractor[176]: Could not upload /var/tmp/tmp.15.Vfnhjz. Error: [Upload Failed: Server Busy]

    Any suggestions?
  • Bill Leser Level 1 Level 1 (35 points)
    Finally found the problem. I rebooted again and this time watched the console. It seems there was a fax stuck in the machine somehow - somewhere. I did the brute force thing of using spotlight to find find all the fax related plists, logs, apps etc and trashed them.
    I rebooted again and lo and behold my CPU usage is back to normal, spotlight is indexing my disks again and programs are booting and running normally.

    Thanks to all for their help.

  • Dean Pahl Level 4 Level 4 (3,870 points)
    Hi again, Bill —

    Thanks for posting back to "close the loop."

    And congrats on figuring out a way to get things working — "brute force" or not!

    Good to hear that monitoring Console helped your troubleshooting and eventual diagnosis. Fwiw, I couldn't figure out anything useful from the entries you'd posted. Goes to show that Discussions can sometimes help "to prime the pump" — but it's often ~impossible to discern from afar what potentially key factors are contributing to a problem.

  • Bill Leser Level 1 Level 1 (35 points)
    I try and leave a note as to how I fixed the problem whenever I do pose a question. Or I'll open a topic with a good header so some other poor slob whose also been a having a heart to heart talk with thier CPU can easily find my solution if their problem is simuliar.
    I'm an on again, off again contributer to the discussions. I used to be really heavy in the FCP and other movie discussions, but then that nasty thing called a "job" started to interfere.
    Thanks again for the suggestion about console. I'd forgotten about it.
    My computer also appreciates because I was getting out the solder irons and chip pullers!