The patch titled Subject: selftests/damon/damon_nr_regions: test online-tuned max_nr_regions has been added to the -mm mm-unstable branch. Its filename is selftests-damon-damon_nr_regions-test-online-tuned-max_nr_regions.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-damon-damon_nr_regions-test-online-tuned-max_nr_regions.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: selftests/damon/damon_nr_regions: test online-tuned max_nr_regions Date: Tue, 25 Jun 2024 11:05:38 -0700 User could update max_nr_regions parameter while DAMON is running to a value that smaller than the current number of regions that DAMON is seeing. Such update could be done for reducing the monitoring overhead. In the case, DAMON should merge regions aggressively more than normal situation to ensure the new limit is successfully applied. Implement a kselftest to ensure that. Link: https://lkml.kernel.org/r/20240625180538.73134-9-sj@xxxxxxxxxx Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/damon/damon_nr_regions.py | 60 ++++++++++++ 1 file changed, 60 insertions(+) --- a/tools/testing/selftests/damon/damon_nr_regions.py~selftests-damon-damon_nr_regions-test-online-tuned-max_nr_regions +++ a/tools/testing/selftests/damon/damon_nr_regions.py @@ -81,5 +81,65 @@ def main(): # test max_nr_regions smaller than real nr regions test_nr_regions(15, 3, 10) + # test online-tuned max_nr_regions that smaller than real nr regions + sz_region = 10 * 1024 * 1024 + proc = subprocess.Popen(['./access_memory_even', '14', '%d' % sz_region]) + + # stat every monitored regions + kdamonds = _damon_sysfs.Kdamonds([_damon_sysfs.Kdamond( + contexts=[_damon_sysfs.DamonCtx( + monitoring_attrs=_damon_sysfs.DamonAttrs( + min_nr_regions=10, max_nr_regions=1000), + ops='vaddr', + targets=[_damon_sysfs.DamonTarget(pid=proc.pid)], + schemes=[_damon_sysfs.Damos(action='stat', + )] # schemes + )] # contexts + )]) # kdamonds + + err = kdamonds.start() + if err is not None: + proc.terminate() + print('kdamond start failed: %s' % err) + exit(1) + + # wait until the real regions are found + time.sleep(3) + + attrs = kdamonds.kdamonds[0].contexts[0].monitoring_attrs + attrs.min_nr_regions = 3 + attrs.max_nr_regions = 7 + err = kdamonds.kdamonds[0].commit() + if err is not None: + proc.terminate() + print('commit failed: %s' % err) + exit(1) + # wait for next merge operation is executed + time.sleep(0.3) + + err = kdamonds.kdamonds[0].update_schemes_tried_regions() + if err is not None: + proc.terminate() + print('tried regions update failed: %s' % err) + exit(1) + + scheme = kdamonds.kdamonds[0].contexts[0].schemes[0] + if scheme.tried_regions is None: + proc.terminate() + print('tried regions is not collected') + exit(1) + + nr_tried_regions = len(scheme.tried_regions) + if nr_tried_regions <= 0: + proc.terminate() + print('tried regions is not created') + exit(1) + proc.terminate() + + if nr_tried_regions > 7: + print('fail online-tuned max_nr_regions: %d > 7' % nr_tried_regions) + exit(1) + print('pass online-tuned max_nr_regions') + if __name__ == '__main__': main() _ Patches currently in -mm which might be from sj@xxxxxxxxxx are mm-damon-core-merge-regions-aggressively-when-max_nr_regions-is-unmet.patch docs-mm-damon-maintainer-profile-introduce-hackermail.patch docs-mm-damon-maintainer-profile-document-damon-community-meetups.patch selftests-damon-access_memory-use-user-defined-region-size.patch selftests-damon-_damon_sysfs-support-schemes_update_tried_regions.patch selftests-damon-implement-a-program-for-even-numbered-memory-regions-access.patch selftests-damon-implement-damos-tried-regions-test.patch selftests-damon-_damon_sysfs-implement-kdamonds-stop-function.patch selftests-damon-implement-test-for-min-max_nr_regions.patch _damon_sysfs-implement-commit-for-online-parameters-update.patch selftests-damon-damon_nr_regions-test-online-tuned-max_nr_regions.patch