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h=From:To:Cc:Subject:Date; b=WbgTNZgMZLscSz4b9bOglPLjoxPxYzqBAN5UdFSBXU8hAZhkAz3/o5OJO6wAmedZy xexJs8Se7ZJZCjcQh/17dpRbaD9q2++1LnXAcKhFmaLg0gGsxu9ZfcGVKVdL9JB3X7 oNdyMW6T2niYH6mcj7+cdpKnFa1aBaSzQXCJKlTHAY9L3OjdQclE1HTgGPNB94Z8/1 3NtWdoTL4qWvA+t5wfqwddo5oHlBz7dsYmuLEyGQc9J+EkTZPuniaT7dHNiwJ2S8cr NTyIf2WyTNjV4mRPLTX9skSSqA2jVbzqUp+x7hG/i8ThBDNOjQCFD600RifBHmMbpN 4hsHqPnYKAsew== From: SJ Park To: Cc: SJ Park , "# 5 . 15 . x" , Andrew Morton , Brendan Higgins , David Gow , Fernand Sieber , Leonard Foerster , SeongJae Park , Shakeel Butt , 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 0/5] mm/damon: unurgent fixes for infinite loop, NULL de-ref and races Date: Sat, 11 Jul 2026 11:04:03 -0700 Message-ID: <20260711180409.82093-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: ECC9A18000A X-Stat-Signature: auosik8fiya378jjtohu1sk6i6k1kdqc X-HE-Tag: 1783793060-919931 X-HE-Meta: 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 bdJ4liUW jIGthA+8Lyn81Jto1l+5RWvAq76ndpXqB/W3+KbgPZWo07Nn0iUHQni+Pj3UZymwSLpAXDc82pOZR6KbSWXiGFsCiKVpaxyrbgnYXngMFRRVS3LRyABlRbX0y7aLOz33SxHI5BNUlzEpnitQaVd0IIiKjXldY8FBtKCNB2lg7FZ8HecVRwsOVg/FbXklcFxUGCK/SZPhrytJPNkpsJ2yqjhdSzg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Sashiko found a few issues in DAMON that could cause infinite loop, NULL dereference and monitoring results degradation. The first two sounds scary but the infinite loop happens only under unreasonable user setup. The NULL dereference is only in a unit test. Monitoring results degradation is trivial since it is only best-effort, and those happens from only unlikely races. Still those are bugs that better to fix if possible. Fix those. SJ Park (5): mm/damon/core: avoid infinite kdamond_merge_regions() internal loop mm/damon/tests/core-kunit: catch test failure in test_merge_regions_of() mm/damon/vaddr: drop last same folio access check optimization mm/damon/paddr: drop last same folio access check reuse optimization mm/damon/sysfs: read ops_id only once mm/damon/core.c | 13 +++++++++---- mm/damon/paddr.c | 20 ++++---------------- mm/damon/sysfs.c | 6 ++++-- mm/damon/tests/core-kunit.h | 3 +++ mm/damon/vaddr.c | 26 ++++---------------------- 5 files changed, 24 insertions(+), 44 deletions(-) base-commit: 65b3b6001701d46d5360097bdc90dfa1c06a1239 -- 2.47.3