'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()