Re: [RFC PATCH 1/1] kselftests: Add test to detect boot event slowdowns

From: Shuah Khan
Date: Thu Jul 25 2024 - 11:50:50 EST


On 7/25/24 05:06, Laura Nao wrote:
Introduce a new kselftest to identify slowdowns in key boot events.
The test uses ftrace to track timings for specific boot events.
The kprobe_timestamps_to_yaml.py script can be run once to generate a
YAML file with the initial reference timestamps for these events.
The test_boot_time.py script can then be run on subsequent boots to
compare current timings against the reference values and check for
significant slowdowns over time.
The test ships with a bootconfig file for ftrace setup and a config
fragment for the necessary kernel configurations.

Signed-off-by: Laura Nao <laura.nao@xxxxxxxxxxxxx>

I am repeating the same comments I made on the cover letter here as
well.

What are the dependencies if any for this new test to work?
Please do remember that tests in default run needs to have
minimal dependencies so they can run on systems that have
minimal support.

As mentioned earlier take a look at the tools/power/pm-graph
bootgraph.py and sleepgraph.py to see if you can leverage
them - bootgraph detects slowdowns during boot.

We don't want to add duplicate scripts if the other one
serves the needs. Those can be moved to selftests if it
make sense.

I will review this once we figure out if bootgraph serves
the needs and I understand the dependencies for this test
to work.

thanks,
-- Shuah