sysctl kernel.ftrace_enabled=1
#echo 0 >tracing_on; sleep 1; echo 1 >tracing_on; sleep 20; echo 0 >tracing_on;sleep 1; cat trace >/tmp/123.txt
bash -c "echo 1 >$TRACEDIR/tracing_on"
sysctl kernel.ftrace_enabled=1
#echo 0 >tracing_on; sleep 1; echo 1 >tracing_on; sleep 20; echo 0 >tracing_on;sleep 1; cat trace >/tmp/123.txt
bash -c "echo 1 >$TRACEDIR/tracing_on"