
OS X Mavericks kernel_task eating 100% CPU - EpicEng
https://discussions.apple.com/thread/5497235?start=0&tstart=0
======
code_duck
I had a strange problem appear after I spilled tea on my 2010 MBP last year.
Continually, kernel_task was using an entire core (150-250% in top) and no
amount of reboots could fix this. The built-in hardware diagnostic indicated
it was not compatible with my Mac, and I could find nothing else that
apparently was wrong. My computer was running very slowly though, and the
system load was always over 4.

Finally I found through research that this is somehow related to power
management. Apparently the system will have the CPU loop simple operations to
prevent the processor from doing actual work and heating up. Sure enough,
disabling power management by hacking a kernel extension made the kernel_task
problem go away. My Mac has run perfectly for three months ever since I made
that fix, after being nearly disabled for a year.

~~~
cliveowen
Damn, my 2009 Macbook has been running _very_ slowly for the past 4 months or
so and no amount of rebooting would resolve the problem. I was actually
puzzled when it slowed down to a crawl becoming basically useless and would
even restart with the same slowness. Could you elaborate on your fix?

~~~
btown
See my comment above - it might help.

~~~
cliveowen
Thank you.

------
VeejayRampay
Any other company that would DARE completely ignore the cries for help of its
consumers would be publicly shamed and their reputation would suffer.

Yet, not a single word in this thread about how silent they tend to be about
issues effecting thousands of users (which is a common trend with them)...

I wonder how they manage to pull that off, it's magic.

~~~
sitharus
Really? Name one non open-source company that will jump on forum threads and
fix it, rather than just putting it in their internal bug tracker to
investigate.

I have a Logitech gaming keyboard. Their drivers are shockingly bad and freeze
up every so often requiring me to re-plug the keyboard to get them to to work
again. This is mentioned in the forums for at least 6 months, no fix has been
announced.

I'm not defending Apple here, they should at least comment on their own
forums, but they're not alone.

~~~
larrys
Back in the day, when there was no internet (only the arpanet) and Unix
systems shipped with 10 manuals in nicely bound cases (I had one I was in my
20's at the time) things moved much slower and a vendor would never consider
acting like this because they served primarily business customers (and
institutions). Just the memory on my first Unix system was like $4000 a MB. It
came with a 70mb hard disk.

To me the change most likely came around 1981 when the IBM PC came out and was
sold to consumers who basically believed that it was them that was stupid and
not something wrong with the machine. Manufacturers then learned that they
could shove things into the pipeline and fix them later and that they actually
got a fair amount of slack in the marketplace from the "stupid" end users.
People who knew their shit using these machines were totally outnumbered by
computer illiterate people. In other cases the ubiquitous "tech guy" made
money because things didn't work so who was he to complain? That's what kept
Microsoft in power. The tech guy ecosystem.

I'm curious if anyone else agrees at all with my take. Strictly my opinion
having been around computers so many years.

~~~
sitharus
It really depends on the number of customers.

If you have 1 million $10 customers and 10,000 have a problem the cost of
losing their business isn't amazingly huge, especially as most of them
probably won't switch vendors.

When you have ten $1,000,000 customers you might listen more if one has a
problem.

------
yellowbkpk
This, along with my wifi connection dying every hour or two (requiring a
restart) makes me wish I had never upgraded to Mavericks.

Link to wifi discussion:
[https://discussions.apple.com/thread/5535320](https://discussions.apple.com/thread/5535320)

~~~
Auguste
I've had this problem with all my Macs at home, although it would never occur
with other Wi-Fi access points. This leads me to believe it has something to
do with the wireless access point itself.

I was never able to fix the problem, but it went away after I bought an
AirPort Time Capsule, which now serves as my wireless router. It has an
extremely limited feature set compared to a real router, but I haven't had
connection problems once since implementing it.

~~~
yellowbkpk
Do you use a bluetooth keyboard? My wifi flakiness seems to be much less of a
problem when my lid is open and I'm typing on the builtin keyboard than when
the lid is closed and I'm using the Apple bluetooth keyboard.

It's so intermittent that it's very hard to diagnose, but that's one thing
I've noticed.

~~~
Auguste
No, I don't have a bluetooth keyboard. On the Macbooks I use the built-in. On
the iMac I use a wired keyboard.

------
tokanizar
In my opinion, Mavericks is the worst OS X version so far. It's caused a
handful of crashes/hangs to my Macbook Pro, which I only encountered with
about once or twice a year with Snow Leopard, Lion and Mountain Lion. I'm not
sure it is caused by the OS itself or the compatibility of the apps I
installed, but it's still bad.

I just had a crash few mins ago after I reinstalled the OS entirely last week.
According to the crash log, it has something to do with the "kernel_task".
That sucks!

~~~
DrJokepu
> Mavericks is the worst OS X version so far

You have clearly never used Cheetah.

~~~
mitchty
As someone thats been on the osx train since 10.2. I get somewhat amused by
the "OSX N+latest is the worst OSX" comments.

I had the (dis)pleasure of using someone's 10.1 machine, oy wow, surprised
that even got released.

As a counterpart, mavericks has been the most stable osx for myself so far.
Additionally the battery life improvements gave me an extra hour on battery
alone. You can pry mavericks from my cold dead hands at this point. The energy
tab is also really useful at finding out what is using up battery needlessly
(looking at you chrome/firefox).

~~~
tokanizar
I feel jealous with your luck. I've had as many crash as I can imagine since
switching to Mac from Windows (before, I don't even remember how many times I
got freezing apps or BSOD). And it seems to occur that _often_ since Mavericks
so it's my sole assumption.

I agree about the battery life improvements part as a nomadic user. However,
it's totally depends on which applications you are using. For me,
chrome/firefox, which eats up most of the battery, is used constantly,
therefore, cannot be turned off (to save energy, because it doesn't support
AppNap, I suppose). I don't see any help looking at the Energy Tab as whatever
it's like, I don't have a choice there.

------
alimoeeny
Problems I have, on a brand new 15 retina MBPro: 1- after wake from sleep,
wifi needs to be turned off and on to find anything

2- no sound from internal or external speaker until restart, although the OS
behaves as nothing is wrong, the onscreen indicators and system preferences
act as if they are muting and unmuting and changing the volume

3- kernel panics every now and then

4- display jitters (like graphic buffer corruption) a couple of times

5- after wake up from sleep , keyboard does not respond while track pad is,
which means I cannot login, needs force shutdown,

~~~
pudquick
"on a brand new 15 retina MBPro"

You have a warranty. Use it.

Complaints here do not solve your problems.

If Apple cannot solve your problems, within the terms if your warranty, they
will offer alternatives (eventually) - up to and including a refund.

I understand people want to raise issues to "public awareness" that they feel
are something Apple should pay attention to. And in the case of the original
submission, VERY SPECIFIC details were figured out - and Bug Reported to
Apple! Apple even closed some of the reports as a duplicate. They know about
this problem - and it's for a new OS that has only been out for a handful of
months - and the issue is for specific hardware builds.

They are working on it.

You, however, have a laundry list of real issues - USE YOUR WARRANTY.

~~~
coldtea
Some of those (minor) problems, in fact most, are the standard kind of "new
OS" bugs. None of them sounds like its about hardware faults. So your advice
is not really applicable here. He'd better wait for 10.9.2 and such.

~~~
pudquick
My advice is 100% applicable. Especially with issue #5, but in general as
well.

You don't seem to understand: He is unhappy with what he purchased because he
is experiencing problems that should not exist in the product. A brand new
product. And not just a single issue - but several of them!

This isn't a device that (in his personal experience) worked fine at some
point in the past on a different version of software but now is having
problems on the latest software update.

This is a device that, brand new from Apple, has problems. This point is
especially relevant as you cannot downgrade a Mac from Apple to an OS version
that came out prior to the introduction of that specific model of machine. The
Late 2013 MacBook Pro Retina devices shipped with Mavericks. They will _never_
run Mountain Lion, you cannot avoid Mavericks on them for the time being.

This is the entire point of a warranty (and lemon laws in many locations): You
don't have to "wait" for something you just bought to get better / work
properly.

You take it back and show them the problems you're having.

Either they can fix it or they can't. If they can't fix it, he can get his
money back or some other alternative offered by Apple that he might agree to
(maybe a different model, or a complete replacement).

His money is not trapped in this device, so he doesn't have to put up with
this experience - unless he actually _prefers_ to complain and be unhappy.

~~~
coldtea
> _You don 't seem to understand: He is unhappy with what he purchased because
> he is experiencing problems that should not exist in the product. A brand
> new product. And not just a single issue - but several of them!_

Which product came with a brand new OS version. And which, like most OS
launches has several software issues. Which are not gonna be solved if he
returns his device (or only randomly, if they affect just one of a few Apple
OEM partners chipsets etc).

> _This is the entire point of a warranty (and lemon laws in many locations):
> You don 't have to "wait" for something you just bought to get better / work
> properly._

That only holds if it's a faulty device. For OS and driver bugs, you very much
have to wait. And no matter how long you wait, there will always be some bugs
to, err, bug you, in it.

------
shurcooL
I've had no problems with my MBP for the last 2+ years. Happy user here.

~~~
elwell
No overheating?

~~~
shurcooL
Nope, it gets as hot/noisy as I feel is appropriate for the amount of work
it's doing.

------
rjzzleep
guys there's a fix. i have a 2013 mba. the problem is in applehda. you can
look at the hpet shoot up after sleep using `powermetrics`

here's a video to reproduce the issue

[http://youtu.be/Q8OqdMq98j4](http://youtu.be/Q8OqdMq98j4)

and here's a dmg that has the fix. basically it replaces applehda with the one
from 10.8.5

[http://puu.sh/5RBvj.dmg](http://puu.sh/5RBvj.dmg)

i've been using it happily for ten days. some people claimed it wouldn't work
with haswell, but it does for me. YMMV though

~~~
muhaha03
it doesn't work for rmbp 2013 late.

~~~
rjzzleep
i think the latest mbp's might have a different product id on the intel hda.
does your sound disappear with the old driver?

~~~
muhaha03
yep. but it solved the kernel 100% problem.

------
majke
Workaround:

\- First. stop playing music (in your browser, itunes or whatever).

\- Next wait 5 minutes

\- Last, close lid (go to sleep) and open again again.

Works for me.

My biggest problem is that my mac freezes once a day.

~~~
EpicEng
Closing the lid (sleeping) is what is causing it for many people (myself
included). I just have to leave it open or reboot.

~~~
NoPiece
My Mac freezes a few times a week. Just the window manager, because I can
still ssh in. I know it isn't the lid, because it is an iMac, but it may be
going to sleep that kills it.

------
dhughes
Another (much more) common issue which seems to be related to Mavericks is the
Finder problem where clicking Finder results a sudden hang of the system a the
spinning colour wheel.

I'm fairly new to Apple products (~2 years ago) this is the worst problem so
far but I'm surprised at such little feedback from Apple on it.

~~~
jasomill
Not Mavericks-specific, but Finder is notorious for hanging when mounted
volumes become unavailable or unreliable. And it's certainly possible that
some of the network filesystem changes in Mavericks — in particular, it now
uses SMB in certain cases where previous versions would have defaulted to AFP
— could lead to this behavior in situations where you didn't see it before.

------
wxm
Solution on a late 2013 MBP for me (when the issue occurs no sound is playing
anymore - no system sounds, no videos, no audio): Plugging in earphones and
unplugging. Killing the coreaudio process as recommended at a few places
online doesn't do the trick, unfortunately.

------
nemothekid
I've been wrestling this as well, and found this post too. Another problem I
frequently wrestle with is my air sleeping on not coming back (the keyboard
stays lit though). Only way to get it back is too reboot.

------
ics
I experienced this right out of the gate after upgrading. I was very curious
to see what my battery savings would be and decided to ditch my charger, only
to have my battery gone in an hour. It's since subsided– I'm not really sure
why, though at one point I did about everything I could think of short of
reinstalling. I removed all kernel extensions I had added (KR4MB for example),
removed SIMBL, reset PRAM, cycled the battery, etc. Now the only issue I have
is about 10s after closing the lid, the fan goes nuts for another 10s before
going to sleep.

Edit: Spring 2011 MacBook Pro.

------
toyg
My personal list of gripes (1st-gen 15" MBPr) is short, but it's sad that they
all appeared after the Mavericks upgrade:

1\. wifi will fail to reconnect on wake.

2\. almost 40% of RAM (about 6 GB of 16) in use _right after boot_ with no
apps running. Was about 15% before Mavericks.

3\. I got the dreadful Keychain error once, luckily managed to fix it (I use
FileVault, so no SafeBoot for me and losing the key would have been fairly
disastrous).

All these very clearly appeared after I took the plunge and moved to 10.9.1.
Somebody screwed up.

~~~
lukasm
Same problems. Have to plug and unplug headphones. to fix kernel_task

------
wickedlogic
It's related to the audio driver and is triggered most frequently when you
close the laptop with headphones in. Simply unplug them, close the laptop, and
wait for 5-10 seconds. reopen... you will still see the cpu spike, but it will
end within a few seconds of everything awaking... it is annoying, but this
seems to resolve it for now.

------
raverbashing
I gave up on Mavericks after it went on an irreparable rampage of asking me
for a "keychain password", then after trying a fix it just wouldn't boot
anymore.

It required me to recover using Time Machine (and had a lot of workarounds,
because it can't recover booting from the recovery partition in the HD, sigh)

~~~
pacomerh
I had the same issue with the keychain and repaired permissions on files to
fix the issue.

~~~
raverbashing
Yeah, this might have helped.

The solution I tried involved changing some files in /Library/Keychains, but
it didn't work

And the worse thing is that after that, a disk scan (using the Recovery boot)
showed some errors on the HD, but these were non-recoverable

~~~
andrewfree
If you boot into recovery drive and go under Utilities -> Terminal type
'resetpassword' and in that same window there will be a ACL ( OS X Access
Control Lists ) reset for an account. If you do that when you reboot, it
prompts you to make a new keychain before logging you in.

------
xjtian
I've been running into this problem with my 2013 MBA. It happens on wake, and
the only that fixes it is a reboot. I'm getting pretty fed up with the issue
since it's tanking my battery life and there seems like nothing I can do to
fix it permanently.

------
znep
Unrelated to this particular issue, but lately Adobe Updater has taken to
running lsof in a tight loop, waiting for me to exit Acrobat so it can update.
Makes for a pretty solid red bar of system CPU use.

------
nikanj
On mine, unplugging the external screen for a while fixes everything
[http://www.youtube.com/watch?v=_kppD1PotFw](http://www.youtube.com/watch?v=_kppD1PotFw)

------
bpicolo
That explains why my Mac has been crazy sluggish lately...

~~~
_delirium
Could also be other issues unless you see this specific set of symptoms. Mine
gets sluggish but it seems to have something to do with the 'systemstats'
process. When I open up something that queries it (e.g. click on the power
icon in the menu bar to make it go to "Collecting power usage information...",
or open Activity Monitor), it goes nuts, pegging the CPU and ballooning to
>2GB of memory. Haven't figured out what to do about that, besides kill -9'ing
it and avoiding doing anything that'll cause it to respawn.

~~~
_delirium
Reply to self, in case anyone comes across this:

Moving the /private/var/db/systemstats directory out of the way and rebooting
seems to have solved the problem. Guess something there was corrupt or too
large.

------
taterbase
One key thing that I've noticed consistently is this happens when I have my
headphones plugged in. Unplug them, put it back to sleep and wake it.

------
stevewillows
I had an issue with mavericks on an old early 2008 MBP - - mavericks nearly
cooked the computer on a fresh install.

------
kybernetyk
This bug appeared for me after the update to 10.9.1 (from 10.9) on my 2013
MBA.

------
broabprobe
yup, also have this bug. It remedies itself after a minute or two.

------
plg
Maybe you're holding it wrong. #antennagate

~~~
coldtea
Antennagate? You mean that old non-issue blown up by some media out of all
proportion, that happened to phones before and since (including competitors
phones), and despite which "issue" the iPhone 4 went on to sell further tens
of millions of devices with the same design?

No, I think unlike that, this is a real problem.

