The first core of my i5 6600k cpu runs at nearly 100% all the time. To try and find the cause of this I am using perf as per this thread:

Kworker, what is it and why is it hogging so much CPU?

I ran "sudo perf report" which shows this:

click to see perf output

I do not understand the output but I think "kworker/0:1" and "[kernel.kallsyms]" have something to do with the problem. I looked at the perf wiki and perf man page but I cannot understand them.

I have some experience with Linux and am working on my new PC that I built. Would some one please help me understand the output of perf and help me use it to find the cause of my over loaded cpu core?

I will add that I am using Ubuntu 16.04 LTS


I took a guess at the output from perf and googled acpi from the Symbol thread. I looked at ubuntu's Debugging ACPI page, which said to first update my BIOS. Then I went to the ASRock site to update my BIOS (which is actually UEFI). Updating my Fatal1ty Z170 Gaming K4 motherboard seemes to fix the problem and the core is operating as the others. If the problem remains fixed for more than a day I will mark this as solved.

click to see normal CPU usage


The CPU has not misbehaved since the UEFI update. I am assuming that is what the problem was. Problem solved.

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