linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: SeongJae Park <sj@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: SeongJae Park <sj@kernel.org>,
	"Liam R. Howlett" <Liam.Howlett@oracle.com>,
	David Hildenbrand <david@redhat.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
	Michal Hocko <mhocko@suse.com>, Mike Rapoport <rppt@kernel.org>,
	Suren Baghdasaryan <surenb@google.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	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	[thread overview]
Message-ID: <20251026182216.118200-8-sj@kernel.org> (raw)
In-Reply-To: <20251026182216.118200-1-sj@kernel.org>

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 <sj@kernel.org>
---
 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
+<damon_stat_aggr_interval_us>`.
 
 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
+<damon_stat_monitoring_accuracy_overhead>` and therefore the value is
+dynamically changed.
+
 estimated_memory_bandwidth
 --------------------------
 
-- 
2.47.3


  parent reply	other threads:[~2025-10-26 18:22 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-26 18:22 [PATCH 0/8] mm/damon: misc documentation fixups SeongJae Park
2025-10-26 18:22 ` [PATCH 1/8] mm/damon/core: fix wrong comment of damon_call() return timing SeongJae Park
2025-10-26 18:22 ` [PATCH 2/8] Docs/mm/damon/design: fix wrong link to intervals goal section SeongJae Park
2025-10-26 18:22 ` [PATCH 3/8] Docs/admin-guide/mm/damon/stat: fix a typo: s/sampling events/sampling interval/ SeongJae Park
2025-10-26 18:22 ` [PATCH 4/8] Docs/admin-guide/mm/damon/usage: document empty target regions commit behavior SeongJae Park
2025-10-26 18:22 ` [PATCH 5/8] Docs/admin-guide/mm/damon/reclaim: document addr_unit parameter SeongJae Park
2025-10-26 18:22 ` [PATCH 6/8] Docs/admin-guide/mm/damon/lru_sort: " SeongJae Park
2025-10-26 18:22 ` SeongJae Park [this message]
2025-10-26 18:22 ` [PATCH 8/8] Docs/admin-guide/mm/damon/stat: document negative idle time SeongJae Park

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20251026182216.118200-8-sj@kernel.org \
    --to=sj@kernel.org \
    --cc=Liam.Howlett@oracle.com \
    --cc=akpm@linux-foundation.org \
    --cc=corbet@lwn.net \
    --cc=damon@lists.linux.dev \
    --cc=david@redhat.com \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lorenzo.stoakes@oracle.com \
    --cc=mhocko@suse.com \
    --cc=rppt@kernel.org \
    --cc=surenb@google.com \
    --cc=vbabka@suse.cz \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox