Post Syndicated from Lennart Poettering original https://0pointer.net/blog/projects/name-your-threads.html

Stefan Kost recently pointed me to the fact that the Linux system call
prctl(PR_SET_NAME) does not in fact change the process name, but the
task name (comm field) — in contrast to what the
man page suggests.

That makes it very useful for naming threads, since you can read back the
name you set with PR_SET_NAME earlier from the /proc file system
(/proc/$PID/task/$TID/comm on newer kernels,
/proc/$PID/task/$TID/stat‘s second field on older kernels), and hence
distuingish which thread might be responsible for the high CPU load or similar
problems.

So, now go, if you have a project which involves a lot of threads, name them
all individually, and make it easier to debug them. What’s missing now, of
course, is that gdb learns this and shows the comm name when doing info
threads.

I have changed PulseAudio now to name all threads it creates.

Of course, what would be even better than this is full file system extended
attribute support in procfs, so that we could attach arbitrary information to
processes and threads, including references to .desktop files and such.