kernel/linux.git/tools/testing/selftests/damon, branch v7.0-rc7

selftests/damon/wss_estimation: deduplicate failed samples output

2026-01-31T22:22:45+00:00

When the test fails, it shows whole sampled working set size measurements. The purpose is showing the distribution of the measured values, to let the tester know if it was just intermittent failure. Multiple same values on the output are therefore unnecessary. It was not a big deal since the test was failing only once in the past. But the test can now fail multiple times with increased working set size, until it passes or the working set size reaches a limit. Hence the noisy output can be quite long and annoying. Print only the deduplicated distribution information. Link: https://lkml.kernel.org/r/20260117020731.226785-6-sj@kernel.org Signed-off-by: SeongJae Park Cc: Shuah Khan Signed-off-by: Andrew Morton

selftests/damon/wss_estimation: ensure number of collected wss

2026-01-31T22:22:44+00:00

DAMON selftest for working set size estimation collects DAMON's working set size measurements of the running artificial memory access generator program until the program is finished. Depending on how quickly the program finishes, and how quickly DAMON starts, the number of collected working set size measurements may vary, and make the test results unreliable. Ensure it collects 40 measurements by using the repeat mode of the artificial memory access generator program, and finish the measurements only after the desired number of collections are made. Link: https://lkml.kernel.org/r/20260117020731.226785-5-sj@kernel.org Signed-off-by: SeongJae Park Cc: Shuah Khan Signed-off-by: Andrew Morton

selftests/damon/access_memory: add repeat mode

2026-01-31T22:22:44+00:00

'access_memory' is an artificial memory access generator program that is used for a few DAMON selftests. It accesses a given number of regions one by one only once, and exits. Depending on systems, the test workload may exit faster than expected, making the tests unreliable. For reliable control of the artificial memory access pattern, add a mode to make it repeat running. Link: https://lkml.kernel.org/r/20260117020731.226785-4-sj@kernel.org Signed-off-by: SeongJae Park Cc: Shuah Khan Signed-off-by: Andrew Morton

selftests/damon/wss_estimation: test for up to 160 MiB working set size

2026-01-31T22:22:44+00:00

DAMON reads and writes Accessed bits of page tables without manual TLB flush for two reasons. First, it minimizes the overhead. Second, real systems that need DAMON are expected to be memory intensive enough to cause periodic TLB flushes. For test setups that use small test workloads, however, the system's TLB could be big enough to cover whole or most accesses of the test workload. In this case, no page table walk happens and DAMON cannot show any access from the test workload. The test workload for DAMON's working set size estimation selftest is such a case. It accesses only 10 MiB working set, and it turned out there are test setups that have TLBs large enough to cover the 10 MiB data accesses. As a result, the test fails depending on the test machine. Make it more reliable by trying larger working sets up to 160 MiB when it fails. Link: https://lkml.kernel.org/r/20260117020731.226785-3-sj@kernel.org Signed-off-by: SeongJae Park Cc: Shuah Khan Signed-off-by: Andrew Morton

selftests/damon/sysfs_memcg_path_leak.sh: use kmemleak

2026-01-31T22:22:44+00:00

Patch series "selftests/damon: improve leak detection and wss estimation reliability". Two DAMON selftets, namely 'sysfs_memcg_leak' and 'sysfs_update_schemes_tried_regions_wss_estimation' frequently show intermittent failures due to their unreliable leak detection and working set size estimation. Make those more reliable. This patch (of 5): sysfs_memcg_path_leak.sh determines if the memory leak has happened by seeing if Slab size on /proc/meminfo increases more than expected after an action. Depending on the system and background workloads, the reasonable expectation varies. For the reason, the test frequently shows intermittent failures. Use kmemleak, which is much more reliable and correct, instead. Link: https://lkml.kernel.org/r/20260117020731.226785-1-sj@kernel.org Link: https://lkml.kernel.org/r/20260117020731.226785-2-sj@kernel.org Signed-off-by: SeongJae Park Cc: Shuah Khan Signed-off-by: Andrew Morton

selftests/damon/sysfs.py: merge DAMON status dumping into commitment assertion

2025-11-20T21:44:01+00:00

For each test case, sysfs.py makes changes to DAMON, dumps DAMON internal status and asserts the expectation is met. The dumping part should be the same for all cases, so it is duplicated for each test case. Which means it is easy to make mistakes. Actually a few of those duplicates are not turning DAMON off in case of the dumping failure. It makes following selftests that need to turn DAMON on fails with -EBUSY. Merge the status dumping into commitment assertion with proper dumping failure handling, to deduplicate and avoid the unnecessary following tests failures. Link: https://lkml.kernel.org/r/20251112154114.66053-8-sj@kernel.org Signed-off-by: SeongJae Park Cc: Bill Wendling Cc: Brendan Higgins Cc: David Gow Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jonathan Corbet Cc: Justin Stitt Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Miguel Ojeda Cc: Mike Rapoport Cc: Nathan Chancellor Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm/damon: rename damos->filters to damos->core_filters

2025-11-20T21:44:01+00:00

DAMOS filters that are handled by the ops layer are linked to damos->ops_filters. Owing to the ops_ prefix on the name, it is easy to understand it is for ops layer handled filters. The other types of filters, which are handled by the core layer, are linked to damos->filters. Because of the name, it is easy to confuse the list is there for not only core layer handled ones but all filters. Avoid such confusions by renaming the field to core_filters. Link: https://lkml.kernel.org/r/20251112154114.66053-3-sj@kernel.org Signed-off-by: SeongJae Park Cc: Bill Wendling Cc: Brendan Higgins Cc: David Gow Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jonathan Corbet Cc: Justin Stitt Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Miguel Ojeda Cc: Mike Rapoport Cc: Nathan Chancellor Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/damon/sysfs: add obsolete_target test

2025-11-17T01:28:25+00:00

A new DAMON sysfs file for pin-point target removal, namely obsolete_target, has been added. Add a test for the functionality. It starts DAMON with three monitoring target processes, mark one in the middle as obsolete, commit it, and confirm the internal DAMON status is updated to remove the target in the middle. Link: https://lkml.kernel.org/r/20251023012535.69625-10-sj@kernel.org Signed-off-by: SeongJae Park Cc: Bijan Tabatabai Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

sysfs.py: extend assert_ctx_committed() for monitoring targets

2025-11-17T01:28:25+00:00

assert_ctx_committed() is not asserting monitoring targets commitment, since all existing callers of the function assume no target changes. Extend it for future usage. Link: https://lkml.kernel.org/r/20251023012535.69625-9-sj@kernel.org Signed-off-by: SeongJae Park Cc: Bijan Tabatabai Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

drgn_dump_damon_status: dump damon_target->obsolete

2025-11-17T01:28:24+00:00

A new field of damon_target for pin-point target removal, namely obsolete, has newly been added. Extend drgn_dump_damon_status.py to dump it, for easily writing a future DAMON selftests of it. Link: https://lkml.kernel.org/r/20251023012535.69625-8-sj@kernel.org Signed-off-by: SeongJae Park Cc: Bijan Tabatabai Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton