How can I monitor the thread count of a process on linux?

Question

I would like to monitor the number of threads used by a specific process on Linux. Is there an easy way to get this information without impacting the performance of the proc

Answer 1

To get the number of threads for a given pid:

$ ps -o nlwp 

Where nlwp stands for Number of Light Weight Processes (threads). Thus ps aliases nlwp to thcount, which means that

$ ps -o thcount 

does also work.

If you want to monitor the thread count, simply use watch:

$ watch ps -o thcount 

To get the sum of all threads running in the system:

$ ps -eo nlwp | tail -n +2 | awk '{ num_threads += $1 } END { print num_threads }'