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b=dKdZa4MVbzSBmai1pABwghOZq1xaPwH4Vm34+d4LyPVpyPqgr41f7niT1RSxfFx0A BoL3y1DhuuRcB4NnBTCu+1d4XpmDo/+Y9CO1ohjPsR5Bzxb8k7MNtjKGDgu1F0d+Cm wUickhpNF6LciTPOTcz9M/zAnda92MHgkJQNzXHf90RTofgeLATa/iprkxk+kyWJPV uIQg3Pu0aarI11cyesYSCHnx/lht7H6fwLDItsoUKCiyfgDFLnm7CnwRslQQAdTQvV W8uF1whQ+xynG1k8Owbo25RkEW47AdXsnDwYa+nk/zse4a/C54oV8+BJMLti0BNF8+ E3r7/z2lr51Bg== From: SeongJae Park To: Cc: SeongJae Park , Andrew Morton , Brendan Higgins , David Gow , Shuah Khan , damon@lists.linux.dev, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 00/10] mm/damon: add optional debugging-purpose sanity checks Date: Sat, 21 Feb 2026 11:36:17 -0800 Message-ID: <20260221193629.19332-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: B0A9580003 X-Stat-Signature: 47m4hijxdaqj4y4ar8kafbdpmdr7rk7y X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1771702595-508008 X-HE-Meta: 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 RTclZEDV r9SFhO1WAeU39VAvUkZboDWfEImRBRBHnqPr7DdrYxwKgmBlgksfb18b1zpMR5sKbvxNa+lORcA6ZGTxkRT6uKt88tHY25N7YscuEbLi4B/pcv1fgGY3f0SKAOf0BUqEhndRrRmW8CboMSTI1Ik0xtSVBqO2NKzJCrD/ZwX5goADHrguPPyMsw7+WvBTakb8KhC3zQ/TcQoUpp3ZUHWH4Pumcq7nmSPNn+HknFUXpBKwVOdY= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: DAMON code has a few assumptions that can be critical if violated. Validating the assumptions in code can be useful at finding such critical bugs. I was actually adding some such additional sanity checks in my personal tree, and those were useful at finding bugs that I made during the development of new patches. We also found [1] sometimes the assumptions are misunderstood. The validation can work as good documentation for such cases. Add some of such debugging purpose sanity checks. Because those additional checks can impose more overhead, make those only optional via new config, CONFIG_DAMON_DEBUG_SANITY, that is recommended for only development and test setups. And as recommended, enable it for DAMON kunit tests and selftests. [1] https://lore.kernel.org/20251231070029.79682-1-sj@kernel.org SeongJae Park (10): mm/damon: add CONFIG_DAMON_DEBUG_SANITY mm/damon/core: add damon_new_region() debug_sanity check mm/damon/core: add damon_del_region() debug_sanity check mm/damon/core: add damon_nr_regions() debug_sanity check mm/damon/core: add damon_merge_two_regions() debug_sanity check mm/damon/core: add damon_merge_regions_of() debug_sanity check mm/damon/core: add damon_split_region_at() debug_sanity check mm/damon/core: add damon_reset_aggregated() debug_sanity check mm/damon/tests/.kunitconifg: enable DAMON_DEBUG_SANITY tools/testing/selftests/damon/config: enable DAMON_DEBUG_SANITY mm/damon/Kconfig | 11 +++ mm/damon/core.c | 139 +++++++++++++++++++++++++++ mm/damon/tests/.kunitconfig | 3 + tools/testing/selftests/damon/config | 1 + 4 files changed, 154 insertions(+) base-commit: e059221c54896e36c8fc320029648e9013b382ea -- 2.47.3