The sysfs.py test commits DAMON parameters, dump the internal DAMON state, and show if the parameters are committed as expected using the dumped state. While the dumping is ongoing, DAMON is alive. It can make internal changes including addition and removal of regions. It can therefore make a race that can result in false test results. Pause DAMON execution during the state dumping to avoid such races.
Signed-off-by: SeongJae Park <[email protected]> --- tools/testing/selftests/damon/sysfs.py | 27 ++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/tools/testing/selftests/damon/sysfs.py b/tools/testing/selftests/damon/sysfs.py index e6d34ba05893f..a1a29f1a7c27b 100755 --- a/tools/testing/selftests/damon/sysfs.py +++ b/tools/testing/selftests/damon/sysfs.py @@ -193,18 +193,44 @@ def assert_ctx_committed(ctx, dump): assert_true(dump['pause'] == ctx.pause, 'pause', dump) def assert_ctxs_committed(kdamonds): + paused_for_dump = False + if kdamonds.kdamonds[0].contexts[0].pause is False: + kdamonds.kdamonds[0].contexts[0].pause = True + err = kdamonds.kdamonds[0].commit() + if err is not None: + print('pause fail (%s)' % err) + kdamonds.stop() + exit(1) + paused_for_dump = True + status, err = dump_damon_status_dict(kdamonds.kdamonds[0].pid) if err is not None: print(err) kdamonds.stop() exit(1) + if paused_for_dump: + # resume + kdamonds.kdamonds[0].contexts[0].pause = False + err = kdamonds.kdamonds[0].commit() + if err is not None: + print('resume fail (%s)' % err) + kdamonds.stop() + exit(1) + + # restore for comparison + kdamonds.kdamonds[0].contexts[0].pause = True + ctxs = kdamonds.kdamonds[0].contexts dump = status['contexts'] assert_true(len(ctxs) == len(dump), 'ctxs length', dump) for idx, ctx in enumerate(ctxs): assert_ctx_committed(ctx, dump[idx]) + if paused_for_dump: + # restore for the caller + kdamonds.kdamonds[0].contexts[0].pause = False + def main(): kdamonds = _damon_sysfs.Kdamonds( [_damon_sysfs.Kdamond( @@ -302,6 +328,7 @@ def main(): print('kdamond start failed: %s' % err) exit(1) kdamonds.kdamonds[0].contexts[0].targets[1].obsolete = True + kdamonds.kdamonds[0].contexts[0].pause = True kdamonds.kdamonds[0].commit() del kdamonds.kdamonds[0].contexts[0].targets[1] assert_ctxs_committed(kdamonds) -- 2.47.3
