[PATCH v3 0/3] kunit: allow running test suites/cases individually

[Daniel Latypov]

Allow running each suite or each test case alone per kernel boot.
The motivation for this is to debug "test hermeticity" issues.
This new --run_isolated flag would be a good first step to try and
narrow down root causes.

Context: sometimes tests pass/fail depending on what ran before them.
Memory corruption errors in particular might only cause noticeable
issues later on. But you can also have the opposite, where "fixing" one
test causes another to start failing.

Usage:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit --run_isolated=suite
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit --run_isolated=test
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit --run_isolated=test example

The last one would provide output like
  ======== [PASSED] example ========
  [PASSED] example_simple_test
  ============================================================
  Testing complete. 1 tests run. 0 failed. 0 crashed. 0 skipped.
  Starting KUnit Kernel (2/3)...
  ============================================================
  ======== [SKIPPED] example ========
  [SKIPPED] example_skip_test # SKIP this test should be skipped
  ============================================================
  Testing complete. 1 tests run. 0 failed. 0 crashed. 1 skipped.
  Starting KUnit Kernel (3/3)...
  ============================================================
  ======== [SKIPPED] example ========
  [SKIPPED] example_mark_skipped_test # SKIP this test should be skipped
  ============================================================
  Testing complete. 1 tests run. 0 failed. 0 crashed. 1 skipped.

See the last patch's description for a bit more detail.

Meta:
The first patch is from another series with just a reworded commit
message, https://lore.kernel.org/linux-kselftest/20210805235145.2528054-2-dlatypov@xxxxxxxxxx/

This patch series is based on Shuah's kunit branch:
https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/?h=kunit

Changes:
v1 -> v2: rebase onto Shuah's kunit branch, fix missing code in patch 1.
v2 -> v3: fix mypy errors, drop test plan from output, fix pre-existing
bug where kunit was not actually tracking test execution time (new patch 3).

Daniel Latypov (4):
  kunit: add 'kunit.action' param to allow listing out tests
  kunit: tool: factor exec + parse steps into a function
  kunit: tool: actually track how long it took to run tests
  kunit: tool: support running each suite/test separately

 lib/kunit/executor.c                   |  45 ++++++++-
 tools/testing/kunit/kunit.py           | 129 +++++++++++++++++--------
 tools/testing/kunit/kunit_tool_test.py |  40 ++++++++
 3 files changed, 169 insertions(+), 45 deletions(-)


base-commit: 3b29021ddd10cfb6b2565c623595bd3b02036f33
-- 
2.33.0.685.g46640cef36-goog