[PATCH 0/6] mm/damon: fix misc bugs in DAMON modules

SeongJae Park posted 6 patches 3 months ago
mm/damon/lru_sort.c   |  5 ++++-
mm/damon/reclaim.c    |  9 ++++++---
samples/damon/mtier.c | 13 +++++++++++++
samples/damon/prcl.c  | 13 +++++++++++++
samples/damon/wsse.c  | 15 ++++++++++++++-
5 files changed, 50 insertions(+), 5 deletions(-)
[PATCH 0/6] mm/damon: fix misc bugs in DAMON modules
Posted by SeongJae Park 3 months ago
From manual code review, I found below bugs in DAMON modules.

DAMON sample modules crash if those are enabled at boot time, via kernel
command line.  A similar issue was found and fixed on DAMON non-sample
modules in the past, but we didn't check that for sample modules.

DAMON non-sample modules are not setting 'enabled' parameters
accordingly when real enabling is failed.  Honggyu found and fixed[1]
this type of bugs in DAMON sample modules, and my inspection was
motivated by the great work.  Kudos to Honggyu.

Finally, DAMON_RECLIAM is mistakenly losing scheme internal status due
to misuse of damon_commit_ctx().  DAMON_LRU_SORT has a similar misuse,
but fortunately it is not causing real status loss.

Fix the bugs.  Since these are similar patterns of bugs that were found
in the past, it would be better to add tests or refactor the code, in
future.

Note that the fix of the second bug for DAMON_STAT is sent
separately[2], since it is a fix for a bug in mm-unstable tree at the
moment.  Also as mentioned above, DAMON_LRU_SORT also has a misuse of
damon_commit_ctx(), but it is not causing a real issue, hence the fix is
not included in this series.  I will post it later.

[1] https://lore.kernel.org/20250702000205.1921-1-honggyu.kim@sk.com
[2] https://lore.kernel.org/20250706184750.36588-1-sj@kernel.org

SeongJae Park (6):
  samples/damon/wsse: fix boot time enable handling
  samples/damon/prcl: fix boot time enable crash
  samples/damon/mtier: support boot time enable setup
  mm/damon/reclaim: reset enabled when DAMON start failed
  mm/damon/lru_sort: reset enabled when DAMON start failed
  mm/damon/reclaim: use parameter context correctly

 mm/damon/lru_sort.c   |  5 ++++-
 mm/damon/reclaim.c    |  9 ++++++---
 samples/damon/mtier.c | 13 +++++++++++++
 samples/damon/prcl.c  | 13 +++++++++++++
 samples/damon/wsse.c  | 15 ++++++++++++++-
 5 files changed, 50 insertions(+), 5 deletions(-)


base-commit: a555ad24c884e9f4ee2f2a0184f5b7b89c8d4a6e
-- 
2.39.5