Learn what function the kernel_task Mac process performs, what may cause it to act up, and what to do if this entity is using up way too much CPU.
Macs are neither flawless in terms of performance nor are they immaculate in regards to security. But, they are still architected remarkably to tackle both of the above pitfalls with a fair degree of efficiency, which is incidentally one of the main reasons why becoming an Apple customer is on so many people’s wish list. While boasting a software design that isn’t likely to make users frown on its stability, Mac computers – both desktop and laptops – are susceptible to problems that seem marginal at first sight but actually create ripples among people who are at their wit’s end seeking to find a fix. This is the case with the kernel_task process that may malfunction in a really peculiar way. Specifically, it might cause a Mac’s CPU to skyrocket, thereby ostensibly making the computer slow and irresponsive.
Let’s dot some i’s and cross a few t’s before we proceed. Kernel_task isn’t a malicious entity or anything – it’s a service built into macOS. Moreover, it performs an important job of managing the heat of the central processing unit. In particular, it is launched when the system receives signals about certain programs and processes consuming the CPU power in anomalous amounts. When running, kernel_task tries to restrict memory allocation to these “hungry” apps. Once the temperature gets back to normal, this process is supposed to get idle and stay that way until the same disconcerting conditions reappear. However, the gray facet of this workflow is that the benign service in question may start using close to all CPU resources, or even worse, the percentage reflected in Activity Monitor can exceed 100%, no matter how weird this may appear.
Such an intense consumption of a machine’s memory capacity, obviously, has a significant system footprint. The Mac slows down to a crawl, and the fan will keep spinning at its maximum for hours, which is likely to have an adverse effect upon the machine’s health altogether. Now, when behavior like this is being exhibited by an arbitrary application, the easiest fix is to go to Activity Monitor and quit the troublemaking process. In the case of kernel_task, though, this is a no-go because it’s a native macOS or Mac OS X routine that cannot be stopped in this manner. Most of the time, a computer restart addresses the problem, but the result typically doesn’t last and the problem resurfaces shortly.
Speaking of the reasons for excessive CPU usage by the object under scrutiny, there can be a few. One is related to out-of-date Adobe Flash Player. If so, the solution is to either update the suite or disable it completely – in the latter case, there may be hurdles with viewing certain online content. Another cause for these issues boils down to the activity of corrupt kernel extensions, also referred to as “kexts”. Whereas these are normally harmless system-critical items mostly added by Apple, some of them may be third-party extensions routinely installed as hardware drivers or something similarly auxiliary. If misconfigured, these objects may take up lots of CPU and thus trigger a response in the form of kernel_task trying to sort things out.
Finally, a factor underestimated by many users has to do malware. If a cryptominer ends up on a Mac computer and if it doesn’t utilize any throttling practices, it will start exploiting all of the processing unit’s available resources. This intrusion, in its turn, makes the operating system act accordingly. In fact, there can be more types of harmful code that make kernel_task react in its very own way, including scareware, adware, and aggressive browser add-ons. One way or another, it makes sense to ascertain that there is no virus component in this scenario. Follow the tips below to find and fix all the possible reasons for misbehavior of the process that makes a Mac run hotter than it should.
Manual removal of malware causing kernel_task high CPU usage
The steps listed below will walk you through the removal of the potentially unwanted application. Be sure to follow the instructions in the order specified.
- Open up the Utilities folder as shown below
- Locate the Activity Monitor icon on the screen and double-click on it
- Under Activity Monitor, find a suspicious entry that shouldn’t be there (e.g. Mac Cleanup Pro or MacKeeper), select it and click Quit Process
- A dialog should pop up, asking if you are sure you would like to quit the potentially harmful executable. Select the Force Quit option
- Expand the Go menu in Apple Finder and select Applications on the list. Find the entry for the likely culprit on the interface, right-click on it and select Move to Trash. If user password is required, go ahead and enter it
- Now go to Apple Menu and pick the System Preferences option
- Select Accounts and click the Login Items button. The system will come up with the list of the items that launch when the box is started up. Locate the unwanted applications there and click on the "-" button
Get rid of malicious add-ons in web browser on Mac
To begin with, settings for the web browser that got hit by the troublemaking extension should be restored to their default values. The overview of steps for this procedure is as follows:
- Reset Safari
- Open the browser and go to Safari menu. Select Preferences in the drop-down list
- Once the Preferences screen appears, hit the Privacy tab at the top. Find the option that says Remove All Website Data and click on it
- The system will display a confirmation dialog that also includes a brief description of what the reset does. Specifically, you may be logged out of some services and encounter other changes of website behavior after the procedure. If you’re okay with that, go ahead and click the Remove Now button
- In order to selectively clear data generated by certain websites only, not all of them, hit the Details button under the Privacy section of Safari Preferences
- This feature will list all websites that have stored potentially sensitive data, including cache and cookies. Select the one, or ones, that might be causing trouble and click the appropriate button at the bottom (Remove or Remove All). Click the Done button to exit.
- Open the browser and go to Safari menu. Select Preferences in the drop-down list
- Reset Google Chrome
- Open Chrome, click the More (⁝) icon in the top right-hand part of the window, and select Settings in the drop-down
- When on the Settings pane, select Advanced
- Scroll down to the Reset settings section. Under the Restore settings to their original defaults option, click the Reset settings button
- Confirm the Chrome reset on a dialog that will pop up. When the procedure is completed, relaunch the browser and check it for malware activity.
- Reset Mozilla Firefox
- Open Firefox and select Help – Troubleshooting Information
- On the page that opened, click the Reset Firefox button
Use automatic tool to fix the kernel_task Mac issue
The Mac maintenance and security app called Combo Cleaner is a one-stop tool to detect and remove Mac viruses and fix performance issues. This technique has substantial benefits over manual cleanup, because the utility gets hourly virus definition updates and can accurately spot even the newest Mac infections.
On top of that, the automatic solution will find the core files of the malware deep down the system structure, which might otherwise be a challenge to locate. Here’s a walkthrough to sort out the kernel_task issue using Combo Cleaner:
- Download Combo Cleaner installer. When done, double-click the combocleaner.dmg file and follow the prompts to install the tool onto your Mac.
- Open the app and let it run the update of malware signature database to make sure it can identify the latest threats.
- Click the Start Combo Scan button to check your Mac for malicious activity as well as performance issues.
- When the scan is complete and Combo Cleaner returns the results, click the Remove Selected Items button and have the utility remove the malware that causes high CPU usage by kernel_task, along with any other viruses, PUPs (potentially unwanted programs), or junk files that don’t belong on your Mac.