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Howlett" , David Hildenbrand , Jonathan Corbet , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , damon@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 7/8] Docs/admin-guide/mm/damon/stat: document aggr_interval_us parameter Date: Sun, 26 Oct 2025 11:22:12 -0700 Message-ID: <20251026182216.118200-8-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251026182216.118200-1-sj@kernel.org> References: <20251026182216.118200-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam05 X-Stat-Signature: nx195xydy6bac9a4q6xa9qbqbsrjtugm X-Rspam-User: X-Rspamd-Queue-Id: 26F88180003 X-HE-Tag: 1761502946-157686 X-HE-Meta: U2FsdGVkX1/L2vjXMWjP7R/KmAlVbHakHBI1hGk4FaUw8HkA5ajwAAHyuWJ5SrT2vGe1kQgvNs6y1ZgWUl5w4Jb1iTP+TXp2ejfWrw22GA1TL7T/zL9Qw6wuIhZKt0pFxUMWBwsVXTRpH37/hn10fGwWTi4Up07n6bWRZ1v+k/ec8sa2GrIDKeJKpC3pG1BAGv/8VEEvbzgWH3So9mQQK1RKJc0+k43KP41Wne/4EfGjL29/KWPyXLn45SbhSSxgvkNdNnXyY6/ati7ry+H3t7K5qUsic1oyfgd5pz/xzJ2xMh0BstMxHyrE8LNZOdVvRo7UvEYV/G9ke7CkV4YczupAve6l2YVBw45C3tW25Ar6/fZhQfG9rG5qBDQ0t52WZ/Zas26ro3xpBAzFUlh+Z9N0yjPuGUFKmkdBtPVoZ4V3jKsHMW7MqQs4pADd9SnuCDbEmb6n+Bw/3/iGgkWL4aunf5Mb5wQBH5ercMJje975n2OlzG90h8mmo2gf35ztgFa2isIXRyIetHiIm+ljlYKCWCza0NBqfBQ6UGd75wqgqAmguEduls+sGeZfVtn+pxjBw4ItM2ZX42kxc1QfcHPjvdWSWnMQNxj6LCcIi/I+uJakNiC3tUuO9Wp1TOUB2CwHqPaXa2Izs5EHixQHco5IQrvQ5drVKQId3OT3lwxZDlcAu4mUQCCI4J3YgCRIMC5hZUOWwW9HmcMGxAjjEsB8VfOQXwFZtEQq2rygjHMYKpplUbG1fvNzqO1xQz7n8mjMVmwqVsYYRr9rqOFqQ4DWqyFjwhTBzRAsgrlgNN6+QaCDU7wstpg0VvJHFISw1QhCNa+hiJImKZdgUq2pOBXAA2YOWWKunrolmfWXs4dfJIf1Vc6FroMwNSrYby89h+lZDykGffHNKdERIHjd+o8UR/SuhTTuVN1ZNRY+Au09S/LHq6Io37rJb9FVmXliWilRkX/AyZ+l/VqB+m7 TQYbjvAv NUkUDFLaskwa3y173nMeUHwwjiPlCO5tjYCM3Omb5xUVnUCcvXBzuW+POtbbjAJ6LHPevsWV7fL5XH7vbl3Qyo6+X0KF/Sy2W2A9O7ClDqpHCAhBUwRixaMh5NRoSPV7uEdjJxgXEHaqJGNKTwDmxP6p4xiDl3D+cThfqB0kVwihYtZue9rFvlM/J+ISQL4ibcDQVC0hpS1KzuhEyCSZj9p5vjgeCJU5hUh593xGaWUcmiInX2uuQeUHTwBEMrUchUbF7x+Nw2Q+3zyybPSqZvl6I9QvwGFsfdfCWInKUuJ2egr8EUbBZMlXWgXRi1bmpHDnJ 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: Commit cc7ceb1d14b0 ("mm/damon/stat: expose the current tuned aggregation interval"), has introduced 'aggr_interval_us' parameter for DAMON_STAT. But the new parameter is not yet documented. Document it on the usage document for the module. Signed-off-by: SeongJae Park --- Documentation/admin-guide/mm/damon/stat.rst | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/mm/damon/stat.rst b/Documentation/admin-guide/mm/damon/stat.rst index 20f540a9d3d2..754f98d47617 100644 --- a/Documentation/admin-guide/mm/damon/stat.rst +++ b/Documentation/admin-guide/mm/damon/stat.rst @@ -10,6 +10,8 @@ on the system's entire physical memory using DAMON, and provides simplified access monitoring results statistics, namely idle time percentiles and estimated memory bandwidth. +.. _damon_stat_monitoring_accuracy_overhead: + Monitoring Accuracy and Overhead ================================ @@ -19,7 +21,9 @@ overhead minimum. It auto-tunes the intervals aiming 4 % of observable access events to be captured in each snapshot, while limiting the resulting sampling interval to be 5 milliseconds in minimum and 10 seconds in maximum. On a few production server systems, it resulted in consuming only 0.x % single CPU time, -while capturing reasonable quality of access patterns. +while capturing reasonable quality of access patterns. The tuning-resulting +intervals can be retrieved via ``aggr_interval_us`` :ref:`parameter +`. Interface: Module Parameters ============================ @@ -41,6 +45,18 @@ You can enable DAMON_STAT by setting the value of this parameter as ``Y``. Setting it as ``N`` disables DAMON_STAT. The default value is set by ``CONFIG_DAMON_STAT_ENABLED_DEFAULT`` build config option. +.. _damon_stat_aggr_interval_us: + +aggr_interval_us +---------------- + +Auto-tuned aggregation time interval in microseconds. + +Users can read the aggregation interval of DAMON that is being used by the +DAMON instance for DAMON_STAT. It is :ref:`auto-tuned +` and therefore the value is +dynamically changed. + estimated_memory_bandwidth -------------------------- -- 2.47.3