You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

User profile for user: kuerbiskopf
kuerbiskopf Author
User level: Level 1
2 points

kernel_task using 100% CPU

Hey guys,

my Macbook Air 2013 is two month old, and ever since I upgraded to Mavericks, kernel_task will sometimes eat up to 100% of my CPU. The system will remain usable, but battery life goes down significantly. A reboot will solve this issue for a time, so will quitting all applications in the menu bar, but some time later kernel_task will return in full force.

Things I did and checked:

  • no faulty sensor
  • hardware check
  • no overheating
  • no app seems to be directly responsible
  • SMC and NVRAM/PRAM reset
  • repaired disk permissions and repaired SSD through the recovery partition
  • not yet reinstalled Mavericks
  • no issues in safe mode, at least yet


I suspect that this is caused by some kernel extension, but I have no idea which one and how to fix that.

I have in the past installed: some fishy USB to Ethernet driver, BOOM (system wide equilizer), LaTEX and probably more things.

MacBook Air, OS X Mavericks (10.9)

Posted on Nov 3, 2013 6:30 AM

Reply
Question marked as Top-ranking reply
User profile for user: Linc Davis
Linc Davis
User level: Level 10
209,649 points

Posted on Nov 3, 2013 2:44 PM

Please read this whole message before doing anything.

This procedure is a diagnostic test. It won’t solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.

Third-party system modifications are a common cause of usability problems. By a “system modification,” I mean software that affects the operation of other software — potentially for the worse. The following procedure will help identify which such modifications you've installed. Don’t be alarmed by the complexity of these instructions — they’re easy to carry out and won’t change anything on your Mac.


These steps are to be taken while booted in “normal” mode, not in safe mode. If you’re now running in safe mode, reboot as usual before continuing.


Below are instructions to enter some UNIX shell commands. The commands are harmless, but they must be entered exactly as given in order to work. If you have doubts about the safety of the procedure suggested here, search this site for other discussions in which it’s been followed without any report of ill effects.


Some of the commands will line-wrap or scroll in your browser, but each one is really just a single line, all of which must be selected. You can accomplish this easily by triple-clicking anywhere in the line. The whole line will highlight, and you can then copy it. The headings “Step 1” and so on are not part of the commands.


Note: If you have more than one user account, Step 2 must be taken as an administrator. Ordinarily that would be the user created automatically when you booted the system for the first time. The other steps should be taken as the user who has the problem, if different. Most personal Macs have only one user, and in that case this paragraph doesn’t apply.


Launch the Terminal application in any of the following ways:


☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)


☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.


☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.


When you launch Terminal, a text window will open with a line already in it, ending either in a dollar sign (“$”) or a percent sign (“%”). If you get the percent sign, enter “sh” and press return. You should then get a new line ending in a dollar sign.


Step 1


Triple-click anywhere in the line of text below on this page to select it:

kextstat -kl | awk '!/com\.apple/{printf "%s %s\n", $6, $7}' | open -ef

Copy the selected text to the Clipboard by pressing the key combination command-C. Then click anywhere in the Terminal window and paste (command-V). I've tested these instructions only with the Safari web browser. If you use another browser, you may have to press the return key after pasting. A TextEdit window will open with the output of the command. If the command produced no output, the window will be empty. Post the contents of the TextEdit window (not the Terminal window), if any — the text, please, not a screenshot. You can then close the TextEdit window. The title of the window doesn't matter, and you don't need to post that. No typing is involved in this step.

Step 2


Repeat with this line:

{ sudo launchctl list | sed 1d | awk '!/0x|com\.(apple|openssh|vix\.cron)|org\.(amav|apac|cups|isc|ntp|postf|x)/{print $3}'; echo; sudo defaults read com.apple.loginwindow LoginHook; echo; sudo crontab -l; } 2> /dev/null | open -ef

This time you'll be prompted for your login password, which you do have to type. Nothing will be displayed when you type it. Type it carefully and then press return. You may get a one-time warning to be careful. Heed that warning, but don't post it. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator.


Note: If you don’t have a login password, you’ll need to set one before taking this step. If that’s not possible, skip to the next step.


Step 3

{ launchctl list | sed 1d | awk '!/0x|com\.apple|org\.(x|openbsd)/{print $3}'; echo; crontab -l 2> /dev/null; } | open -ef

Step 4

ls -A /e*/{cr,la,mach}* {,/}Lib*/{Ad,Compon,Ex,Fram,In,Keyb,La,Mail/Bu,P*P,Priv,Qu,Scripti,Servi,Spo,Sta}* L*/Fonts .la* 2> /dev/null | open -ef

Important: If you formerly synchronized with a MobileMe account, your me.com email address may appear in the output of the above command. If so, anonymize it before posting.


Step 5

osascript -e 'tell application "System Events" to get name of login items' | open -ef

Remember, steps 1-5 are all copy-and-paste — no typing, except your password. Also remember to post the output.


You can then quit Terminal.

View in context
73 replies
Question marked as Top-ranking reply
User profile for user: Linc Davis
Linc Davis
User level: Level 10
209,649 points

Nov 3, 2013 2:44 PM in response to kuerbiskopf

Please read this whole message before doing anything.

This procedure is a diagnostic test. It won’t solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.

Third-party system modifications are a common cause of usability problems. By a “system modification,” I mean software that affects the operation of other software — potentially for the worse. The following procedure will help identify which such modifications you've installed. Don’t be alarmed by the complexity of these instructions — they’re easy to carry out and won’t change anything on your Mac.


These steps are to be taken while booted in “normal” mode, not in safe mode. If you’re now running in safe mode, reboot as usual before continuing.


Below are instructions to enter some UNIX shell commands. The commands are harmless, but they must be entered exactly as given in order to work. If you have doubts about the safety of the procedure suggested here, search this site for other discussions in which it’s been followed without any report of ill effects.


Some of the commands will line-wrap or scroll in your browser, but each one is really just a single line, all of which must be selected. You can accomplish this easily by triple-clicking anywhere in the line. The whole line will highlight, and you can then copy it. The headings “Step 1” and so on are not part of the commands.


Note: If you have more than one user account, Step 2 must be taken as an administrator. Ordinarily that would be the user created automatically when you booted the system for the first time. The other steps should be taken as the user who has the problem, if different. Most personal Macs have only one user, and in that case this paragraph doesn’t apply.


Launch the Terminal application in any of the following ways:


☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)


☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.


☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.


When you launch Terminal, a text window will open with a line already in it, ending either in a dollar sign (“$”) or a percent sign (“%”). If you get the percent sign, enter “sh” and press return. You should then get a new line ending in a dollar sign.


Step 1


Triple-click anywhere in the line of text below on this page to select it:

kextstat -kl | awk '!/com\.apple/{printf "%s %s\n", $6, $7}' | open -ef

Copy the selected text to the Clipboard by pressing the key combination command-C. Then click anywhere in the Terminal window and paste (command-V). I've tested these instructions only with the Safari web browser. If you use another browser, you may have to press the return key after pasting. A TextEdit window will open with the output of the command. If the command produced no output, the window will be empty. Post the contents of the TextEdit window (not the Terminal window), if any — the text, please, not a screenshot. You can then close the TextEdit window. The title of the window doesn't matter, and you don't need to post that. No typing is involved in this step.

Step 2


Repeat with this line:

{ sudo launchctl list | sed 1d | awk '!/0x|com\.(apple|openssh|vix\.cron)|org\.(amav|apac|cups|isc|ntp|postf|x)/{print $3}'; echo; sudo defaults read com.apple.loginwindow LoginHook; echo; sudo crontab -l; } 2> /dev/null | open -ef

This time you'll be prompted for your login password, which you do have to type. Nothing will be displayed when you type it. Type it carefully and then press return. You may get a one-time warning to be careful. Heed that warning, but don't post it. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator.


Note: If you don’t have a login password, you’ll need to set one before taking this step. If that’s not possible, skip to the next step.


Step 3

{ launchctl list | sed 1d | awk '!/0x|com\.apple|org\.(x|openbsd)/{print $3}'; echo; crontab -l 2> /dev/null; } | open -ef

Step 4

ls -A /e*/{cr,la,mach}* {,/}Lib*/{Ad,Compon,Ex,Fram,In,Keyb,La,Mail/Bu,P*P,Priv,Qu,Scripti,Servi,Spo,Sta}* L*/Fonts .la* 2> /dev/null | open -ef

Important: If you formerly synchronized with a MobileMe account, your me.com email address may appear in the output of the above command. If so, anonymize it before posting.


Step 5

osascript -e 'tell application "System Events" to get name of login items' | open -ef

Remember, steps 1-5 are all copy-and-paste — no typing, except your password. Also remember to post the output.


You can then quit Terminal.

Reply
User profile for user: kuerbiskopf
kuerbiskopf Author
User level: Level 1
2 points

Nov 3, 2013 2:57 PM in response to Linc Davis

Step 1:

com.globaldelight.driver.BoomDevice (1.1)


Step 2:

org.macosforge.xquartz.privileged_startx

com.splashtop.streamer-daemon

com.microsoft.office.licensing.helper

com.DesignScience.DSMTTool

com.bjango.istatmenusdaemon

com.anchorfree.ajaxserver

com.adobe.SwitchBoard


Step 3:

com.globaldelight.BoomDaemon.46144

com.inmethod.AirVideoServerHD.1264

com.getdropbox.dropbox.24496

com.alfredapp.Alfred.24672

com.hegenberg.BetterTouchTool.25904

com.surteesstudios.Bartender.25552

com.pilotmoon.popclip.32240

org.herf.Flux.33120

com.mediaatelier.CheatSheet.27664

com.globaldelight.Boom.27136

com.kuvva.KuvvaHelper

com.paragon.extfs.trial

org.macosforge.xquartz.startx

org.glimmerblocker.updater

com.splashtop.streamer-for-user

com.bjango.istatmenusagent

com.google.keystone.user.agent


Step 4:

/Library/Components:



/Library/Extensions:

ATTOCelerityFC8.kext

ATTOExpressSASHBA2.kext

ATTOExpressSASRAID2.kext

ArcMSR.kext

CalDigitHDProDrv.kext

HighPointIOP.kext

HighPointRR.kext

PromiseSTEX.kext

SoftRAID.kext



/Library/Frameworks:

AEProfiling.framework

AERegistration.framework

AudioMixEngine.framework

MT6Lib.framework

NyxAudioAnalysis.framework

PluginManager.framework

iTunesLibrary.framework



/Library/Input Methods:



/Library/Internet Plug-Ins:

Default Browser.plugin

Quartz Composer.webplugin

QuickTime Plugin.plugin

SharePointBrowserPlugin.plugin

SharePointWebKitPlugin.webplugin

nsIQTScriptablePlugin.xpt



/Library/Keyboard Layouts:



/Library/LaunchAgents:

com.adobe.AAM.Updater-1.0.plist

com.bjango.istatmenusagent.plist

com.splashtop.streamer-for-root.plist

com.splashtop.streamer-for-user.plist

com.teamviewer.teamviewer.plist

com.teamviewer.teamviewer_desktop.plist

org.glimmerblocker.updater.plist

org.macosforge.xquartz.startx.plist



/Library/LaunchDaemons:

com.DesignScience.DSMTTool.plist

com.adobe.SwitchBoard.plist

com.anchorfree.ajaxserver.plist

com.bjango.istatmenusdaemon.plist

com.microsoft.office.licensing.helper.plist

com.splashtop.streamer-daemon.plist

com.teamviewer.teamviewer_service.plist

org.macosforge.xquartz.privileged_startx.plist



/Library/PreferencePanes:

GlimmerBlocker.prefPane

NTFSforMacOSX.prefPane

Perian.prefPane

TeXDistPrefPane.prefPane



/Library/PrivilegedHelperTools:

com.DesignScience.DSMTTool

com.microsoft.office.licensing.helper



/Library/QuickLook:

iBooksAuthor.qlgenerator

iWork.qlgenerator



/Library/QuickTime:

AC3MovieImport.component

AppleAVCIntraCodec.component

AppleHDVCodec.component

AppleIntermediateCodec.component

AppleMPEG2Codec.component

AppleProResCodec.component

DVCPROHDCodec.component

FCP Uncompressed 422.component

IMXCodec.component

Perian.component



/Library/ScriptingAdditions:

Adobe Unit Types.osax

BartenderHelper.osax



/Library/Spotlight:

Microsoft Office.mdimporter

iBooksAuthor.mdimporter

iWork.mdimporter



/Library/StartupItems:

ChmodBPF



/etc/mach_init.d:



/etc/mach_init_per_login_session.d:



/etc/mach_init_per_user.d:



Library/Address Book Plug-Ins:

SkypeABDialer.bundle

SkypeABSMS.bundle



Library/Fonts:



Library/Input Methods:

.localized



Library/Internet Plug-Ins:



Library/Keyboard Layouts:



Library/LaunchAgents:

com.apple.AddressBook.ScheduledSync.PHXCardDAVSource.33399528-1E6E-4441-A9F4-8C4 F1069D1D9.plist

com.google.keystone.agent.plist

com.spotify.webhelper.plist



Library/PreferencePanes:



Library/Services:

.localized



Step 5:

Boom, CheatSheet, Flux, PopClip, Bartender, BetterTouchTool, Alfred, Dropbox, Air Video Server HD

Reply
User profile for user: Linc Davis
Linc Davis
User level: Level 10
209,649 points

Nov 3, 2013 3:36 PM in response to kuerbiskopf

Your system is very heavily modified. I suggest you start by uninstalling "Boom."

Any third-party software that doesn't install by drag-and-drop into the Applications folder, and uninstall by drag-and-drop to the Trash, is a system modification.

Whenever you remove system modifications, they must be removed completely, and the only way to do that is to use the uninstallation tool, if any, provided by the developers, or to follow their instructions. If the software has been incompletely removed, you may have to re-download or even reinstall it in order to finish the job.

I never install system modifications myself, and I don't know how to uninstall them. You'll have to do your own research to find that information.

Here are some general guidelines to get you started. Suppose you want to remove something called “BrickMyMac” (a hypothetical example.) First, consult the product's Help menu, if there is one, for instructions. Finding none there, look on the developer's website, say www.brickmyrmac.com. (That may not be the actual name of the site; if necessary, search the Web for the product name.) If you don’t find anything on the website or in your search, contact the developer. While you're waiting for a response, download BrickMyMac.dmg and open it. There may be an application in there such as “Uninstall BrickMyMac.” If not, open “BrickMyMac.pkg” and look for an Uninstall button.

Back up all data before making any changes. You generally have to reboot in order to complete an uninstallation.

If you can’t remove software in any other way, you’ll have to erase and install OS X. Never install any third-party software unless you're sure you know how to uninstall it; otherwise you may create problems that are very hard to solve.

You may be advised by others to try to remove complex system modifications by hunting for files by name, or by running "utilities" that purport to remove software. I don't give such advice. Those tactics often will not work and may make the problem worse.

Reply
User profile for user: kuerbiskopf
kuerbiskopf Author
User level: Level 1
2 points

Nov 13, 2013 9:27 AM in response to kuerbiskopf

Even now, with Boom uninstalled, kernel_task will sometimes still use 100% CPU, but that is very rare. It does ofter coincide with when headphones are plugged in or some sort of sound is playing (doesn't matter what programm). Closing the lid, then plugging the headphones in, opening the Air and then diconnecting the headphones will immeadiately solve this issue. Very weird. I suspect it is bug with the sounddriver/kernel thingy within Mavericks and it is not Boom's fault, but Boom seems to trigger it more often.

Reply
User profile for user: alexisjestevez
alexisjestevez
User level: Level 1
0 points

Nov 18, 2013 2:15 PM in response to kuerbiskopf

I had a similar problem. The error essentially means your computer is out of memory. Most likely, some app/program you're running is buggy and has what's called a memory leak. According to Apple documentation, you need at least 9 GB free for normal operation. You also need enough space left over to allow for growth of your data.


First, reboot. That will temporarily free up some space. Then use Apple's Activity Monitor to learn which program on your computer is the culprit. From your desktop find Activity Monitor (Command+F) and double-click on it. When the Activity Monitor window appears click on the %CPU tab @ the top. This will show the problem app using up the most space. I had to let it run a little while before the problem app appeared and saw how quickly my memory was running out. The problem was a third party app I rarely used, so I deleted it and it's asscociated folders under /Library/Application Support. Did this both in the User library and the Mac HD library. Shut down my laptop and restarted. Problem solved. Cheers.

Reply
User profile for user: northwest291
northwest291
User level: Level 1
5 points

Nov 24, 2013 8:47 AM in response to kuerbiskopf

I recently purchased a new MBPr 2013, and since the first day I have been experiencing problems with the kernel process. After some research I have discovered that the process takes up A LOT of CPU power if:


My headphones are plugged in and I wake my mbp from sleep.


To fix the problem I have to either unplug the headphones, or close the lid for a few seconds.


Clearly there is something wrong with the audio that makes the kernel process go bananas.

Reply

kernel_task using 100% CPU

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.
Learn more Sign up