Questions tagged [kernel]

The core part of an operating system, responsible for managing resource allocation.

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votes
3answers
11k views

What is a Kernel Panic and what does it mean?

I have this report: Anonymous UUID: Removed Tue Aug 11 20:26:13 2015 *** Panic Report *** panic(cpu 2 caller 0xffffff8028bc1cde): "launchd died\nState at Last Exception:\n\n"@/SourceCache/xnu/...
130
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2answers
180k views

How to investigate high kernel task memory usage?

I was using my MBP (with 16GB of RAM) as usual and out of blue I've this popup that: Your system has run out of application memory. To avoid problems with your computer, quit any applications ...
19
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4answers
11k views

Which command controls the open file limits?

Which command / configuration file controls the open file limits on OS X? Is there a different command for OS X 10.5 / 10.6 / 10.7? The options I explore below are ulimit, sysctl, and launchctl "...
29
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6answers
63k views

How to disable the SpeedStep when using MacBook Pro without a battery?

First of all, the specs: MacBook Pro (15-inch, Early 2011) OS X 10.9.1 (Mavericks) 2.3 GHz Intel Core i7 8 GB RAM The Problem Recently, my battery randomly died and I had to disconnect it, ...
30
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3answers
56k views

What exactly does kernel_task do?

I'd just like to know what it is that kernel_task is responsible for. Also, what's an acceptable maximum RAM and CPU use for it?
21
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2answers
11k views

Insanely high kernel RAM usage (over 9GB) in Mavericks

I upgraded to Mavericks yesterday, and everything seemed to go fine, but today I noticed that my computer was becoming a bit slow. I checked Activity Monitor, and CPU / disk were at normal levels so I ...
4
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4answers
962 views

How to find cause of high kernel_task cpu usage?

Occasionally my machine will have a kernel_task instance max out the CPU: This can last from minutes to sometimes hours. The machine is effectively unusable in this state. Restarting doesn't help; a ...
11
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2answers
4k views

Is integrated VRAM included under `kernel_task` RAM in Activity Monitor?

I was stunned to discover that Mac OS X kernel can consume 750MB of RAM. A few related questions: Is it a problem if kernel_task is routinely above 130MB on mid 2007 white MacBook? kernel_task using ...
8
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3answers
7k views

How to properly increase a `ulimit -n` limits?

I'm trying to download the X-Plane 10 Demo through uTorrent, however I get a "too many open files" error all the time. I can do the alternate download (which takes forever and a day), but I wonder how ...
5
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2answers
1k views

Inspecting kernel_task

I have two MacBooks, one with a fresh OS X install and one with an older install. The older one has a kernel_task taking 1.52 GB of RAM. The newer one—416 MB. These aren't identical machines or ...
5
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1answer
1k views

How can I identify files and programs connected to the kernel_task process in Mac OS?

I understand that the kernel_task process is linked to several .kext files found in System/Library/Extensions (and possibly Library/Extensions ?) How can I identify which files are contributing to ...
9
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1answer
6k views

Why doesn't /proc exist in OS X?

What is the reason that /proc does not exist in OS X? I was curious to find file descriptors that a process was using in my Mac. The way I do it in linux is to go in /proc/fd folder of that process. ...
7
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2answers
6k views

How to disable logging to system.log in OS X?

During my time with Yosemite, I've had an innocuous issue that gets logged to system.log non-stop. This question is not about solving the issue. I'd like to stop the chatter, because they're writes ...
2
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6answers
5k views

My mac has 64-bit EFI, but it only boots with 32-bit kernel

I followed the guide at http://macperformanceguide.com/SnowLeopard-64bit.html to boot into 64-bit mode. I had no problems with the instructions and on the boot screen it says "PAE enabled, 64bit mode ...
1
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1answer
3k views

Mountain Lion Screen Freeze

My Mountain Lion is keeps freezing from few weeks, today it freezes/crashed couple of times already. Here is the log before the big freeze (file /var/log/system.log): SIMBL Enabler for Sandboxed ...
11
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2answers
3k views

Why does leaked memory appear malloced to kernel_task, and why can't OS X therefore garbage collect it

I have previously been told that a sign that some application has a memory leak is that kernel_task has a large memory footprint, commonly on the order of gigabytes. If an awry kext was causing this ...
4
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3answers
12k views

Why won't kern.maxfiles setting in /etc/sysctl.conf stick?

I've been getting various "too many files open in system"-type errors on Yosemite (10.10.1). Searching around suggests setting kern.maxfiles and kern.maxfilesperprocess in /etc/sysctl.conf. I've ...
9
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1answer
6k views

How to unload kernel modules

When I run kextstat, it gives me a list of the currently loaded kernel modules. How to I go about using the information gathered from this command to unload a kernel module?
6
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2answers
11k views

File location of kernel extensions?

Is there an easy way to make the mapping from kernel extension to the file it came from? I can get the list of currently loaded kernel extension via kextstat. This gives me the bundle names, like com....
6
votes
1answer
7k views

How do I increase “ulimit -u” (max user processes)?

I can change all of the usual ulimits via (for instance) ulimit -n 8192 and launchctl limit maxfiles 8192 8192. Somehow, this doesn't seem to work for -u, the maximum number of user processes: ~$ ...
4
votes
1answer
1k views

MacBook unusable due to kernel_task

I've disabled hibernation, and removed the sleep image file. I shutdown my Macbook Pro (15" retina), unticked the box to open windows on restart, and started my MacBook again. As soon as I'd logged on ...
8
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2answers
4k views

What's the maximum pid for Mac OS X?

The Mac OS X Internals book states that the maximum process identifier is 30,000 and after that the kernel will start re-using pids. But checking on my own system, via: ps a | grep ps | grep -v grep ...
7
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6answers
19k views

Very high kernel_task CPU usage after updating to Yosemite 10.10.4

I updated to 10.10.4 on July 1, and ever since I've had very high CPU usage - roughly 270%, i.e. two and a half of four processors - by kernel_task. It appears on login for about five minutes, then ...
3
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3answers
797 views

What does “Vector 0xdd(TMR)” do and how can I fix a problem that I'm having with it?

I am currently having problems with kernal_task using ~2GB of RAM and looking at what advice exists I ran sysdiagnose and in powermeterics.txt I found that Vector 0xdd(TMR) was doing ~20,000 ...
3
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1answer
116 views

Why do most processes run as children of launchd?

When did most processes run as a child of launchd instead of the kernel pid ?
3
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2answers
3k views

kernel_task is using 90% CPU, what could be the cause?

I have a 13" MBP late 2009, 2.53 GHz, 4 GB RAM, and on OS X 10.8.3. As soon as I boot up the fans start going at the highest rpm and like I mentioned the kernel_task is always at around 90% when no ...
2
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0answers
86 views

That Kernel Process Bloat

This is probably a question best suited for Apple Support Forums, but after asking variants of this question there to no avail, I will try here instead. I have a 2012/2013 2.3 GHz i7 Mac Mini w/ 16 ...
2
votes
1answer
8k views

Can't find kernel.log file on Yosemite

I began kernel programming on mac. Because I want to run my kernel extensions without code signing I had to do the following: sudo nvram boot-args=kext-dev-mode=1 It works as it should be, but the ...
1
vote
1answer
949 views

iOS: Where is /proc/?

Where is /proc/ in iOS? Or rather, why is it absent from the root directory structure? It's typically a crucial interface to the kernel of any UNIX-like operating system; what else is in place to ...
1
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2answers
1k views

Kernel_task boosts CPU to 300%-500% (Yosemitte MBP 2011 without a battery) [duplicate]

Long story short, my oldie MBP 2011' battery started bloating, I've contacted a repair service center and they advised me to remove the battery and use it on AC power, while they get a new battery for ...
0
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1answer
180 views

Kernel Tasks Swamping processor-2012 13" Retina

Acquired a 13" Retina liquid damaged - Apple Certified Tech. Trying to salvage. Haven't disassembled yet to see the extent of the liquid but it boots and runs. No liquid spill indicators triggered. ...