HalexPereira

Q: kernel_task is using 100% CPU when waking from sleep

Since updating my 13" mid-2013 MacBook Air to Mavericks, there's this issue that's been happening when I wake the computer up from sleep. A proccess called kernel_task uses 100% CPU (a whole core) and hangs there until the computer is restarted. This doesn't make the computer unresponsive, but it kills battery life.

 

So far, I've tried the following:

 

1. Resetting SMC, NVRAM and PRAM: no effect.

2. Safe Boot: the issue doesn't happen.

3. Deleting old apps/plugins: issue persists.

4. Closing all apps doesn't solve issue after it takes place.

5. Repairing permissions: no effect.

6. Apple Diagnostics: no issue found in hardware.

7. No kernel extensions from third-parties are installed (there are 120 kext, according to Terminal, but they all come from Apple).

8. Everything is up to date.

9. Only external plugin installed is Flash.

 

Given these, I reckon it's something software-related. Any tips on solving this would be welcome — things to look for in Console logs would be greatly appreciated.

MacBook Air (13-inch Mid 2013), OS X Mavericks (10.9)

Posted on Oct 28, 2013 12:03 PM

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Q: kernel_task is using 100% CPU when waking from sleep

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  • by srodal,

    srodal srodal Jan 7, 2014 11:16 PM in response to SundanceX
    Level 1 (0 points)
    Jan 7, 2014 11:16 PM in response to SundanceX

    Neither unloading and reloading /System/Library/Extensions/AppleHDA.kext nor the iTunes workaround do anything for me on my 2013 MacBook Air running 10.8.5. As I'm travelling I won't have the option to send my Mac in for repair for a while either... Very disappointed to search for the kernel_task issue and find a lot of workarounds like this one that don't work: http://www.rdoxenham.com/?p=259

     

    Searching google, it seems this has been an issue on various hardware for multiple years. Makes me question buying hardware from Apple again seeing how silent they are on this issue.

  • by John_Raz,

    John_Raz John_Raz Jan 8, 2014 12:51 AM in response to HalexPereira
    Level 1 (0 points)
    Jan 8, 2014 12:51 AM in response to HalexPereira

    If you want to fix the problem on MacBook Air and MacBookPro waiting to Apple to release a new AppleHDA driver, use the method i have describe:

    https://discussions.apple.com/message/24178943#24178943

  • by srodal,

    srodal srodal Jan 8, 2014 1:01 AM in response to John_Raz
    Level 1 (0 points)
    Jan 8, 2014 1:01 AM in response to John_Raz

    I'm not sure I understand, you say you "use the AppleHDA from 10.8.5". Well, I am already running 10.8.5 and I still have the problem occasionally. How would it help to install the driver from 10.8.5 when I'm already running 10.8.5?

  • by John_Raz,

    John_Raz John_Raz Jan 8, 2014 1:24 AM in response to srodal
    Level 1 (0 points)
    Jan 8, 2014 1:24 AM in response to srodal

    I speak about the specific problem on MBA and MBP with AppleHDA driver of mavericks 10.9.0 and 10.9.1, with cpu goes to 100% when using an audio application (with headphone plug in) and the computer go to sleep then wake up.

  • by srodal,

    srodal srodal Jan 8, 2014 1:32 AM in response to John_Raz
    Level 1 (0 points)
    Jan 8, 2014 1:32 AM in response to John_Raz

    My issue is different but with similar symptoms then, when it happens the CPU usage of kernel_task goes to more than 300 %. Sometimes after restarting a couple of times it stops happening for a while.

  • by cyclix86,

    cyclix86 cyclix86 Jan 8, 2014 6:51 AM in response to Marc Bejarano
    Level 1 (0 points)
    Jan 8, 2014 6:51 AM in response to Marc Bejarano

    Unloading and reloading the AppleHDA.kext kernel extension as described above did nothing for me. kernel_task still using ~100% CPU on the primary core after wake from sleep. I'm on the lastest  Mavericks (10.9.1) on a new 2013 Retina MacBook Pro 13".

  • by gattol,

    gattol gattol Jan 8, 2014 6:57 AM in response to cyclix86
    Level 1 (0 points)
    Jan 8, 2014 6:57 AM in response to cyclix86

    Same here.

  • by Jan Teurlings,

    Jan Teurlings Jan Teurlings Jan 8, 2014 8:16 AM in response to gattol
    Level 1 (75 points)
    Jan 8, 2014 8:16 AM in response to gattol

    With me unloading the AppleHDA.kext did drop CPU usage but I did get an error message:

    (kernel) Can't unload kext com.apple.driver.AppleHDA; classes have instances:

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAWidgetCS4208 has 8 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAEngine has 2 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAEngineOutput has 2 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAEngineOutputDP has 1 instance.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAEngineInput has 1 instance.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAStream has 2 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAPath has 5 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAWidget has 2 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDANode has 1 instance.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAPathSet has 5 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAPathControl has 8 instances.

    (kernel)     Kext com.apple.driver.AppleHDA class AppleHDAWidget_80862807 has 2 instances.

    Failed to unload com.apple.driver.AppleHDA - (libkern/kext) kext is in use or retained (cannot unload).

     

    Reloading afterwards worked but I had lost all sound. Only a restart could fix it.

  • by antony-m,

    antony-m antony-m Jan 8, 2014 9:05 AM in response to Jan Teurlings
    Level 1 (0 points)
    Jan 8, 2014 9:05 AM in response to Jan Teurlings

    You can run it with -c flag such as this:

     

         sudo kextunload -c /System/Library/Extensions/AppleHDA.kext

     

    It will terminate all those instances. This fix didn't work for me though.

  • by skycondition,

    skycondition skycondition Jan 8, 2014 3:59 PM in response to HalexPereira
    Level 1 (0 points)
    Jan 8, 2014 3:59 PM in response to HalexPereira

    Problem goes away when I unplug my headphones that have a control.

  • by Prokrastination,

    Prokrastination Prokrastination Jan 9, 2014 3:54 AM in response to antony-m
    Level 1 (0 points)
    Jan 9, 2014 3:54 AM in response to antony-m

    For the record: kextunload without '-c' fixes the problem for me (late 2013 Retina MacBook Pro 13") with the know problem of losing the sound, using the '-c' option does not help.

     

    I hope there will be a final solution soon.

  • by John_Raz,

    John_Raz John_Raz Jan 9, 2014 4:34 AM in response to HalexPereira
    Level 1 (0 points)
    Jan 9, 2014 4:34 AM in response to HalexPereira

    Why are you trying to use non working solution like trying to unload a driver instead of replacing the default driver with one that work like i describe here: https://discussions.apple.com/message/24178943#24178943 ?

  • by Prokrastination,

    Prokrastination Prokrastination Jan 9, 2014 5:38 AM in response to John_Raz
    Level 1 (0 points)
    Jan 9, 2014 5:38 AM in response to John_Raz

    Because someone answered your post with the statement, that the solution does not work on late 2013 MBPs

  • by bausi,

    bausi bausi Jan 9, 2014 6:29 AM in response to John_Raz
    Level 1 (10 points)
    Jan 9, 2014 6:29 AM in response to John_Raz

    seems to work for me!

  • by gattol,

    gattol gattol Jan 9, 2014 6:48 AM in response to bausi
    Level 1 (0 points)
    Jan 9, 2014 6:48 AM in response to bausi

    On late 2013 mbp retina?

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