On Sat, 20 Nov 2021 13:17:08 +0100
Marco Elver [off-list ref] wrote:

I think userspace would want something other than perf tool to handle it
of course.  There are several options:

	1. Open trace pipe to be notified (/sys/kernel/tracing/trace_pipe).
	   This already includes the pid.

I would suggest using /sys/kernel/tracing/per_cpu/cpu*/trace_pipe_raw

and use libtracefs[1] to read it.

-- Steve

[1] https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/