Commit 8bf890c8 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

selftests/damon/damon_nr_regions: test online-tuned max_nr_regions 

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@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 5ac9adec

tools/testing/selftests/damon/damon_nr_regions.py

+60 −0
Original line number Diff line number Diff line
@@ -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()