Commit 51f58c9d authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

selftests/damon: add a test for DAMOS quota 

Add a selftest for verifying the DAMOS quota feature.  The test is very
similar to sysfs_update_schemes_tried_regions_wss_estimation.py.  It
starts an artificial workload of 20 MiB working set, run DAMON to find the
working set size, but with 1 MiB/100 ms size quota.  Then, it collect the
DAMON-found working set size every 100 ms and check if the quota was
always applied as expected.  For the confirmation, the tests shows the
stat-applied region size and the qt_exceeds stat.

Link: https://lkml.kernel.org/r/20240207203134.69976-5-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 a8622625

tools/testing/selftests/damon/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ TEST_PROGS += debugfs_rm_non_contexts.sh 
TEST_PROGS += sysfs.sh sysfs_update_removed_scheme_dir.sh

TEST_PROGS += sysfs_update_schemes_tried_regions_hang.py

TEST_PROGS += sysfs_update_schemes_tried_regions_wss_estimation.py

TEST_PROGS += damos_quota.py

TEST_PROGS += reclaim.sh lru_sort.sh



include ../lib.mk

tools/testing/selftests/damon/damos_quota.py

0 → 100644
+67 −0
Original line number Diff line number Diff line 
#!/usr/bin/env python3

# SPDX-License-Identifier: GPL-2.0



import subprocess

import time



import _damon_sysfs



def main():

    # access two 10 MiB memory regions, 2 second per each

    sz_region = 10 * 1024 * 1024

    proc = subprocess.Popen(['./access_memory', '2', '%d' % sz_region, '2000'])



    # Set quota up to 1 MiB per 100 ms

    sz_quota = 1024 * 1024 # 1 MiB

    quota_reset_interval = 100 # 100 ms

    kdamonds = _damon_sysfs.Kdamonds([_damon_sysfs.Kdamond(

            contexts=[_damon_sysfs.DamonCtx(

                ops='vaddr',

                targets=[_damon_sysfs.DamonTarget(pid=proc.pid)],

                schemes=[_damon_sysfs.Damos(

                    access_pattern=_damon_sysfs.DamosAccessPattern(

                        # >= 25% access rate, >= 200ms age

                        nr_accesses=[5, 20], age=[2, 2**64 - 1]),

                    quota=_damon_sysfs.DamosQuota(

                        sz=sz_quota, reset_interval_ms=quota_reset_interval)

                    )] # schemes

                )] # contexts

            )]) # kdamonds



    err = kdamonds.start()

    if err != None:

        print('kdamond start failed: %s' % err)

        exit(1)



    wss_collected = []

    nr_quota_exceeds = 0

    while proc.poll() == None:

        time.sleep(0.1)

        err = kdamonds.kdamonds[0].update_schemes_tried_bytes()

        if err != None:

            print('tried bytes update failed: %s' % err)

            exit(1)

        err = kdamonds.kdamonds[0].update_schemes_stats()

        if err != None:

            print('stats update failed: %s' % err)

            exit(1)



        scheme = kdamonds.kdamonds[0].contexts[0].schemes[0]

        wss_collected.append(scheme.tried_bytes)

        nr_quota_exceeds = scheme.stats.qt_exceeds



    wss_collected.sort()

    for wss in wss_collected:

        if wss > sz_quota:

            print('quota is not kept: %s > %s' % (wss, sz_quota))

            print('collected samples are as below')

            print('\n'.join(['%d' % wss for wss in wss_collected]))

            exit(1)



    if nr_quota_exceeds < len(wss_collected):

        print('quota is not always exceeded: %d > %d' %

              (len(wss_collected), nr_quota_exceeds))

        exit(1)



if __name__ == '__main__':

    main()