github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-27 09:36:22 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

selftests/damon/sysfs.py: pause DAMON before dumping status

Browse Source 
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.

Link: https://lore.kernel.org/20260427151231.113429-11-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
SeongJae Park 2026-04-27 08:12:29 -07:00 committed by Andrew Morton
parent e88be73275
commit cb1a7622c9
1 changed files with 38 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
tools/testing/selftests/damon/sysfs.py
View File

@ -198,18 +198,55 @@ def assert_ctx_committed(ctx, dump):
assert_true(dump['pause'] == ctx.pause, 'pause', dump)
def assert_ctxs_committed(kdamonds):
ctxs_paused_for_dump = []
kdamonds_paused_for_dump = []
# pause for safe state dumping
for kd in kdamonds.kdamonds:
for ctx in kd.contexts:
if ctx.pause is False:
ctx.pause = True
ctxs_paused_for_dump.append(ctx)
if not kd in kdamonds_paused_for_dump:
kdamonds_paused_for_dump.append(kd)
if kd in kdamonds_paused_for_dump:
err = kd.commit()
if err is not None:
print('pause fail (%s)' % err)
kdamonds.stop()
exit(1)
status, err = dump_damon_status_dict(kdamonds.kdamonds[0].pid)
if err is not None:
print(err)
kdamonds.stop()
exit(1)
# resume contexts paused for safe state dumping
for ctx in ctxs_paused_for_dump:
ctx.pause = False
for kd in kdamonds_paused_for_dump:
err = kd.commit()
if err is not None:
print('resume fail (%s)' % err)
kdamonds.stop()
exit(1)
# restore for comparison
for ctx in ctxs_paused_for_dump:
ctx.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])
# restore for the caller
for kd in kdamonds.kdamonds:
for ctx in kd.contexts:
if ctx in ctxs_paused_for_dump:
ctx.pause = False
def main():
kdamonds = _damon_sysfs.Kdamonds(
[_damon_sysfs.Kdamond(
@ -309,6 +346,7 @@ 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)