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

I am seeing the same issue randomly occur every few days... suddenly this kernel_task takes over. No peripherals installed, Mid-2011 Mac Air with Mavericks (from Lion), doing heavily memory & cpu intensive and network intensive tasks running all browsers fully stacked with apps. While this process runs there is also associated sustained SSD activity 6 - 25MB/s. Kernel task is using 1.6GB with FF next at 1GB, 36MB Free. Kernel_task uses 50-130+% CPU, and the fan runs continuously.*

Maybe it's reindexing the disk?

Workaround is to reboot.

Apple,  please fix this issue affecting mission-critical performance of this equipment, or provide a way to diagnose. Thanks.

* Diagnostics from iStat Menu.

I have the exact same issue with late 2013 maxed 13". It only appears when I have both users logged in.

See if this helps: https://www.youtube.com/watch?v=Q8OqdMq98j4

Same issues here on a brand new Macbook Pro. I play guitar, and use the computer to record. Now i cant use headphones. guess I shouldnt have bought this computer. My 2012 Macbook Air runs Mavericks and never had kernel_task issues.                  

I am sure Apple will fix this. You should be happy with your new MBP.

if you are serious about recording with that macbook you may want to get an external sound card/headphone amp anyway instead of using the cheap integrated headphone out. Or just wait for the .1 release to fix this issue.

Well I'm glad I'm not the only one experiencing this. Then again, not so happy. Just noticed it today as my computer came to a crawl. I'm on a 2013 MBAir with the Cinema Display plugged in via Thunderbolt. After I experience this and then restart, my computer will be stuck after the log in screen. It stays this way for an hour or so because I typically just give up and disconnect the Thunderbolt. After that, everything starts up fine. But then when I connect it again (so I can work), I noticed kernel_task eating up over 120% CPU, almost every time. So annoying!

I'm experiencing this as well.  I've got a mid-2013 MacBook Air running 10.9.  I don't use headphones often, nor VLC.  Upon a clean reboot, with no head phones plugged in, if I put the MBA to sleep then open it back then I get the kernel_task 100% issue. 

This is a problem for me because I rely on having a full day's worth of battery life for work.  I upgraded from the 2011 MacBook Air to this one a few months ago specifically for the additional battery life.  Now I'm getting 6 hours, which is less than what I was still getting on my 2011 model.

Alright, I solved my problem! Here's the situation (and thanks for whichever forum I found this solve).

To repeat, I was suffering this problem and my computer was at a crawl. Literally, opening up folders would be a drag just to get its contents listed.

I ran Disk Utlitiy and found a new error: "Live file system repair is not supported". Now, I'm one of those people to run Disk Utility about every other week but usually to fix partitions. I hardly ever run "Repair Disk" but this time I did and I saw this message in bright red which was a problem. So I did what anyone would do and startup in recovery mode and run Disk Utlity there. This time even more errors showed up such as my partition mapping was wrong and all of them were not able to be fixed.

Then I followed instructions to create a bootable Mavericks startup disk onto a USB drive (you can google this or find on one of the other forums). After what felt like eternity, it completed and I booted from the USB drive and was able to fix my Disk.

Anyway, that was this morning and with Activity Monitor running, "kernal_task" never goes above 25%, which still feels like a lot but definitely not the bogging down weight. It still feels like some sort of memory leak but at least my computer is now usable again until an update is available. Hope this helps some of you.

Yeah glad I found this thread, I have the same problem. When using headphones and the computer goes to sleep, when it comes out, no audio until restart. I just checked activity monitor for Kernel_Task, and it's over 100% for CPU. No wonder my battery life is dropping like crazy... anybody call AppleCare yet?

I'm here to CONFIRM this bug, its very easily recreated by keeping the headphones connected -> Sleep -> wait for 1 minute -> Resume from Sleep = 100% Kernel_task CPU usage.

Its just about time after all these posts that Apple takes a corrective measures.

Is Apple Monitoring these discussion groups to start with? or we are just barking?

MacBook Air 13 2013 (Maxed) running Clean Install of OS X 10.9 (Not Upgraded from Mountain Lion)!

Looks like we're all experiencing the same issues.

Unfortunately for me, I can't reproduce it all of the time. For example, I was attempting to work last night and my computer experienced this bug and what should have taken 10 minutes turned into 2 hours because of the kernal_task. Then I had it running what I needed to all night, woke my machine up this morning to do another batch and kernal_task was down to a respectful 6%. Even when running my task, it stayed below 25%, like it should. Have no idea why as it was the exact same process. I just wish I could continuously reproduce it like you so that I could just disconnect the headphones to solve the problem temporarily.

Frankly, the only constant that brings up this bug is when i have my Thunderbolt display connected. Which I need. Plus, I never experienced this the first two weeks I upgraded to Mavericks.

Irregardless, Apple, please fix this bug!

I doubt that Apple is following this specific thread. So, please file a bug report at https://bugreport.apple.com if you are seeing this issue. The more that do so, the higher priority it will be to fix.

Apple Care doesnt do crap. I have collected logs for 2w now, nothing happens. My problem has nothing to do with headphones since it occurs all the time and I hardly ever use headphones. I had my MBP running all one and a half day maxing out kernel_task with nothing specific running (36h CPU time on 36h of uptime). I could have fried eggs on the lid and sent logs to Apple.