[J][SRU][PATCH 0/1] selftests/ftrace: Stop tracing while reading the trace file by default

[Po-Hsu Lin]

BugLink: https://bugs.launchpad.net/bugs/2029405

[Impact]
On ARM64 systems, tests like subsystem-enable.tc, event-enable.tc,
event-pid.tc in linux/tools/testing/selftests/ftrace will take too
much time to run and consequently leads to test timeout.

The culprit is the `cat` command on the changing trace file.

[Fix]
* 25b9513872 selftests/ftrace: Stop tracing while reading the trace
  file by default

This patch can be cherry-picked into Jammy. I didn't see this issue in
our 5.4 kernels. And it's already landed in newer kernels.

[Test]
On an ARM64 testing node, apply this patch to the kernel tree and run
event-pid.tc test in linux/tools/testing/selftests/ftrace with:

  sudo ./ftracetest -vvv test.d/event/event-pid.tc

The test should finish within a few minutes.

[Regression Potential]
Change limited to testing tools, it should not have any actual impact
to kernel functions.


Masami Hiramatsu (1):
  selftests/ftrace: Stop tracing while reading the trace file by default

 tools/testing/selftests/ftrace/ftracetest       |  2 +-
 tools/testing/selftests/ftrace/test.d/functions | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

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2.7.4