Post Syndicated from original https://lwn.net/Articles/889607/

The ftrace and perf subsystems provide visibility into the workings of the
kernel; by activating existing tracepoints, interested developers can see
what is happening at specific points in the code. As much as kernel
developers may resist the notion, though, not all events of interest on a
system happen within the kernel. Administrators will often want to look
inside user-space processes as well; they would be even happier with a
mechanism that allows the simultaneous tracing of events in both the kernel
and user space. The user-events
subsystem, developed by Beau Belgrave and added
during the 5.18 merge window,
promises that capability, but users will almost certainly have to wait
another cycle to gain access to it.