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selftests/damon/damon_nr_regions: test online-tuned max_nr_regions

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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: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
SeongJae Park 2024-06-25 11:05:38 -07:00 committed by Andrew Morton
parent 5ac9adecf0
commit 8bf890c816
1 changed files with 60 additions and 0 deletions
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60
tools/testing/selftests/damon/damon_nr_regions.py
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@ -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()