'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'.

Signed-off-by: SeongJae Park sj@kernel.org --- .../selftests/damon/drgn_dump_damon_status.py | 161 ++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100755 tools/testing/selftests/damon/drgn_dump_damon_status.py

diff --git a/tools/testing/selftests/damon/drgn_dump_damon_status.py b/tools/testing/selftests/damon/drgn_dump_damon_status.py new file mode 100755 index 000000000000..333a0d0c4bff --- /dev/null +++ b/tools/testing/selftests/damon/drgn_dump_damon_status.py @@ -0,0 +1,161 @@ +#!/usr/bin/env drgn +# SPDX-License-Identifier: GPL-2.0 + +''' +Read DAMON context data and dump as a json string. +''' +import drgn +from drgn import FaultError, NULL, Object, cast, container_of, execscript, offsetof, reinterpret, sizeof +from drgn.helpers.common import * +from drgn.helpers.linux import * + +import json +import sys + +if "prog" not in globals(): + try: + prog = drgn.get_default_prog() + except drgn.NoDefaultProgramError: + prog = drgn.program_from_kernel() + drgn.set_default_prog(prog) + +def to_dict(object, attr_name_converter): + d = {} + for attr_name, converter in attr_name_converter: + d[attr_name] = converter(getattr(object, attr_name)) + return d + +def intervals_goal_to_dict(goal): + return to_dict(goal, [ + ['access_bp', int], + ['aggrs', int], + ['min_sample_us', int], + ['max_sample_us', int], + ]) + +def attrs_to_dict(attrs): + return to_dict(attrs, [ + ['sample_interval', int], + ['aggr_interval', int], + ['ops_update_interval', int], + ['intervals_goal', intervals_goal_to_dict], + ['min_nr_regions', int], + ['max_nr_regions', int], + ]) + +def addr_range_to_dict(addr_range): + return to_dict(addr_range, [ + ['start', int], + ['end', int], + ]) + +def region_to_dict(region): + return to_dict(region, [ + ['ar', addr_range_to_dict], + ['sampling_addr', int], + ['nr_accesses', int], + ['nr_accesses_bp', int], + ['age', int], + ]) + +def regions_to_list(regions): + return [region_to_dict(r) + for r in list_for_each_entry( + 'struct damon_region', regions.address_of_(), 'list')] + +def target_to_dict(target): + return to_dict(target, [ + ['pid', int], + ['nr_regions', int], + ['regions_list', regions_to_list], + ]) + +def targets_to_list(targets): + return [target_to_dict(t) + for t in list_for_each_entry( + 'struct damon_target', targets.address_of_(), 'list')] + +def damos_access_pattern_to_dict(pattern): + return to_dict(pattern, [ + ['min_sz_region', int], + ['max_sz_region', int], + ['min_nr_accesses', int], + ['max_nr_accesses', int], + ['min_age_region', int], + ['max_age_region', int], + ]) + +def damos_quota_goal_to_dict(goal): + return to_dict(goal, [ + ['metric', int], + ['target_value', int], + ['current_value', int], + ['last_psi_total', int], + ['nid', int], + ]) + +def damos_quota_goals_to_list(goals): + return [damos_quota_goal_to_dict(g) + for g in list_for_each_entry( + 'struct damos_quota_goal', goals.address_of_(), 'list')] + +def damos_quota_to_dict(quota): + return to_dict(quota, [ + ['reset_interval', int], + ['ms', int], ['sz', int], + ['goals', damos_quota_goals_to_list], + ['esz', int], + ['weight_sz', int], + ['weight_nr_accesses', int], + ['weight_age', int], + ]) + +def damos_watermarks_to_dict(watermarks): + return to_dict(watermarks, [ + ['metric', int], + ['interval', int], + ['high', int], ['mid', int], ['low', int], + ]) + +def scheme_to_dict(scheme): + return to_dict(scheme, [ + ['pattern', damos_access_pattern_to_dict], + ['action', int], + ['apply_interval_us', int], + ['quota', damos_quota_to_dict], + ['wmarks', damos_watermarks_to_dict], + ['target_nid', int], + ]) + +def schemes_to_list(schemes): + return [scheme_to_dict(s) + for s in list_for_each_entry( + 'struct damos', schemes.address_of_(), 'list')] + +def damon_ctx_to_dict(ctx): + return to_dict(ctx, [ + ['attrs', attrs_to_dict], + ['adaptive_targets', targets_to_list], + ['schemes', schemes_to_list], + ]) + +def main(): + if len(sys.argv) < 3: + print('Usage: %s <kdamond pid> <file>' % sys.argv[0]) + exit(1) + + pid = int(sys.argv[1]) + file_to_store = sys.argv[2] + + kthread_data = cast('struct kthread *', + find_task(prog, pid).worker_private).data + ctx = cast('struct damon_ctx *', kthread_data) + status = {'contexts': [damon_ctx_to_dict(ctx)]} + if file_to_store == 'stdout': + print(json.dumps(status, indent=4)) + else: + with open(file_to_store, 'w') as f: + json.dump(status, f, indent=4) + +if __name__ == '__main__': + main()

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.

Signed-off-by: SeongJae Park sj@kernel.org --- tools/testing/selftests/damon/Makefile | 1 + tools/testing/selftests/damon/sysfs.py | 42 ++++++++++++++++++++++++++ 2 files changed, 43 insertions(+) create mode 100755 tools/testing/selftests/damon/sysfs.py

diff --git a/tools/testing/selftests/damon/Makefile b/tools/testing/selftests/damon/Makefile index e888455e3cf8..5b230deb19e8 100644 --- a/tools/testing/selftests/damon/Makefile +++ b/tools/testing/selftests/damon/Makefile @@ -7,6 +7,7 @@ TEST_FILES = _damon_sysfs.py

# functionality tests TEST_PROGS += sysfs.sh +TEST_PROGS += sysfs.py TEST_PROGS += sysfs_update_schemes_tried_regions_wss_estimation.py TEST_PROGS += damos_quota.py damos_quota_goal.py damos_apply_interval.py TEST_PROGS += damos_tried_regions.py damon_nr_regions.py diff --git a/tools/testing/selftests/damon/sysfs.py b/tools/testing/selftests/damon/sysfs.py new file mode 100755 index 000000000000..4ff99db0d247 --- /dev/null +++ b/tools/testing/selftests/damon/sysfs.py @@ -0,0 +1,42 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0 + +import json +import os +import subprocess + +import _damon_sysfs + +def dump_damon_status_dict(pid): + file_dir = os.path.dirname(os.path.abspath(__file__)) + dump_script = os.path.join(file_dir, 'drgn_dump_damon_status.py') + rc = subprocess.call(['drgn', dump_script, pid, 'damon_dump_output'], + stderr=subprocess.DEVNULL) + if rc != 0: + return None, 'drgn fail' + try: + with open('damon_dump_output', 'r') as f: + return json.load(f), None + except Exception as e: + return None, 'json.load fail (%s)' % e + +def main(): + kdamonds = _damon_sysfs.Kdamonds( + [_damon_sysfs.Kdamond(contexts=[_damon_sysfs.DamonCtx()])]) + err = kdamonds.start() + if err is not None: + print('kdamond start failed: %s' % err) + exit(1) + + status, err = dump_damon_status_dict(kdamonds.kdamonds[0].pid) + if err is not None: + print(err) + exit(1) + + if len(status['contexts']) != 1: + print('number of contexts: %d' % len(status['contexts'])) + exit(1) + kdamonds.stop() + +if __name__ == '__main__': + main()

Add DAMON sysfs interface functionality tests for setup of basic adaptive targets parameters.

Signed-off-by: SeongJae Park sj@kernel.org --- tools/testing/selftests/damon/sysfs.py | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/damon/sysfs.py b/tools/testing/selftests/damon/sysfs.py index a721901a880d..3b085268f342 100755 --- a/tools/testing/selftests/damon/sysfs.py +++ b/tools/testing/selftests/damon/sysfs.py @@ -27,7 +27,9 @@ def fail(expectation, status):

def main(): kdamonds = _damon_sysfs.Kdamonds( - [_damon_sysfs.Kdamond(contexts=[_damon_sysfs.DamonCtx()])]) + [_damon_sysfs.Kdamond( + contexts=[_damon_sysfs.DamonCtx( + targets=[_damon_sysfs.DamonTarget(pid=-1)])])]) err = kdamonds.start() if err is not None: print('kdamond start failed: %s' % err) @@ -60,8 +62,9 @@ def main(): if attrs['max_nr_regions'] != 1000: fail('max_nr_regions')

- if ctx['adaptive_targets'] != []: - fail('adaptive_targets') + if ctx['adaptive_targets'] != [ + { 'pid': 0, 'nr_regions': 0, 'regions_list': []}]: + fail('adaptive targets', status)

if ctx['schemes'] != []: fail('schemes')