Linux Process Snapper (pSnapper, psn) is part of my open source 0x.tools suite of tools for Linux performance troubleshooting and always-on profiling of production systems.
pSnapper is a Linux /proc profiler that works by sampling Linux task states and other metrics from /proc/PID/task/TID pseudofiles. pSnapper is designed to be a low-tech passive profiler, it does not attach to your program to slow it down, nor alter your program execution path or signal handling (like strace may inadvertently do).
As pSnapper is just a python script reading /proc files, it does not require software installation, nor install any kernel modules. pSnapper does not even require root access in most cases. The exception is if you want to sample some “private” /proc files (like syscall, and kernel stack) of processes running under other users.
The current release v0.15 is a beta right now. I have many more features to add, some known issues to fix and the output & command line options may change.