[PATCH 0/5] selftests/damon: misc fixes for test bugs

From: Kunwu Chan

Date: Sun May 31 2026 - 04:57:47 EST


From: Kunwu Chan <kunwu.chan@xxxxxxxxx>

This series fixes several bugs in the DAMON selftests. Most are
trivial but cause tests to silently pass when they shouldn't, or
fail prematurely on slow machines.

Patch 1 fixes mutable default arguments in DamonCtx.__init__()
that cause state to leak between test instances.

Patch 2 fixes a trailing comma in DamosFilter that turns
memcg_path from a string into a tuple, silently breaking memcg
filter setup.

Patch 3-4 fix bugs in damos_tried_regions.py: wrong operator
precedence drops the "not met" prefix from failure output, and
empty early aggregation cycles cause premature test failure.

Patch 5 fixes several wrong strings that produce dead elif
branches, skipped file existence checks, and broken dict key
lookups.

Based on next-20260529.
base-commit: 7da7f07112610a520567421dd2ffcb51beaefbcc

Kunwu Chan (5):
selftests/damon: prevent cross-context state pollution in DamonCtx
selftests/damon: fix memcg filter path handling
selftests/damon/damos_tried_regions: fix expectation output and join
TypeError
selftests/damon/damos_tried_regions: handle empty tried regions in
early cycles
selftests/damon: fix dead code, skipped checks, and broken lookups

tools/testing/selftests/damon/_damon_sysfs.py | 14 +++++++++----
.../selftests/damon/damos_apply_interval.py | 2 +-
.../selftests/damon/damos_quota_goal.py | 2 +-
.../selftests/damon/damos_tried_regions.py | 20 ++++++++++---------
.../selftests/damon/drgn_dump_damon_status.py | 2 +-
tools/testing/selftests/damon/sysfs.py | 4 ++--
tools/testing/selftests/damon/sysfs.sh | 6 +++---
...te_schemes_tried_regions_wss_estimation.py | 2 +-
8 files changed, 30 insertions(+), 22 deletions(-)

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2.43.0