/sys/kernel/debug/tracing/trace_marker Bad file descriptor error

Question

Im trying to do

echo "FINN" > /sys/kernel/debug/tracing/trace_marker

inside the shell (ubuntu 14) as root and im getting the next error

bash: echo: write error: Bad file descriptor

I dont know what is wrong, I read how to do it here and here (articles about how using ftrace)

Other ftrace files that I had to write into worked fine...

Answer 1

You might have run

echo 0 to tracing_on

You can run

echo 1 > tracing_on

and

echo something > trace_marker

and it should work again.