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Howlett" , David Hildenbrand , Jonathan Corbet , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Randy Dunlap , SJ Park , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , damon@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 2/3] docs/mm/damon/design: difference between watermarks and nr_snapshots Date: Mon, 31 Aug 2026 08:02:25 -0700 Message-ID: <20260831150227.83416-3-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260831150227.83416-1-sj@kernel.org> References: <20260831150227.83416-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: no6j7r8fby47rby7bjxw4xp41xaon5qo X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 9BB8C4000F X-Rspam-User: X-HE-Tag: 1788188557-809457 X-HE-Meta: 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 R7tRbMN6 7yZooYhEMK/HircLSC5vPApwBPZHj6xy92bkjIoRboic7+x3BNlJ9rJDtkdtWla/ItiX6UGFFi2BPKvgLe534PX0cv7/s4X+uP11Ada3yXWS+YI3TkrkxIflx4lnmlCU1MziQiAOkYgUmJKzran2/LjMIpr3mMVMdqREorL0NsNIjz1DUrIZJtT4jBxD0Duf4nmAW7WfEf214BvAZTlw55kbvQPAgN8emTtyrwGm56fRYsRed1Zm0uQmD5H9HKZy6dzB7b7Y6Ffkru82lXnPjLCtKMy6l7CrKdY7hxTgkMG+S1mFFqez5uyYHfw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Liew Rui Yan Explain the difference between nr_snapshots reaches max_nr_snapshots and watermarks. Signed-off-by: Liew Rui Yan Reviewed-by: SJ Park Signed-off-by: SJ Park --- Documentation/mm/damon/design.rst | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst index af94fc27890b8..74170a2285501 100644 --- a/Documentation/mm/damon/design.rst +++ b/Documentation/mm/damon/design.rst @@ -874,7 +874,8 @@ the action to the region will fail. Unlike normal stats, ``max_nr_snapshots`` is set by users. If it is set as non-zero and ``nr_snapshots`` be same to or greater than ``nr_snapshots``, the -scheme is deactivated. +scheme is deactivated. Note that, unlike watermarks, even if a scheme's +``nr_snapshots`` reaches ``max_nr_snapshots``, monitoring will not stop. To know how user-space can read the stats via :ref:`DAMON sysfs interface `, refer to :ref:s`stats ` part of the -- 2.47.3