Adding targeted testing for merge requests

Targeted testing is the term used to refer to CKI tests that are configured to run only for merge requests that affect specific subsystems or kernel source files.

Adding targeted testing per subsystem

1. Determine the GitLab merge request label for the subsystem from the owners.yaml file, or by looking at suitable merge requests.

2. Determine whether the test you want to run is already onboarded to kpet-db. If not, talk to your friendly QE counterpart to add the test.

3. File a merge request in kpet-db to enable the test for the subsystem in the respective test case in cases/.

   • To trigger the test for changes to any file that belongs to the subsystem, add the subsystem label prefixed with @ to the target_sources key like

     target_sources:
       - @mm
     

   • To trigger the test for subsystem files matching a certain pattern, append a regular expression to the subsystem label like

     target_sources:
       - @mm/.*\.[ch]
     

   • To trigger the test for a specific subsystem file, append the file name to the subsystem label like

     target_sources:
       - @mm/mm/page_counter\.c
     

   The test maintainer as specified in the test case is the best person to help you out if you have troubles getting things to work and for reviewing your merge request.

Adding targeted testing per kernel source file

Configuration

The configuration is done in the test case in kpet-db. In case some files should trigger the test, but not be considered for targeted testing the file should be added under trigger_sources list.

Example: block tests

...
target_sources:
- block/blk-cgroup\.c
- block/blk-mq-debugfs\.c
- block/elevator\.c
- block/blk-mq-sched\.c
- block/blk-mq\.c
- block/blk-mq-sysfs\.c
- block/cfq-iosched\.c
- block/kyber-iosched\.c
- block/bfq-iosched\.c
- block/blk-core\.c
- block/mq-deadline\.c
trigger_sources:
- block/.*
...

Missing targeted tests

Merge requests that have missing targeted tests have the ‘TargetedTestingMissing’ label.

What that means?

It means that at least 1 file updated by the merge request doesn’t have a specific test that covers it.

What file(s)?

The list of files missing targeted tests are in the setup jobs in the pipelines (doesn’t matter the architecture they contain the same information).

Example:

Some source files are not targeted by any tests:
fs/userfaultfd.c
include/uapi/linux/userfaultfd.h

What to do?

1. Looking at CKI tests, maybe some test could be configured to run on that file. It can be confirmed by running the test using code coverage.

2. Write/onboard new test case for it.

3. Talk with QE that covers this area to write/onboard new test case for it.

Don’t hesitate to contact CKI team for help.