Limit CPU usage?

I notice there's an option to control how many threads Knime can run at once.. but my problem is that I like to multi-task, either within a Knime workflow or other apps.. but if I'm doing a Joiner on 1m rows, it tends to start hanging my system frequently.

How can I prevent Knime from ever using 100% of my CPU's 4 cores?  I wish there was a setting that simply said "Limit any thread to 90% of CPU"

This is not possible. The only thing you can do is to pin the process to certain processors. Or to reduce the scheduling priority. Both are operating system specific operation and usually requires root privileges.

How do I "pin the process to certain processors"?  If so I'll give it 3 of my 4 cores

On Linux you use the taskset command, on other OS I don't know. But I'm sure you will find answers with a quick internet search.