From nobody Sun Feb 8 18:15:55 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14C792F12DE; Sun, 26 Oct 2025 18:22:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761502946; cv=none; b=a5YcXVUrcglgKr+xV+Eavin1Q4Wi9fommoBdQ3Mcas++cT4f3sca0Yr03MYpnEP4BmXPCpL5PZLUFbvnUBcUslUtqx3A/5wzMRUdzVBYXPFVyVWJBvU7a6ZFGWmmn6NaRVVB2tZgwEroXpMqMiOCc+PJkIsQlkLQla7Fgm3iiqE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761502946; c=relaxed/simple; bh=HTEUhayo10VIIHTrpNQMg1meUMUdoEd6UZy7MJUO3rU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kXAkk9aAQ2em2rJjYkGGgvqAb3a4zf5iVj/9rj8XBWq/zfOnNcXCXoTPmJTsSIOje3X/egz4tTWWXuweDCiOLwr1Y5W4ufoM/SEKYe6bcqUXeRVke/XZyGtPMd6q/WndtV3ZZMMNOvTwVV5Va1T6ILhBWgZbig0V+4vQPLOdY10= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a8HhEKac; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a8HhEKac" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60492C4CEE7; Sun, 26 Oct 2025 18:22:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761502945; bh=HTEUhayo10VIIHTrpNQMg1meUMUdoEd6UZy7MJUO3rU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a8HhEKacHBy4+fTLed4bI/HXIzp7f0fyoBsAaukKkycunU/gHfrRznT04l5Hpi6XS QX+yv9feyV4/2phxDVXL10MnhFjxx3pKGIrkyHJQtabJihUZh/XefOqpuBm9A8qowW xjJz2FeVtH1Wyvt9RcslPpeX8osSGVQ1HybXCNpwN3s1z4GcByZrb3Ls7lV+Pfj8C2 ccYDEjAXXn8c+6zchlv/j26VcUS2ul230UE/6ve4dm63r+KmxbFvgOirEuG4nzIVlY +YRAHmcrGlWj7wl1ixuTisJQ4OPWlJKQWZB/EV9UJ0n+MZdKwHoJhdziAESyqM2Xiw iisJsBClf9h5A== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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/ad= min-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 p= rovides simplified access monitoring results statistics, namely idle time percentiles and estimated memory bandwidth. =20 +.. _damon_stat_monitoring_accuracy_overhead: + Monitoring Accuracy and Overhead =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D =20 @@ -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 sampl= ing 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-resulti= ng +intervals can be retrieved via ``aggr_interval_us`` :ref:`parameter +`. =20 Interface: Module Parameters =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D @@ -41,6 +45,18 @@ You can enable DAMON_STAT by setting the value of this p= arameter as ``Y``. Setting it as ``N`` disables DAMON_STAT. The default value is set by ``CONFIG_DAMON_STAT_ENABLED_DEFAULT`` build config option. =20 +.. _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 -------------------------- =20 --=20 2.47.3