drgn_dump_damon_status.py is a script for dumping DAMON internal status in
json format. It is being used for seeing if DAMON parameters that are set
using _damon_sysfs.py are actually passed to DAMON in the kernel space.
It is, however, not dumping full DAMON internal status, and it makes
increasing test coverage difficult. Add damos filters dumping for more
tests.
Link: https://lkml.kernel.org/r/20250720171652.92309-12-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
drgn_dump_damon_status.py is a script for dumping DAMON internal status in
json format. It is being used for seeing if DAMON parameters that are set
using _damon_sysfs.py are actually passed to DAMON in the kernel space.
It is, however, not dumping full DAMON internal status, and it makes
increasing test coverage difficult. Add ctx->ops.id dumping for more
tests.
Link: https://lkml.kernel.org/r/20250720171652.92309-11-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
drgn_dump_damon_status.py is a script for dumping DAMON internal status in
json format. It is being used for seeing if DAMON parameters that are set
using _damon_sysfs.py are actually passed to DAMON in the kernel space.
It is, however, not dumping full DAMON internal status, and it makes
increasing test coverage difficult. Add damos->migrate_dests dumping for
more tests.
Link: https://lkml.kernel.org/r/20250720171652.92309-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/damon/sysfs.py: test all parameters".
sysfs.py tests if DAMON sysfs interface is passing the user-requested
parameters to DAMON as expected. But only the default (minimum)
parameters are being tested. This is partially because _damon_sysfs.py,
which is the library for making the parameter requests, is not supporting
the entire parameters. The internal DAMON status dump script
(drgn_dump_damon_status.py) is also not dumping entire parameters. Extend
the test coverage by updating parameters input and status dumping scripts
to support all parameters, and writing additional tests using those.
This increased test coverage actually found one real bug
(https://lore.kernel.org/20250719181932.72944-1-sj@kernel.org).
First seven patches (1-7) extend _damon_sysfs.py for all parameters setup.
The eight patch (8) fixes _damon_sysfs.py to use correct max nr_acceses
and age values for their type. Following three patches (9-11) extend
drgn_dump_damon_status.py to dump full DAMON parameters. Following nine
patches (12-20) refactor sysfs.py for general testing code reuse, and
extend it for full parameters check. Finally, two patches (21 and 22) add
test cases in sysfs.py for full parameters testing.
This patch (of 22):
_damon_sysfs.py contains code for test-purpose DAMON sysfs interface
control. Add support of DAMOS watermarks setup for more tests.
Link: https://lkml.kernel.org/r/20250720171652.92309-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250720171652.92309-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a python-written DAMON sysfs functionality selftest. It sets DAMON
parameters using Python module _damon_sysfs, reads updated kernel internal
DAMON status and parameters using a 'drgn' script, namely
drgn_dump_damon_status.py, and compare if the resulted DAMON internal
status is as expected. The test is very minimum at the moment.
Link: https://lkml.kernel.org/r/20250628160428.53115-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/damon: add python and drgn based DAMON sysfs
functionality tests".
DAMON sysfs interface is the bridge between the user space and the kernel
space for DAMON parameters. There is no good and simple test to see if
the parameters are set as expected. Existing DAMON selftests therefore
test end-to-end features. For example, damos_quota_goal.py runs a DAMOS
scheme with quota goal set against a test program running an artificial
access pattern, and see if the result is as expected. Such tests cover
only a few part of DAMON. Adding more tests is also complicated.
Finally, the reliability of the test itself on different systems is bad.
'drgn' is a tool that can extract kernel internal data structures like
DAMON parameters. Add a test that passes specific DAMON parameters via
DAMON sysfs reusing _damon_sysfs.py, extract resulting DAMON parameters
via 'drgn', and compare those. Note that this test is not adding
exhaustive tests of all DAMON parameters and input combinations but very
basic things. Advancing the test infrastructure and adding more tests are
future works.
This patch (of 6):
'drgn' is a useful tool for extracting kernel internal data structures
such as DAMON's parameter and running status. Add a 'drgn' script that
extracts such DAMON internal data at runtime, for using it as a tool for
seeing if a test input has made expected results in the kernel.
The script saves or prints out the DAMON internal data as a json file or
string. This is for making use of it not very depends on 'drgn'. If
'drgn' is not available on a test setup and we find alternative tools for
doing that, the json-based tests can be updated to use an alternative tool
in future.
Note that the script is tested with 'drgn v0.0.22'.
Link: https://lkml.kernel.org/r/20250628160428.53115-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250628160428.53115-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When CONFIG_DAMON_SYSFS is disabled, the selftests fail with the following
outputs,
not ok 2 selftests: damon: sysfs_update_schemes_tried_regions_wss_estimation.py # exit=1
not ok 3 selftests: damon: damos_quota.py # exit=1
not ok 4 selftests: damon: damos_quota_goal.py # exit=1
not ok 5 selftests: damon: damos_apply_interval.py # exit=1
not ok 6 selftests: damon: damos_tried_regions.py # exit=1
not ok 7 selftests: damon: damon_nr_regions.py # exit=1
not ok 11 selftests: damon: sysfs_update_schemes_tried_regions_hang.py # exit=1
The root cause of this issue is that all the testcases above do not check
the sysfs interface of DAMON whether it exists or not. With this patch
applied, all the testcases above now pass successfully.
Link: https://lkml.kernel.org/r/20250531093937.1555159-1-lienze@kylinos.cn
Signed-off-by: Enze Li <lienze@kylinos.cn>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_nr_regions.py starts DAMON, periodically collect number of regions
in snapshots, and see if it is in the requested range. The check code
assumes the numbers are sorted on the collection list, but there is no
such guarantee. Hence this can result in false positive test success.
Sort the list before doing the check.
Link: https://lkml.kernel.org/r/20250225222333.505646-4-sj@kernel.org
Fixes: 781497347d ("selftests/damon: implement test for min/max_nr_regions")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_nr_regions.py updates max_nr_regions to a number smaller than
expected number of real regions and confirms DAMON respect the harsh
limit. To give time for DAMON to make changes for the regions, 3
aggregation intervals (300 milliseconds) are given.
The internal mechanism works with not only the max_nr_regions, but also
sz_limit, though. It avoids merging region if that casn make region of
size larger than sz_limit. In the test, sz_limit is set too small to
achive the new max_nr_regions, unless it is updated for the new
min_nr_regions. But the update is done only once per operations set
update interval, which is one second by default.
Hence, the test randomly incurs false positive failures. Fix it by
setting the ops interval same to aggregation interval, to make sure
sz_limit is updated by the time of the check.
Link: https://lkml.kernel.org/r/20250225222333.505646-3-sj@kernel.org
Fixes: 8bf890c816 ("selftests/damon/damon_nr_regions: test online-tuned max_nr_regions")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/damon: three fixes for false results".
Fix three DAMON selftest bugs that cause two and one false positive
failures and successes.
This patch (of 3):
damos_quota.py assumes the quota will always exceeded. But whether quota
will be exceeded or not depend on the monitoring results. Actually the
monitored workload has chaning access pattern and hence sometimes the
quota may not really be exceeded. As a result, false positive test
failures happen. Expect how much time the quota will be exceeded by
checking the monitoring results, and use it instead of the naive
assumption.
Link: https://lkml.kernel.org/r/20250225222333.505646-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250225222333.505646-2-sj@kernel.org
Fixes: 51f58c9da1 ("selftests/damon: add a test for DAMOS quota")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damos_quota_goal.py selftest see if DAMOS quota goals tuning feature
increases or reduces the effective size quota for given score as expected.
The tuning feature sets the minimum quota size as one byte, so if the
effective size quota is already one, we cannot expect it further be
reduced. However the test is not aware of the edge case, and fails since
it shown no expected change of the effective quota. Handle the case by
updating the failure logic for no change to see if it was the case, and
simply skips to next test input.
Link: https://lkml.kernel.org/r/20250217182304.45215-1-sj@kernel.org
Fixes: f1c07c0a16 ("selftests/damon: add a test for DAMOS quota goal")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202502171423.b28a918d-lkp@intel.com
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org> [6.10.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When running selftests I encountered the following error message with
some damon tests:
# Traceback (most recent call last):
# File "[...]/damon/./damos_quota.py", line 7, in <module>
# import _damon_sysfs
# ModuleNotFoundError: No module named '_damon_sysfs'
Fix this by adding the _damon_sysfs.py file to TEST_FILES so that it
will be available when running the respective damon selftests.
Link: https://lkml.kernel.org/r/20241127-picks-visitor-7416685b-mheyne@amazon.de
Fixes: 306abb63a8 ("selftests/damon: implement a python module for test-purpose DAMON sysfs controls")
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests".
Fixup small broken window panes in DAMON selftests and kunit tests.
First four patches clean up DAMON debugfs interface selftests output, by
fixing segmentation fault of a test program (patch 1), removing
unnecessary debugging messages (patch 2), and hiding error messages from
expected failures (patches 3 and 4).
Following two patches fix copy-paste mistakes in DAMON Kconfig help
message that copied from debugfs kunit test (patch 5) and a comment on the
debugfs kunit test code (patch 6).
This patch (of 6):
'huge_count_read_write' crashes with segmentation fault when reading
DEPRECATED file of DAMON debugfs interface. This is not causing any
problem for users or other tests because the purpose of the test is just
ensuring the read is not causing kernel warning messages. Nonetheless, it
makes the output unnecessarily noisy, and the DEPRECATED file is not
properly being tested.
It happens because the size of the content of the file is larger than the
size of the buffer for the read. The file contains about 170 characters.
Increase the buffer size to 256 characters.
Link: https://lkml.kernel.org/r/20241028233058.283381-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20241028233058.283381-2-sj@kernel.org
Fixes: b4a002889d ("selftests/damon: test debugfs file reads/writes with huge count")
Signed-off-by: Andrew Paniakin <apanyaki@amazon.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Andrew Panyakin <apanyaki@amazon.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
