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 IE_Armand,

    IE_Armand IE_Armand Dec 17, 2013 2:42 PM in response to HalexPereira
    Level 1 (5 points)
    Dec 17, 2013 2:42 PM in response to HalexPereira

    Well just wanted to confirm. Having already gone back to 10.8, thought I would try a move to 10.9.1...no luck on my Macbook Air Mid 2013. Still getting 100%+ kernal_task after coming out of sleep.

     

    It has to be software becuase if it was hardware I would see the issue in 10.8 but I dont.

     

    A trip to the Apple store is on the cards after Xmas. Worst bug I've seen on any OS for a long long time.

  • by joeyjohnson,

    joeyjohnson joeyjohnson Dec 17, 2013 3:59 PM in response to IE_Armand
    Level 1 (12 points)
    Photos for Mac
    Dec 17, 2013 3:59 PM in response to IE_Armand

    Thats a useful post, thanks for sharing. Please update us after your trip to the buymoreanddon'texpectustocarewhenitgoeswrong store.

  • by DJWebDUck,

    DJWebDUck DJWebDUck Dec 17, 2013 7:19 PM in response to HalexPereira
    Level 1 (5 points)
    Dec 17, 2013 7:19 PM in response to HalexPereira

    After days of googling, I finally found a working solution:

     

         Mavericks CPU System Spikes When Unplugged

     

    It worked for me. Hopefully it'll work for a few of you.

  • by Finalterminator,

    Finalterminator Finalterminator Dec 18, 2013 6:01 PM in response to HalexPereira
    Level 1 (0 points)
    Mac OS X
    Dec 18, 2013 6:01 PM in response to HalexPereira

    I'm pretty sure my problem is caused by apple new earphone (The one comes with Iphone 5S, which can control the volume of macbook). Other earphones do not have the same issue. Problem arises when I wake up macbook air with the apple earphone plugged during sleep (And it seems problem arise only after I used the earphone to control volume and then let macbook sleep). Simplying unplugging the earphone as someone suggests does not work for me.

     

    How to solve:

    1. Unplug apple earphone

    2. Insert another earphone (whatever earphone, not the apple new one which can control the volume)

    3. Closing the lids of macbook air for 5-10 sec

    4. Open the lid--> problem solved.

  • by thewusman,

    thewusman thewusman Dec 18, 2013 9:33 PM in response to HalexPereira
    Level 1 (0 points)
    Dec 18, 2013 9:33 PM in response to HalexPereira

    I came across this thread searching for help on the kernel_panic issue:

     

                                                                        

     

    https://discussions.apple.com/message/24026834#24026834

     

    Hutch51 wrote: I'm willing to bet it's not the battery monitor.  I've been able to reproduce the issue and reproduce the fix.  If I'm listening to music—iTunes, Spotify, Pandora—with or without headphones, and the computer sleeps, the kernal_task process goes to about 100% and stays there.  That drops my battery from 10-12 hours on a full charge to somewhere near 4-5 hours.  You can check that by pulling up the Activity Monitor and going to the CPU tab.  You should see the kernal_task process running around 100%.  To fix it, I close the laptop, wait five seconds, unplug my headphones (if I'm using them) or plug my headphones in (if I'm not using them), wait five seconds again, and then open the laptop.  100% of the time, this fixes the problem and I can watch the kernal_task CPU usage drop from 100% to <2%.

     

    Also, you can download Coconut Batter to make sure that your battery isn't malfucntioning.  It should be >6300 mAh for a 13" rMBP.  If it's significantly below that, you might have gotten a bum battery.

     

    Good luck.

     

                                                               

     

    I have exactly the same observations as Hutch and others with the kernel_panic CPU bug.

     

    If Spotify is running and my late 2013 rMBP 13" goes to sleep, there is a 50/50 chance that, upon wake, kernel_task will go AWOL and use 100% of a core.

     

    Closing the lid for 5s then opening solves the issue, or:

     

    Closing spotify before sleep state seems to eliminate the issue.

     

    Hope there is a fix soon. Crazy bug this.

     

    Boom was also a culprit but I uninstalled that. Perhaps Boom altered the kext permanently in which case I'm considering a fresh install.

     

     


  • by John_Raz,

    John_Raz John_Raz Dec 19, 2013 3:50 AM in response to HalexPereira
    Level 1 (0 points)
    Dec 19, 2013 3:50 AM in response to HalexPereira

    Like version 10.9, i have use the AppleHDA from 10.8.5 on my MacBookAir mid 2013 and the problem is now solve in 10.9.1.

    I have create an archive with the driver and the tool to install it easily.

    Hope this will help.

  • by mdxico,

    mdxico mdxico Dec 19, 2013 4:37 PM in response to John_Raz
    Level 1 (0 points)
    Dec 19, 2013 4:37 PM in response to John_Raz

    Hey John, very useful! It's a great solution, it worked for me.

     

    Thank you by sharing this fix.

  • by thewusman,

    thewusman thewusman Dec 19, 2013 9:04 PM in response to John_Raz
    Level 1 (0 points)
    Dec 19, 2013 9:04 PM in response to John_Raz

    Confirmed - does not work for late 2013 rMBP with Haswell. You will lose internal speakers / sound output and only Airplay speakers will be visible.

     

    Thanks for this though - rolling back makes sense as a temporary solution.

  • by drewrob26,

    drewrob26 drewrob26 Dec 21, 2013 5:18 PM in response to HalexPereira
    Level 1 (0 points)
    Dec 21, 2013 5:18 PM in response to HalexPereira

    I just got a 13" rMBP late 2013 and am having the same issue.  I am using an external monitor which has audio out via HDMI and a regular set of headphones (without audio controls or mic).  I hope apple releases a fix very soon, it's annoying having to stand on one foot to get your CPU usage at a normal level.

  • by Cyber Wu,

    Cyber Wu Cyber Wu Dec 21, 2013 7:09 PM in response to drewrob26
    Level 1 (0 points)
    Dec 21, 2013 7:09 PM in response to drewrob26

    I have just confirmed that this will not happen when using an non-Apple headset.

    At least on my late-mid MBA 2013 13'.

     

    PS: This is ridiculous, Apple is just going to leave this problem alone??

    It seems to me that it's so easy to reproduce, and so many folks has officially reported the bug.

    the only explanation is that they don't care.

  • by erfarw,

    erfarw erfarw Dec 22, 2013 3:17 AM in response to HalexPereira
    Level 1 (0 points)
    Dec 22, 2013 3:17 AM in response to HalexPereira

    Same problem here.

    Whenever I wake my computer up from sleep, I get 100% CPU (Kernel_task). Only a reboot will clean things up.

    No headset is plugged.

  • by jodasopa,

    jodasopa jodasopa Dec 23, 2013 7:33 AM in response to HalexPereira
    Level 1 (0 points)
    Dec 23, 2013 7:33 AM in response to HalexPereira

    Same Problem here. Bought this book to get optimal battery life and now this ...

     

    Battery life is down to 6 hours due to 100% 1-core usage by kernel_task.

     

    Apple do something!

     

    This happens no matter if power is connected or not as soon as the book wakes from sleep.

     

    Reboot solves this in some cases.

  • by Mikeruoc,

    Mikeruoc Mikeruoc Dec 23, 2013 7:53 AM in response to jodasopa
    Level 1 (0 points)
    Dec 23, 2013 7:53 AM in response to jodasopa

    I have been having this same problem also. No headphone but computer wakes up and kernal_task 98 to 100%. I seem to have found a pattern for me. If I close Google Chrome and put the laptop to sleep and then use Safari no issues. If I leave Chrome open and put the laptop to sleep after doing anything that uses sound (watch a yourtube or anything that has sound from a web page) the problem happens. I have gone 3 days now with just Safari and no issues. Others may want to try.

     

    Thanks

  • by awellis,

    awellis awellis Dec 23, 2013 7:59 AM in response to jodasopa
    Level 1 (0 points)
    Dec 23, 2013 7:59 AM in response to jodasopa

    I had the same problem (Macbook Pro 13" Retina late 2013). When waking from sleep with headphones connected, kernel_task used 100% CPU.

     

    I've just been on the phone with Apple Support, and they had me reboot in recovery mode (Command-R during startup), repair the disk, and then start in Safe Boot mode (Shift during startup), then reboot normally.

     

    I can't reproduce the problem anymore, waking from sleep with headphones plugged in seems to be fine now. Will post again if problem returns, but it seems to have been resolved.

  • by Sharp-man,

    Sharp-man Sharp-man Dec 23, 2013 9:10 AM in response to awellis
    Level 1 (59 points)
    iPhone
    Dec 23, 2013 9:10 AM in response to awellis

    Unfortunately, this did not resolve the issue on my same model (MBPro 13" Retina, late 2013 - 256GB model). I am using Bose QC15 headphones with the Apple remote cord.

     

    I am still seeing a sudden kernel_task spike (100%+) when the computer is awakened from sleep. Unplugging my headphones makes the usage go back to normal (1-2%).

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