This is a note to let you know that I've just added the patch titled selftests/ftrace: fix event-no-pid on 1-core machine to the 5.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-ftrace-fix-event-no-pid-on-1-core-machine.patch and it can be found in the queue-5.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0f8587935c63e29e731c4107ee13183711516875 Author: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx> Date: Wed Jun 23 15:43:15 2021 +0200 selftests/ftrace: fix event-no-pid on 1-core machine [ Upstream commit 07b60713b57a8f952d029a2b6849d003d9c16108 ] When running event-no-pid test on small machines (e.g. cloud 1-core instance), other events might not happen: + cat trace + cnt=0 + [ 0 -eq 0 ] + fail No other events were recorded [15] event tracing - restricts events based on pid notrace filtering [FAIL] Schedule a simple sleep task to be sure that some other process events get recorded. Fixes: ebed9628f5c2 ("selftests/ftrace: Add test to test new set_event_notrace_pid file") Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx> Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc index e6eb78f0b954..9933ed24f901 100644 --- a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc +++ b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc @@ -57,6 +57,10 @@ enable_events() { echo 1 > tracing_on } +other_task() { + sleep .001 || usleep 1 || sleep 1 +} + echo 0 > options/event-fork do_reset @@ -94,6 +98,9 @@ child=$! echo "child = $child" wait $child +# Be sure some other events will happen for small systems (e.g. 1 core) +other_task + echo 0 > tracing_on cnt=`count_pid $mypid`