How to solve kernel_task high CPU usage?

[Douglas Barnes]

Okay, I seem to have solved the kernel_task PCU drain using this method I stumbled across on the web.

1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done
I hope this helps.

Only problem now is the battery won't register, new or old and the fan is running 100% of the time.

Updating to El Cap reinstalls the offending .plist file, and tacks on "System Integrity Protection" to make sure you are unable to fix your MacBook. Here's the way around that.

1. Reboot and hold Command + r after the chime. (This should take forever and a day, thanks to the kernel_task issue.)
2. Go to Utilities > Terminal
3. In the terminal, type the following: csrutil disable; reboot
4. Proft

 

[Grenskie]

Okay, I seem to have solved the kernel_task PCU drain using this method I stumbled across on the web.

1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done
I hope this helps.

Only problem now is the battery won't register, new or old and the fan is running 100% of the time.

How exactly did you get OS X to allow you to modify that file I keep getting a pop up that says that file cannot be modified or deleted because it is required by OS X

 

[Douglas Barnes]

How exactly did you get OS X to allow you to modify that file I keep getting a pop up that says that file cannot be modified or deleted because it is required by OS X

Read my post above yours.

 

[A Fish Out Of Water]

I think the method worked for me, cause it seems like it's running faster, but when I check Activity Moniter, it still says that kernal_task is running at the same level. Did it not work, because it seems like it may have worked, but I can't tell.

 

[fcurrie21]

oh my god. Thank you ever so much to fantasticbobski and Douglas Barnes. I don't know how it worked, but it has! I am experienced in fixing mainly PCs and on this MacBook I have changed the HDD to an SSD, changed the hard drive cable as I read that this is a common and difficult to diagnose fault on the early 2011 MacBook Pros and finally this trick worked! Went from 98% system usage at rest to about 4%! Fan was running full blast before and still is now so i've got that to work on. But thanks ever so much, I'm going to have one happy girlfriend.

Cheers.

 

[EkimReldar]

Mike,

I had no right to do this but, I copy/pasted this

sudo mv /System/Library/Extensions/AppleSMCLMU.kext ~

and now my computer has more beach ball time out then ever. Sorry to ask but can you tell me how to undo this command?

Thanks

Solved the problem on 2013 MacBookPro

OK, so I have a 2013 late model MBP, and I have been having this issue for some time now ... In my case, when I run the hardware diagnostics, it says that I *MAY* have a faulty PMU or PCU or power whatever logic board thing-a-ma-jig ... However, I had to replace my screen a few months back because I dropped the MBP and cracked my screen, and the screen I bought from ebay had some of the wires cut and I didn't read the fine print before I made the purchase (it was only $200 and other than the wires being cut (not the video cable, but the other ones) it works great! But since I put this screen in, I've been having the high CPU utilization in my kernel_task process and my MBP ran slower than molasses ...

Well, after much experimentation, research, trial and error, I finally solved the problem... here is what you need to do:

Open up terminal (If you don't know what that is, you have no business doing this in the first place)...

type (or copy and paste from here):

sudo mv /System/Library/Extensions/AppleSMCLMU.kext ~

that will move it to your parent home folder

Reboot!

I also have AppleIntelCPUPowerManagementClient.kext and NullCPUPowerManagement.kext in my home folder, but I'm 99.999% positive that the problem went away after moving that SMCLMU kext file out of the extensions folder and re-booting. I believe that is the file that reports the mis information to the kernel which then freaks the heck out for some reason - in my opinion, the way OSX responds to a bad sensor is a very poor way to respond to a bad sensor ... sure, lets make the computer almost unusable so that the user will pay us to fix it for them ... there are times when hardware can be faulty, yet there is no risk to the computer at all, it doesn't mean that your laptop will never reach temperature levels which that sensor monitors which will put your laptop in danger ... in fact, in my case, the sensor readings were pinging at -128 degrees ... you'd think that Apple would realize that -128 is indicative of a faulty sensor especially when the other sensors are reading normal temperatures ... so why dumb down the computer when it's obvious that the sensor isn't actually providing a reading which indicates danger for the hardware... that the sensor itself is actually the problem so no need to go to extremes and make the computer run slower... sensors are there as a secondary watch over the hardware, the user being the first ... so again ... why design an operating system to run slow when a sensor has merely gone bad? Could you imagine if car manufacturers made your car go no faster than 20 miles per hour because of a bad o2 sensor???? It's a piss poor design call on Apple's part and they really need to fix it.

Good luck everyone!

Mike Sims

----------



I forgot to mention that I've been using my MBP for over 15 hours now since implementing the solution I posted without any slow down issues or high CPU utilization what so ever ... that is a world record for this MBP as I have been dealing with this problem for MONTHS ... it's like having a new mac now.

 

[EkimReldar]

By the way, I have an early 2011 macbook pro 15" with 16 GB ram

 

[osart11]

Hello,

I cannot find IOPlatformPluginFamily.kext
can u please help?

 

[Kix_]

I've had the same experience (kernel_task consuming up to 500%+ CPU time according to Activity Monitor), and here's how I solved it. But first, some things worth pointing out:

The kernel_task is a core operating system component which basically manages things such as communication between the hardware and the OS. If the kernel_task is eating too much CPU time, it's usually indicative of something wrong with the hardware.

.kext files are Kernel EXTensions. They're analogous to Windows drivers such that they allow the OS to communicate properly with the hardware components.

As you might figure out, disabling kext files (like some guides advise you to) is a very reckless move and a terrible idea. Essentially, if you remove a kext file, you're removing a layer of communications between the OS and hardware. The ACPI___.kext file for example, deals with system power, battery management, and voltage levels. As you might imagine, if you were to silence this kext file, you're exposing your system to a ton of dangerous stuff relating to power management (worst case would be a fried battery or motherboard).

Remember how high kernel_task CPU usage usually means something in your hardware gone awry? In my case, the fans were not spinning properly, thus making my system overheat and causing the kernel_task to panic. This happened because I previously installed a tool called Macs Fan Control which let me max out my fan speeds at all times, and forgot to turn it on. As a result, my fan speeds were locked at a low 1000-ish RPM while trying to play a game, and as you can imagine, it heated up my system pretty well. I turned on Macs Fan Control and set my RPM to max, and the kernel_panic task chilled out. If I disabled my kext file for sensor control or fans, the kernel_task would probably have chilled all the same BUT with the added danger of me overheating my system.

Some things worth trying:
- Disable peripherals (a faulty USB device pulling higher voltage might be an ideal culprit, as well as an HDMI peripheral gone bonkers)
- Check temperatures and fan speeds (this is what happened to mine)
- Check virtualization tools (such as Parallels and VMWare Fusion; sometimes they cause the kernel_task due to the way they handle system resources)
- Try a restart and SMC refresh

Cheers
Kix_

 

[EkimReldar]

Can anyone help me, I need to REVERSE this copy/paste.

Code:
sudo mv /System/Library/Extensions/AppleSMCLMU.kext ~

I copied it in and it is wreaking havoc on my system. Is there any way to undo this?

 

[EkimReldar]

Mike,

I had no right to do this but, I copy/pasted this

sudo mv /System/Library/Extensions/AppleSMCLMU.kext ~

and now my computer has more beach ball time out then ever. Sorry to ask but can you tell me how to undo this command?

Thanks

 

[Weaselboy]

First let's make sure the file is still where you moved it. Click the Desktop the hit shift-command-g (all three at once) and enter ~ in the box then hit return. That should open a Finder window at the base of your user folder. Is the file AppleSMCLMU.kext still there? If it is, leave it alone and try the command below to put it back where it was. Reboot after.

sudo mv ~/AppleSMCLMU.kext /System/Library/Extensions/

 

[EkimReldar]

I went to my user folder, did not see appleSMCLMU.kext

file://localhost/Users/michaelradler/Desktop/Screen%20Shot%202015-12-26%20at%2011.29.39%20PM.png

This is what I am basically seeing when I arrive there

 

[EkimReldar]

Sorry, I realized I need to enter ~ in the box and hit return, just did, still not there

 

[EkimReldar]

This is the window I see

 

[EkimReldar]

I went there and it was not there…I guess that's not a good start huh? Any other ideas? Thanks

First let's make sure the file is still where you moved it. Click the Desktop the hit shift-command-g (all three at once) and enter ~ in the box then hit return. That should open a Finder window at the base of your user folder. Is the file AppleSMCLMU.kext still there? If it is, leave it alone and try the command below to put it back where it was. Reboot after.

sudo mv ~/AppleSMCLMU.kext /System/Library/Extensions/

 

[EkimReldar]

If you are asking me sorry, wrong guy, anyone else able to help osart11?

Hello,

I cannot find IOPlatformPluginFamily.kext
can u please help?

 

[Weaselboy]

I went there and it was not there…I guess that's not a good start huh? Any other ideas? Thanks

Nope... that first command would have moved the file to ~ which is the base of your users folder, and from your screenshots it looks like it is not there, so you have nothing to copy back. You must have deleted the file at some point.

At this point you will need to command-r boot to recovery and just reinstall the OS to get the file back. Don't erase anything, just reinstall and all your data will still be there.

You should backup first though just to be safe.

 

[EkimReldar]

Thanks so much, I'll d that now and maybe a clean OS will solve some other issues I'm sure I had going on. Will update this thread after to report my progress, thanks again.

Nope... that first command would have moved the file to ~ which is the base of your users folder, and from your screenshots it looks like it is not there, so you have nothing to copy back. You must have deleted the file at some point.

At this point you will need to command-r boot to recovery and just reinstall the OS to get the file back. Don't erase anything, just reinstall and all your data will still be there.

You should backup first though just to be safe.

 

[leez]

Properly clean your vents.

See my thread here: https://forums.macrumors.com/threads/slow-macbook-pro-properly-clean-the-vents.1947229/

 

[squamish]

Okay, I seem to have solved the kernel_task PCU drain using this method I stumbled across on the web.

1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done
I hope this helps.

Only problem now is the battery won't register, new or old and the fan is running 100% of the time.

My battery was/ is dying. Suddenly my machine slowed to a crawl but this worked for me.! Thanks.

 

[colshefsky]

This method works!



I had the exact same problem with the battery and fan, and CPU usage was 177%. This worked IMMEDIATELY after reboot, noticeable right away, and did not cause any other problems. Thank-you for posting this solution.

Works for me too! Thanks everyone! My CPU is as good as new

 

[zeusthedino]

Im getting tired of my macbook pro 2011 17 inch getting hot so quickly. I changed the thermal paste and so now it doesnt reach 90c as it used to, but it still gets very hot which is annoying because the keyboard becomes hot too.
Should I do the .kext fix? I need a fix for this heat problem

 

[VanessaKing]

sudo mv /System/Library/Extensions/AppleSMCLMU.kext ~

that will move it to your parent home folder

Reboot!


Mike Sims

I've been using mine for 24 hours since moving this one out of my extensions folder, and it's working great! Apparently it's a sensor extension for MBP 3,1 + 4,1 + 5,1 and since I've got a 6,1 MBP, it was completely unnecessary. Thanks for the great tip, Mike!!

 

[VanessaKing]

I've been using mine for 24 hours since moving this one out of my extensions folder, and it's working great! Apparently it's a sensor extension for MBP 3,1 + 4,1 + 5,1 and since I've got a 6,1 MBP, it was completely unnecessary. Thanks for the great tip, Mike!!

Quick update, I'm still kernel panic-free, but I think this kext handles the keyboard backlight sensor. Since I removed it, my keyboard's backlight doesn't work—not manually or automatically. I'm happy to type in brighter light though, if it means no more crashing, overheating, runaway fanning.